@font-face {
  font-family: 'OC-Kyokasho';
  src: url('/Online-Class/assets/css/fonts/HGSKyokashotai-03.ttf') format('truetype');
  font-display: swap;
}

@font-face {
  font-family: 'OC-Gothic';
  src: url('/Online-Class/assets/css/fonts/DFHSG-W5.woff') format('woff');
  font-display: swap;
}

@font-face {
  font-family: 'OC-Maru';
  src: url('/Online-Class/assets/css/fonts/DFMARU.woff') format('woff');
  font-display: swap;
}

@font-face {
  font-family: 'OC-Reisho';
  src: url('/Online-Class/assets/css/fonts/DFLEISHO.woff') format('woff');
  font-display: swap;
}

@font-face {
  font-family: 'OC-Pop';
  src: url('/Online-Class/assets/css/fonts/DFPOP1.woff') format('woff');
  font-display: swap;
}

:root {
  --app-bg: #002818;
  --panel-bg: rgba(0, 40, 24, 0.92);
  --panel-border: rgba(148, 184, 163, 0.18);
  --text-main: #e5e7eb;
  --text-muted: #cbd5e1;
  --brand: #7dd3fc;
  --success: #34d399;
  --danger: #fb7185;
  --board-bg: rgba(0, 40, 24, 1);
  --board-safe-left: 40px;
  --board-safe-top: 116px;
  --board-right-width: 200px;
  --fixed-problem-height: 150px;
  --fixed-problem-offset: var(--fixed-problem-height);
  --shadow-soft: 0 18px 48px rgba(0, 23, 15, 0.28);
  --radius-large: 18px;
  --radius-medium: 12px;
  --radius-small: 8px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  font-family: 'Segoe UI', 'Hiragino Sans', 'Yu Gothic UI', sans-serif;
  color: var(--text-main);
  background: linear-gradient(180deg, #002315 0%, #002818 100%);
}

button,
input,
select,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

a {
  color: inherit;
  text-decoration: none;
}

.auth-body,
.portal-body {
  min-height: 100vh;
}

.auth-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.auth-card {
  width: min(100%, 520px);
  background: rgba(0, 40, 24, 0.88);
  border: 1px solid var(--panel-border);
  border-radius: 20px;
  box-shadow: var(--shadow-soft);
  padding: 24px;
}

.auth-card__header,
.auth-card__footer {
  display: grid;
  gap: 10px;
}

.auth-form {
  display: grid;
  gap: 16px;
  margin: 24px 0;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 10px 14px;
  border-radius: 999px;
  background: rgba(125, 252, 211, 0.12);
  color: var(--brand);
  font-weight: 700;
  letter-spacing: 0.04em;
}

.field {
  display: grid;
  gap: 4px;
}

.field input {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid rgba(148, 184, 163, 0.32);
  border-radius: 10px;
  background: rgba(0, 40, 24, 0.9);
  color: var(--text-main);
}

.alert {
  padding: 12px 14px;
  border-radius: 10px;
}

.alert--error {
  background: rgba(251, 113, 133, 0.14);
  border: 1px solid rgba(251, 113, 133, 0.36);
  color: #fecdd3;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 32px;
  padding: 10px 16px;
  border: 1px solid transparent;
  border-radius: 10px;
  transition: background-color 0.2s ease, border-color 0.2s ease, opacity 0.2s ease;
}

.button--primary {
  background: #2563eb;
  color: #fff;
}

.button--ghost {
  border-color: rgba(148, 184, 163, 0.28);
  background: rgba(0, 40, 24, 0.75);
  color: var(--text-main);
}


.button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.button--small {
  min-height: 34px;
  padding: 6px 10px;
}

.button--block {
  width: 100%;
}

/* hidden 属性を display 指定より優先して非表示にする */
[hidden] {
  display: none !important;
}

.sample-account-list,
.feature-list {
  margin: 0;
  padding-left: 20px;
  display: grid;
  gap: 8px;
}

.portal-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  padding: 24px;
}

.portal-header__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.portal-main {
  display: grid;
  gap: 24px;
  padding: 0 24px 24px;
}

.portal-section {
  background: rgba(0, 40, 24, 0.82);
  border: 1px solid var(--panel-border);
  border-radius: 18px;
  padding: 20px;
  box-shadow: var(--shadow-soft);
}

.badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 6px 10px;
  border-radius: 999px;
  background: rgba(125, 252, 211, 0.14);
  color: #dbeafe;
  font-size: 0.9rem;
}

.portal-card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.portal-card {
  display: grid;
  gap: 14px;
  background: rgba(0, 40, 24, 0.76);
  border: 1px solid rgba(148, 184, 163, 0.22);
  border-radius: 14px;
  padding: 16px;
}

.meta-list {
  display: grid;
  gap: 10px;
  margin: 0;
}

.meta-list div {
  display: grid;
  gap: 4px;
}

.meta-list dt {
  color: var(--text-muted);
  font-size: 0.74rem;
}

.meta-list dd {
  margin: 0;
}

.empty-state {
  padding: 16px;
  border: 1px dashed rgba(148, 184, 163, 0.3);
  border-radius: 10px;
  color: var(--text-muted);
}

.board-body {
  min-height: 100vh;
  overflow: hidden;
}

.board-app {
  position: relative;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
  background: #002818;
}

.board-status {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(0, 40, 24, 0.78);
  border: 1px solid rgba(148, 184, 168, 0.22);
  font-size: 0.86rem;
  color: var(--text-main);
}

.board-status--inline {
  width: 100%;
  justify-content: center;
}

.board-logo-layer {
  position: absolute;
  left: 0;
  top: 0;
  z-index: 40;
  width: 215px;
  height: 76px;
  display: flex;
  align-items: flex-start;
  justify-content: flex-start;
  margin: 0;
  padding: 0;
  pointer-events: none;
}

.board-logo-mark {
  width: 159px;
  height: 56px;
  margin: 10px;
  padding: 0;
  border: 0;
  background-color: transparent;
  background-image: var(--board-logo-image, none);
  background-repeat: no-repeat;
  background-position: center;
  background-size: 100% 100%;
  display: block;
}

.board-leftbar-layer {
  position: absolute;
  left: 0;
  top: 0;
  z-index: 30;
  width: var(--board-safe-left);
  height: 100vh;
  padding: 0 2px 8px;
  display: grid;
  grid-auto-rows: max-content;
  gap: 8px;
  background: rgba(0, 40, 24, 0.88);
  border-right: 1px solid rgba(148, 184, 163, 0.2);
}

.leftbar-spacer {
  min-height: 44px;
}

.tool-button {
  position: relative;
  display: grid;
  place-items: center;
  width: 100%;
  aspect-ratio: 1 / 1;
  min-height: 0;
  padding: 2px;
  border-radius: 12px;
  border: 1px solid rgba(148, 184, 163, 0.2);
  background: rgba(0, 40, 24, 0.72);
  color: var(--text-main);
  font-size: 0.78rem;
}

.tool-button span {
  display: none;
}

.tool-button.is-active {
  background: rgba(0, 250, 150, 0.25);
  border-color: rgba(0, 250, 150, 0.5);
}

.tool-button[data-tooltip]::after {
  content: attr(data-tooltip);
  position: absolute;
  left: calc(100% + 10px);
  top: 50%;
  transform: translateY(-50%) translateX(-4px);
  min-width: max-content;
  padding: 6px 8px;
  border-radius: 8px;
  background: rgba(0, 40, 24, 0.96);
  border: 1px solid rgba(148, 184, 163, 0.22);
  color: var(--text-main);
  font-size: 0.74rem;
  line-height: 1.2;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.16s ease, transform 0.16s ease;
}

.tool-button:hover::after,
.tool-button:focus-visible::after {
  opacity: 1;
  transform: translateY(-50%) translateX(0);
}

.tool-button.is-disabled,
.tool-button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.board-topbar-layer {
  position: absolute;
  top: 0;
  left: 0;
  right: var(--board-right-width);
  z-index: 30;
  height: var(--board-safe-top);
  background: rgba(0, 40, 24, 0.88);
  border-bottom: 1px solid rgba(148, 184, 163, 0.2);
}

.topbar-spacer {
  width: 175px;
  height: 100%;
  float: left;
  pointer-events: none;
}

.board-topbar-content {
  margin-left: 175px;
  height: 100%;
  display: grid;
  grid-template-rows: minmax(0, auto) minmax(0, auto);
  gap: 4px;
  padding: 6px 8px;
  overflow-x: auto;
}

.topbar-row {
  display: flex;
  align-items: center;
  gap: 4px;
  min-width: max-content;
}

.topbar-row--common {
  justify-content: space-between;
}

.topbar-group {
  display: flex;
  align-items: center;
  gap: 4px;
  min-width: max-content;
}

.topbar-group--common {
  flex-wrap: nowrap;
}

.topbar-group--actions {
  margin-left: 8px;
}

.topbar-tool-panel {
  display: none;
  align-items: center;
  gap: 6px;
  min-height: 32px;
}

.topbar-tool-panel.is-active {
  display: flex;
}

.topbar-tool-panel--select {
  flex-wrap: wrap;
  align-items: flex-end;
  row-gap: 4px;
}

.selection-metrics-grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(52px, 62px));
  gap: 4px 6px;
  align-items: end;
}

.selection-metrics-grid .compact-field--number input {
  width: 100%;
}

.selection-metrics-apply {
  align-self: end;
  min-height: 30px;
  padding: 6px 10px;
  font-size: 0.78rem;
}

.topbar-tool-panel--select-actions {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
  gap: 6px;
}

.selection-action-button {
  min-height: 28px;
  padding: 0 10px;
  white-space: nowrap;
}

.topbar-helper-text {
  color: var(--text-muted);
  font-size: 0.72rem;
  white-space: nowrap;
}

.compact-field {
  display: inline-grid;
  gap: 2px;
  font-size: 0.74rem;
}

.compact-field span {
  font-size: 0.66rem;
  letter-spacing: 0.01em;
}

.compact-field input[type='range'] {
  width: 96px;
}

.compact-field.compact-field--tiny {
  font-size: 0.64rem;
}

.compact-field.compact-field--tiny span {
  font-size: 0.62rem;
}

.compact-field--select select,
.compact-field--number input {
  width: 76px;
}



.current-image-box {
  display: inline-block;
  align-items: center;
  flex: 0 0 120px;
  min-width: 0;
  width: 120px;
  min-height: 32px;
  max-width: 120px;
  padding: 6px 10px;
  border: 1px solid rgba(148, 184, 163, 0.28);
  border-radius: 10px;
  background: rgba(0, 40, 24, 0.75);
  color: var(--text-muted);
  font-size: 0.74rem;
  line-height: 18px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  vertical-align: middle;
}


.toolbar-icon-button {
  position: relative;
  min-width: 32px;
  width: 32px;
  padding: 0;
  font-size: 0.92rem;
  flex: 0 0 auto;
}

.toolbar-icon-button[data-tooltip]::after {
  content: attr(data-tooltip);
  position: absolute;
  left: 50%;
  bottom: calc(100% + 8px);
  transform: translateX(-50%) translateY(4px);
  min-width: max-content;
  max-width: 220px;
  padding: 6px 8px;
  border-radius: 8px;
  background: rgba(0, 40, 24, 0.96);
  border: 1px solid rgba(148, 184, 163, 0.22);
  box-shadow: 0 12px 24px rgba(0, 25, 15, 0.24);
  color: var(--text-main);
  font-size: 0.76rem;
  line-height: 1.3;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.16s ease, transform 0.16s ease;
}

.toolbar-icon-button:hover::after,
.toolbar-icon-button:focus-visible::after {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.toolbar-icon-button.is-active {
  background: rgba(255, 255, 255, 0.18);
  border-color: rgba(255, 255, 255, 0.42);
  color: #ffffff;
}

.board-rightbar-layer {
  position: absolute;
  right: 0;
  top: 0;
  z-index: 30;
  width: var(--board-right-width);
  height: 100vh;
  padding: 12px;
  background: rgba(0, 40, 24, 0.88);
  border-left: 1px solid rgba(148, 184, 163, 0.2);
}

.rightbar-box {
  display: grid;
  gap: 12px;
  padding: 12px;
  border-radius: 14px;
  background: rgba(0, 40, 24, 0.76);
  border: 1px solid rgba(148, 184, 163, 0.18);
}

.board-workspace-layer {
  position: absolute;
  left: var(--board-safe-left);
  top: var(--board-safe-top);
  right: var(--board-right-width);
  bottom: 0;
  z-index: 10;
  overflow: hidden;
}

.fixed-problem-panel {
  position: absolute;
  left: 0;
  top: 0;
  right: 0;
  z-index: 20;
  height: var(--fixed-problem-height);
  padding: 0;
  background: rgba(0, 40, 24, 1);
  border-bottom: 1px solid rgba(148, 184, 163, 0.2);
  overflow: hidden;
}

.fixed-problem-panel.is-collapsed {
  border-bottom: none;
}

.fixed-problem-panel__body {
  position: absolute;
  inset: 0;
  min-height: 0;
  margin: 0;
  padding: 0;
  overflow: hidden;
}

.fixed-problem-panel.is-collapsed .fixed-problem-panel__body {
  display: none;
}

.board-canvas-shell {
  position: absolute;
  left: 0;
  right: 0;
  top: var(--fixed-problem-offset);
  bottom: 0;
  background: rgba(0,35,21,1);
}

.board-canvas-scroll {
  width: 100%;
  height: 100%;
  overflow: auto;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
  overflow-anchor: none;
}

.board-canvas-stage {
  position: relative;
  width: 1050px;
  height: 1485px;
  margin: 0 auto;
  background: var(--board-bg);
}

.board-canvas-zoom-layer {
  position: absolute;
  left: 0;
  top: 0;
  width: 1050px;
  height: 1485px;
  transform-origin: 0 0;
  will-change: transform;
}

#boardRenderCanvas,
#boardInteractionCanvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

#boardInteractionCanvas {
  z-index: 2;
  touch-action: none;
}

@media (max-width: 1024px) {
  :root {
    --board-safe-left: 72px;
    --board-right-width: 0px;
  }

  .board-rightbar-layer {
    display: none;
  }

  .board-topbar-layer {
    right: 0;
  }

  .board-workspace-layer {
    right: 0;
  }
}

@media (max-width: 767px) {
  :root {
    --board-safe-left: 0px;
    --board-safe-top: 64px;
    --fixed-problem-height: 120px;
  }

  .board-leftbar-layer {
    left: 0;
    right: 0;
    top: auto;
    bottom: 0;
    width: 100vw;
    height: calc(82px + env(safe-area-inset-bottom, 0px));
    padding: 8px 10px calc(8px + env(safe-area-inset-bottom, 0px));
    display: flex;
    align-items: center;
    gap: 8px;
    overflow-x: auto;
    border-right: none;
    border-top: 1px solid rgba(148, 184, 163, 0.2);
  }

  .leftbar-spacer {
    display: none;
  }

  .tool-button {
    min-width: 58px;
    min-height: 50px;
  }

  .board-topbar-layer {
    left: 0;
    height: var(--board-safe-top);
  }

  .topbar-spacer {
    width: 175px;
  }

  .board-topbar-content {
    margin-left: 175px;
    overflow-x: auto;
  }

  .board-workspace-layer {
    left: 0;
    bottom: calc(82px + env(safe-area-inset-bottom, 0px));
  }

  .board-canvas-stage {
    width: 100%;
    min-width: 768px;
  }

}

.alert--success {
  background: rgba(52, 211, 153, 0.14);
  border: 1px solid rgba(52, 211, 153, 0.36);
  color: #d1fae5;
}

.portal-form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.portal-form-card {
  display: grid;
  gap: 12px;
  background: rgba(0, 40, 24, 0.76);
  border: 1px solid rgba(148, 184, 163, 0.22);
  border-radius: 14px;
  padding: 16px;
}

.portal-form-card h3 {
  margin: 0;
}

.portal-form-card input,
.portal-form-card select,
.portal-form-card textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid rgba(148, 184, 163, 0.32);
  border-radius: 10px;
  background: rgba(0, 40, 24, 0.9);
  color: var(--text-main);
}

.portal-inline-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.compact-check-field {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 32px;
  padding: 0 8px;
  border: 1px solid rgba(148, 184, 163, 0.28);
  border-radius: 10px;
  background: rgba(0, 40, 24, 0.75);
}

.compact-check-field input {
  width: auto;
}

.compact-field--text {
  min-width: 200px;
}

.fixed-problem-panel__actions {
  position: absolute;
  top: 8px;
  right: 8px;
  z-index: 3;
  display: flex;
  gap: 8px;
}

.fixed-problem-panel__body {
  display: flex;
  align-items: center;
  justify-content: center;
}

.fixed-problem-image {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
  border: 1px solid rgba(148, 184, 163, 0.2);
  border-radius: 0;
  background: rgba(0, 40, 24, 1);
}

.fixed-problem-empty {
  display: grid;
  width: 100%;
  height: 100%;
  place-items: center;
  padding: 12px;
  color: rgba(226, 232, 240, 0.76);
  font-size: 14px;
  letter-spacing: 0.04em;
  text-align: center;
  background: rgba(0, 40, 24, 1);
}

.fixed-problem-empty[hidden] {
  display: none !important;
}

@media (max-width: 767px) {
  .portal-inline-grid {
    grid-template-columns: 1fr;
  }

  .compact-field--text {
    min-width: 180px;
  }
}


.section-header-row {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.helper-text {
  margin: 0;
  color: var(--text-sub);
  font-size: 0.92rem;
}

.empty-card {
  padding: 18px;
  border: 1px dashed rgba(148, 184, 163, 0.32);
  border-radius: 14px;
  background: rgba(0, 40, 24, 0.52);
}

.portal-tree-list {
  display: grid;
  gap: 16px;
}

.tree-card {
  display: grid;
  gap: 12px;
  padding: 16px;
  border-radius: 16px;
  border: 1px solid rgba(148, 184, 163, 0.22);
  background: rgba(0, 40, 24, 0.7);
}

.tree-card--page {
  background: rgba(0, 40, 24, 0.62);
}

.tree-card--subpage {
  background: rgba(2, 18, 12, 0.44);
}

.tree-card__header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.tree-card__header h3,
.tree-card__header h4,
.tree-card__header h5 {
  margin: 0;
}

.tree-kicker {
  color: #93c5fd;
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.tree-meta-inline {
  margin: 6px 0 0;
  color: var(--text-sub);
  font-size: 0.92rem;
}

.tree-actions-inline {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.inline-form {
  display: inline-flex;
}

.inline-form--compact {
  margin: 0;
}

.tree-edit-form {
  display: grid;
  gap: 12px;
}

.tree-edit-form__actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.tree-card__children {
  display: grid;
  gap: 12px;
  margin-left: 16px;
}

.portal-inline-grid--two {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.portal-archive-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.archive-card {
  display: grid;
  gap: 12px;
  padding: 16px;
  border-radius: 14px;
  border: 1px solid rgba(148, 184, 163, 0.22);
  background: rgba(0, 40, 24, 0.68);
}

.archive-card h3 {
  margin: 0;
}

.archive-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 12px;
  background: rgba(2, 18, 12, 0.42);
}

.archive-empty,
.archive-subtext {
  margin: 0;
  color: var(--text-sub);
  font-size: 0.9rem;
}

.rightbar-text {
  margin: 0;
  color: var(--text-main);
  line-height: 1.6;
  white-space: pre-wrap;
}

.board-navigator-backdrop[hidden],
.board-navigator-panel[hidden] {
  display: none !important;
}

.board-navigator-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 25, 15, 0.56);
  z-index: 36;
}

.board-navigator-panel {
  position: fixed;
  top: calc(var(--board-safe-top) + 12px);
  right: 216px;
  width: min(420px, calc(100vw - 260px));
  max-height: calc(100vh - var(--board-safe-top) - 24px);
  display: grid;
  grid-template-rows: auto 1fr;
  border-radius: 18px;
  border: 1px solid rgba(148, 184, 163, 0.24);
  background: rgba(0, 40, 24, 0.96);
  box-shadow: 0 24px 48px rgba(0, 25, 15, 0.34);
  z-index: 37;
  overflow: hidden;
}

.board-navigator-panel__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
  border-bottom: 1px solid rgba(148, 184, 163, 0.18);
}

.board-navigator-panel__header h2 {
  margin: 0;
  font-size: 0.92rem;
}

.board-navigator-panel__body {
  overflow: auto;
  padding: 14px 16px 18px;
  display: grid;
  gap: 14px;
}

.navigator-note-block,
.navigator-page-block {
  display: grid;
  gap: 8px;
}

.navigator-note-block h3,
.navigator-page-block h4 {
  margin: 0;
}

.navigator-page-block {
  padding-left: 12px;
}

.navigator-subpage-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 6px;
}

.navigator-subpage-link {
  display: grid;
  gap: 4px;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid rgba(148, 184, 163, 0.18);
  background: rgba(2, 18, 12, 0.38);
  color: var(--text-main);
  text-decoration: none;
}

.navigator-subpage-link small {
  color: var(--text-sub);
}

.navigator-subpage-link.is-current {
  border-color: rgba(96, 165, 250, 0.48);
  background: rgba(30, 64, 175, 0.24);
}

@media (max-width: 1024px) {
  .board-navigator-panel {
    right: 12px;
    width: min(420px, calc(100vw - 24px));
  }
}

@media (max-width: 767px) {
  .portal-inline-grid--two {
    grid-template-columns: 1fr;
  }

  .tree-card__children {
    margin-left: 0;
  }

  .archive-row {
    align-items: flex-start;
    flex-direction: column;
  }

  .board-navigator-panel {
    top: calc(var(--board-safe-top) + 8px);
    right: 8px;
    left: 8px;
    width: auto;
    max-height: calc(100vh - var(--board-safe-top) - 16px);
  }
}

.compact-check-field--tiny {
  min-height: 30px;
  padding: 0 7px;
  font-size: 0.68rem;
}

.compact-check-field--tiny span {
  font-size: 0.64rem;
}

.topbar-tool-panel[hidden] {
  display: none !important;
}


.topbar-tool-panel[data-tool-panel="graph"] {
  flex-wrap: wrap;
  row-gap: 4px;
}

.graph-expression-field {
  min-width: 260px;
}

.compact-field--mini input {
  width: 72px;
}

.compact-field--range input {
  width: 120px;
}

:root {
  --board-safe-top: 78px;
  --right-status-start-top: 208px;
}

.board-leftbar-layer {
  top: var(--board-safe-top);
  height: calc(100vh - var(--board-safe-top));
  padding: 4px 4px 10px;
  overflow: visible;
}

.tool-group {
  position: relative;
}

.tool-group-toggle {
  font-size: 0.9rem;
}

.tool-group-menu {
  position: absolute;
  left: calc(100% + 6px);
  top: 0;
  z-index: 45;
  display: grid;
  gap: 6px;
  width: 42px;
  padding: 4px;
  border-radius: 16px;
  background: rgba(0, 40, 24, 0.98);
  border: 1px solid rgba(148, 184, 163, 0.22);
  box-shadow: var(--shadow-soft);
}

.tool-group.is-open .tool-group-menu {
  display: grid;
}

.tool-group-menu[hidden] {
  display: none !important;
}

.tool-button--subtool {
  aspect-ratio: 1 / 1;
  min-height: 38px;
}

.tool-group-toggle.is-active {
  background: rgba(0, 250, 150, 0.25);
  border-color: rgba(0, 250, 150, 0.6);
}

.board-topbar-layer {
  height: var(--board-safe-top);
}

.board-topbar-content {
  margin-left: 175px;
  height: 100%;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  gap: 2px;
  padding: 2px 4px 4px;
  overflow: hidden;
}

.topbar-toolbar-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 6px;
  min-width: 0;
}

.topbar-toolbar-meta {
  display: grid;
  gap: 2px;
  min-width: 0;
}

.topbar-toolbar-kicker {
  font-size: 0.64rem;
  color: var(--text-muted);
  letter-spacing: 0.08em;
}

.topbar-toolbar-meta strong {
  font-size: 0.92rem;
  color: var(--text-main);
}

.topbar-toolbar-actions {
  display: flex;
  align-items: center;
  gap: 2px;
  flex-wrap: nowrap;
}

.topbar-category-strip {
  display: flex;
  align-items: center;
  gap: 2px;
  min-width: 0;
  overflow-x: auto;
  padding: 0;
}

.toolbar-category-button {
  flex: 0 0 auto;
  min-height: 22px;
  padding: 2px 8px;
  border-radius: 999px;
  border: 1px solid rgba(148, 184, 163, 0.2);
  background: rgba(0, 40, 24, 0.72);
  color: var(--text-main);
  font-size: 0.64rem;
  line-height: 1;
  white-space: nowrap;
}

.toolbar-category-button.is-active {
  background: rgba(0, 250, 150, 0.25);
  border-color: rgba(0, 250, 150, 0.5);
}

.topbar-category-body {
  min-height: 0;
  padding: 3px 5px;
  border-radius: 10px;
  background: rgba(0, 40, 24, 0.72);
  border: 1px solid rgba(148, 184, 163, 0.18);
  overflow-x: visible;
  overflow-y: hidden;
}

.topbar-tool-panel {
  display: none;
  align-items: center;
  align-content: center;
  gap: 4px;
  flex-wrap: nowrap;
  min-height: 32px;
  min-width: max-content;
}

.topbar-tool-panel.is-active {
  display: flex;
}

.toolbar-wide-field input {
  min-width: 200px;
}
.topbar-category-body .compact-field {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  font-size: 0.64rem;
}

.topbar-category-body .compact-field span {
  font-size: 0.54rem;
  white-space: nowrap;
}

.topbar-category-body .compact-field input[type='color'] {
  width: 26px;
  min-width: 26px;
  height: 20px;
  padding: 0;
}

.topbar-category-body .compact-field input[type='range'] {
  width: 72px;
}

.topbar-category-body .compact-field--select select,
.topbar-category-body .compact-field--number input,
.topbar-category-body .compact-field--mini input {
  width: 58px;
}

.topbar-category-body .compact-check-field {
  min-height: 22px;
  padding: 0 5px;
  gap: 3px;
  font-size: 0.62rem;
}

.topbar-category-body .button--small.selection-metrics-apply {
  min-height: 22px;
  padding: 0 7px;
}


.topbar-tool-panel--graph-basic .toolbar-wide-field input {
  min-width: 260px;
}

.topbar-tool-panel--graph-range,
.topbar-tool-panel--graph-divisions,
.topbar-tool-panel--graph-integral,
.topbar-tool-panel--image,
.topbar-tool-panel--image-pdf,
.topbar-tool-panel--image-layer,
.topbar-tool-panel--image-processing {
  justify-content: flex-start;
}

.topbar-tool-panel--graph-range .compact-field--mini input,
.topbar-tool-panel--graph-divisions .compact-field--mini input,
.topbar-tool-panel--graph-integral .compact-field--mini input {
  width: 66px;
}

.topbar-helper-text {
  display: none;
}

.topbar-tool-panel--graph-display {
  row-gap: 4px;
}

.topbar-tool-panel--image {
  row-gap: 4px;
}

.topbar-helper-text {
  max-width: none;
}

.board-rightbar-layer {
  top: 0;
  padding-top: var(--right-status-start-top);
  display: flex;
  justify-content: flex-end;
  overflow: hidden;
}

.board-side-toggle {
  position: absolute;
  right: 8px;
  bottom: 12px;
  z-index: 26;
  min-width: 34px;
  height: 34px;
  padding: 0 10px;
  border-radius: 999px;
  border: 1px solid rgba(148, 184, 163, 0.22);
  background: rgba(0, 40, 24, 0.92);
  color: var(--text-main);
  box-shadow: var(--shadow-soft);
}

.board-side-toggle.is-open {
  visibility: hidden;
  opacity: 0;
  pointer-events: none;
}

.right-status-panel {
  position: absolute;
  top: var(--right-status-start-top);
  right: 8px;
  bottom: 56px;
  width: calc(100% - 12px);
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  gap: 8px;
  padding: 8px;
  border-radius: 16px;
  background: rgba(0, 40, 24, 0.92);
  border: 1px solid rgba(148, 184, 163, 0.18);
  box-shadow: var(--shadow-soft);
  transform: translateX(calc(100% + 16px));
  transition: transform 0.22s ease;
  overflow: hidden;
}

.right-status-panel.is-open {
  transform: translateX(0);
}

.right-status-panel__header {
  display: grid;
  gap: 8px;
}

.right-status-panel__header h2,
.right-status-panel__body h3 {
  margin: 0;
}

.right-status-panel__header-actions {
  display: grid;
  gap: 8px;
}

.right-status-panel__close {
  justify-self: end;
  min-width: 38px;
}

.right-status-panel__body {
  display: grid;
  gap: 8px;
  overflow-y: auto;
  padding-right: 2px;
}

.status-panel-box {
  display: grid;
  gap: 8px;
  padding: 8px;
  border-radius: 14px;
  background: rgba(0, 25, 15, 0.28);
  border: 1px solid rgba(148, 184, 163, 0.12);
}

.status-panel-box--text {
  gap: 6px;
}

.meta-list--compact {
  gap: 6px;
}

.meta-list--compact dt,
.meta-list--compact dd,
.status-panel-box--text .rightbar-text {
  font-size: 0.64rem;
}

.meta-list--compact dd {
  text-align: right;
}

@media (max-width: 1024px) {
  :root {
    --board-safe-top: 74px;
  }
}

@media (max-width: 767px) {
  :root {
    --board-safe-top: 70px;
    --board-right-width: 184px;
  }

  .board-topbar-content {
    margin-left: 176px;
    grid-template-rows: auto minmax(0, 1fr);
    padding: 4px 6px 6px;
  }

  .topbar-toolbar-header {
    gap: 4px;
  }

  .topbar-toolbar-actions {
    gap: 2px;
  }

  .toolbar-category-button {
    min-height: 21px;
    padding: 2px 7px;
    font-size: 0.62rem;
  }

  .topbar-category-body {
    padding: 3px 5px;
  }

  .tool-group-menu {
    left: calc(100% + 6px);
    right: auto;
    top: 0;
    bottom: auto;
    width: 62px;
    grid-auto-flow: row;
  }

  .right-status-panel {
    bottom: 28px;
    width: calc(100% - 12px);
    right: 6px;
    top: var(--right-status-start-top);
  }

  .board-side-toggle {
    right: 6px;
    bottom: 8px;
  }

  .topbar-tool-panel--graph-basic .toolbar-wide-field input,
  .toolbar-wide-field input {
    min-width: 168px;
  }
}


/* ===== Phase 19: バー色統一・固定問題収納・右上時計領域確保 ===== */
:root {
  --board-bar-bg: rgba(0, 0, 0, 1);
  --right-status-start-top: 200px;
}

.board-leftbar-layer,
.board-topbar-layer,
.board-rightbar-layer,
.tool-group-menu,
.topbar-category-body,
.right-status-panel,
.board-side-toggle {
  background: var(--board-bar-bg) !important;
}

.toolbar-category-button {
  background: var(--board-bar-bg);
}

.board-leftbar-layer {
  border-right-color: rgba(148, 184, 163, 0.18);
}

.board-topbar-layer {
  border-bottom-color: rgba(148, 184, 163, 0.18);
}

.board-rightbar-layer {
  padding: 0 !important;
  border-left-color: rgba(148, 184, 163, 0.18);
}

.board-zoom-panel {
  position: absolute;
  left: 0;
  right: 46px;
  bottom: 0;
  z-index: 25;
  padding: 2px;
  margin: 0;
  border: none;
  border-radius: 0;
  background: rgba(0, 0, 0, 0.94);
  box-shadow: none;
}

.board-zoom-panel__row {
  display: flex;
  align-items: center;
  gap: 2px;
  min-width: 0;
  margin: 0;
  padding: 0;
}

.board-zoom-panel__field {
  display: inline-flex;
  align-items: center;
  justify-content: flex-end;
  gap: 1px;
  min-width: 0;
  margin: 0;
  padding: 0;
  color: var(--text-main);
  font-size: 0.5rem;
  line-height: 1;
  white-space: nowrap;
}

.board-zoom-panel__field input {
  width: 45px;
  min-width: 0;
  height: 18px;
  margin: 0;
  padding: 0 1px;
  background-color: rgba(0, 0, 0, 1.0);
  text-align: right;
  font-size: 0.52rem;
  color: rgba(255, 255, 255, 1.0);
  border-radius: 0;
  border: none;
  outline: none;
  appearance: textfield;
  -moz-appearance: textfield;
}

.board-zoom-panel__field input::-webkit-outer-spin-button,
.board-zoom-panel__field input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.board-zoom-panel__field span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 7px;
  font-size: 0.42rem;
  line-height: 1;
  cursor: pointer;
  user-select: none;
}

.board-zoom-panel__slider {
  flex: 0 1 106px;
  width: 106px;
  min-width: 0;
  margin: 0;
  accent-color: rgba(255, 255, 255, 0.92);
}

.right-clock-slot {
  position: absolute;
  top: 0;
  right: 0;
  width: 200px;
  height: 200px;
  margin: 0;
  padding: 0;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
}

.right-clock-slot__frame {
  display: block;
  width: 200px;
  height: 200px;
  margin: 0;
  padding: 0;
  border: 0;
  background: transparent;
}

.right-status-panel {
  top: var(--right-status-start-top) !important;
  right: 0 !important;
  bottom: 24px !important;
  width: var(--board-right-width) !important;
  padding: 8px 8px 10px;
  border-radius: 0;
  border-left: none;
  border-right: none;
}

.board-side-toggle {
  right: 8px;
  bottom: 8px;
}

.fixed-problem-panel {
  transition: transform 0.22s ease, opacity 0.22s ease, visibility 0.22s ease;
  transform: translateY(0);
  opacity: 1;
  visibility: visible;
}

.fixed-problem-panel.is-collapsed {
  border-bottom: none;
  transform: translateY(calc(-1 * var(--fixed-problem-height)));
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.fixed-problem-panel.is-collapsed .fixed-problem-panel__actions {
  display: none;
}

.fixed-problem-reveal-button {
  position: absolute;
  top: 8px;
  right: 8px;
  z-index: 24;
}

@media (max-width: 1024px) {
  .right-clock-slot {
    display: none;
  }
}


/* ===== Blackboard scrollbar: left side / subtle blend ===== */
@media (min-width: 768px) {
  .board-canvas-scroll {
    direction: ltr;
    scrollbar-width: thin;
    scrollbar-color: rgba(196, 214, 205, 0.24) rgba(0, 40, 24, 0.18);
  }

  .board-canvas-scroll > * {
    direction: ltr;
  }

  .board-canvas-scroll::-webkit-scrollbar {
    width: 8px;
    height: 8px;
  }

  .board-canvas-scroll::-webkit-scrollbar-track {
    background: rgba(0, 40, 24, 0.14);
  }

  .board-canvas-scroll::-webkit-scrollbar-thumb {
    border-radius: 999px;
    background: rgba(196, 214, 205, 0.20);
    border: 1px solid rgba(0, 40, 24, 0.10);
  }

  .board-canvas-scroll::-webkit-scrollbar-thumb:hover {
    background: rgba(196, 214, 205, 0.30);
  }

  .board-canvas-scroll::-webkit-scrollbar-corner {
    background: transparent;
  }
}


.board-print-preview-root {
  display: none;
}

.board-print-preview-page {
  width: 190mm;
  margin: 0 auto;
  background: #ffffff;
  break-after: page;
  page-break-after: always;
}

.board-print-preview-page:last-child {
  break-after: auto;
  page-break-after: auto;
}

.board-print-preview-page canvas {
  display: block;
  width: 100%;
  height: auto;
  background: #ffffff;
}

@page {
  size: A4 portrait;
  margin: 10mm;
}

@media print {
  html,
  body {
    width: auto;
    height: auto;
    margin: 0;
    padding: 0;
    background: #ffffff;
    overflow: visible;
  }

  body.board-print-mode .board-app {
    display: none !important;
  }

  body.board-print-mode .board-print-preview-root {
    display: block !important;
  }

  .board-print-preview-root {
    display: none;
  }
}


.toolbar-text-popup-guide {
  display: flex;
  flex-direction: column;
  gap: 4px;
  max-width: 420px;
  padding: 8px 10px;
  border: 1px solid rgba(148, 184, 163, 0.22);
  border-radius: 10px;
  background: rgba(0, 40, 24, 0.72);
  color: var(--text-subtle);
  font-size: 12px;
  line-height: 1.45;
}

.toolbar-text-popup-guide strong {
  color: var(--text-main);
  font-size: 13px;
}

.toolbar-text-hidden-state[hidden] {
  display: none !important;
}


.toolbar-wide-field--textarea {
  align-items: flex-start;
}

.toolbar-wide-field--textarea textarea {
  min-width: 240px;
  min-height: 58px;
  resize: vertical;
  line-height: 1.35;
}

.topbar-category-body textarea,
.topbar-category-body select,
.topbar-category-body input {
  background: rgba(0, 40, 24, 0.82);
  color: var(--text-main);
  border: 1px solid rgba(148, 184, 163, 0.22);
  border-radius: 8px;
}

.topbar-category-body textarea {
  padding: 4px 6px;
}

.topbar-category-body select,
.topbar-category-body input[type='number'],
.topbar-category-body input[type='text'] {
  min-height: 22px;
  padding: 0 5px;
}

.board-leftbar-layer .tool-button {
  max-width: 36px;
  justify-self: center;
}

.tool-button[data-tooltip]::after {
  left: calc(100% + 6px);
  padding: 4px 6px;
}

.toolbar-icon-button:disabled {
  opacity: 0.45;
}


.compact-field--presets {
  min-width: 184px;
  max-width: none;
  flex: 0 0 auto;
}

.color-preset-strip {
  display: flex;
  align-items: center;
  gap: 3px;
  min-width: max-content;
  max-width: none;
  flex-wrap: nowrap;
  overflow: visible;
}

.preset-chip-row {
  display: flex;
  align-items: center;
  gap: 2px;
  min-height: 20px;
  min-width: max-content;
  max-width: none;
  flex: 0 0 auto;
  flex-wrap: nowrap;
  overflow: visible;
  white-space: nowrap;
  scrollbar-width: auto;
}

.preset-chip-row::-webkit-scrollbar {
  height: 0;
}

.preset-chip-row::-webkit-scrollbar-thumb {
  background: transparent;
  border-radius: 999px;
}

.preset-mini-button {
  flex: 0 0 auto;
}

.preset-chip-item {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.preset-chip {
  width: 12px;
  height: 12px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,0.28);
  background: rgba(255,255,255,0.22);
  padding: 0;
  cursor: pointer;
  box-shadow: 0 0 0 1px rgba(0,0,0,0.18);
}

.preset-chip.is-active {
  box-shadow: 0 0 0 1px rgba(255,255,255,0.85), 0 0 0 2px rgba(59,130,246,0.85);
}

.preset-chip-remove {
  position: absolute;
  top: -5px;
  right: -5px;
  width: 12px;
  height: 12px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,0.25);
  background: rgba(127, 29, 29, 0.96);
  color: #fff;
  font-size: 9px;
  line-height: 1;
  padding: 0;
  display: none;
  cursor: pointer;
}

.color-preset-strip.is-editing .preset-chip-remove {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.color-preset-strip.is-editing .preset-chip {
  opacity: 0.7;
}

.preset-mini-button {
  min-width: 18px;
  width: 18px;
  height: 18px;
  border-radius: 999px;
  border: 1px solid rgba(148,163,184,0.28);
  background: rgba(0, 40, 24, 0.72);
  color: #fff;
  font-size: 11px;
  line-height: 1;
  padding: 0;
  cursor: pointer;
}

.preset-mini-button[hidden] {
  display: none !important;
}

.preset-mini-button.is-active,
.preset-mini-button--manage.is-active {
  background: rgba(30, 41, 59, 0.98);
  border-color: rgba(96, 165, 250, 0.8);
  color: #93c5fd;
}


.board-body.is-readonly {
  --board-safe-left: 0px;
}

.board-body.is-readonly .board-leftbar-layer {
  display: none;
}

.board-body.is-readonly .topbar-category-strip,
.board-body.is-readonly .topbar-category-body {
  visibility: hidden !important;
  pointer-events: none !important;
}

.board-body.is-readonly .board-topbar-content {
  grid-template-rows: auto minmax(0, 1fr);
  gap: 2px;
}

.board-body.is-readonly #deleteSelectedButton,
.board-body.is-readonly #copySelectionButton,
.board-body.is-readonly #pasteSelectionButton,
.board-body.is-readonly #copyImageClipboardButton,
.board-body.is-readonly #undoButton,
.board-body.is-readonly #redoButton,
.board-body.is-readonly #clearFixedProblemButton {
  display: none !important;
}

.board-body.is-readonly #boardInteractionCanvas {
  pointer-events: none;
}


/* ===== Blackboard mobile phase 1: PC layout isolation / swipe-tool split ===== */
@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  .board-body {
    --board-mobile-safe-bottom: calc(36px + env(safe-area-inset-bottom, 0px));
    --board-mobile-tool-dock-height: 98px;
    background: #002818;
    overflow: hidden;
  }

  .board-app {
    --board-mobile-safe-bottom: calc(36px + env(safe-area-inset-bottom, 0px));
    --board-mobile-tool-dock-height: 98px;
    --board-mobile-settings-height: min(56vh, 370px);
    --board-safe-left: 0px;
    --board-safe-top: 0px;
    --board-right-width: 0px;
    --fixed-problem-height: 62px;
    --fixed-problem-offset: var(--fixed-problem-height);
  }

  .board-logo-layer {
    display: none;
  }

  .board-mobile-controls {
    position: fixed;
    left: 8px;
    right: 8px;
    top: calc(8px + env(safe-area-inset-top, 0px));
    z-index: 80;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    pointer-events: none;
  }

  .board-mobile-mode-toggle,
  .board-mobile-menu-toggle {
    pointer-events: auto;
    min-height: 60px;
    border: 1px solid rgba(148, 184, 163, 0.28);
    border-radius: 999px;
    background: rgba(0, 0, 0, 0.52);
    color: #ffffff;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.28);
    -webkit-tap-highlight-color: transparent;
  }

  .board-mobile-mode-toggle {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    min-width: 166px;
    padding: 0 16px;
    font-size: 1.04rem;
    font-weight: 700;
    letter-spacing: 0.02em;
  }

  .board-mobile-mode-toggle__lamp {
    width: 18px;
    height: 18px;
    border-radius: 999px;
    background: rgba(148, 163, 184, 0.9);
    box-shadow: 0 0 0 3px rgba(148, 163, 184, 0.16);
  }

  .board-mobile-menu-toggle {
    display: grid;
    place-items: center;
    width: 54px;
    padding: 0;
    font-size: 1.58rem;
    line-height: 1;
  }

  .board-app.is-mobile-tool-mode .board-mobile-mode-toggle {
    background: rgba(0, 110, 72, 0.78);
    border-color: rgba(52, 211, 153, 0.7);
  }

  .board-app.is-mobile-tool-mode .board-mobile-mode-toggle__lamp {
    background: rgba(52, 211, 153, 1);
    box-shadow: 0 0 0 3px rgba(52, 211, 153, 0.18), 0 0 16px rgba(52, 211, 153, 0.88);
  }

  .board-app.is-mobile-swipe-mode .board-mobile-mode-toggle {
    background: rgba(0, 0, 0, 0.54);
  }

  .board-body.is-readonly .board-mobile-mode-toggle {
    display: none;
  }

  .board-workspace-layer {
    left: 0 !important;
    top: 0 !important;
    right: 0 !important;
    bottom: var(--board-mobile-safe-bottom) !important;
  }

  .fixed-problem-panel {
    display: block;
    top: 0;
    z-index: 20;
    height: var(--fixed-problem-height);
  }

  .fixed-problem-panel.is-collapsed {
    visibility: hidden;
    pointer-events: none;
  }

  .board-canvas-shell {
    top: 0 !important;
    bottom: 0 !important;
  }

  .board-canvas-scroll {
    overscroll-behavior: auto;
    touch-action: pan-x pan-y pinch-zoom;
  }

  /* Phase 7: スマホのツールモード中は、スクロール判定を親スクロール層でも止めます。 */
  /* 描画中の一筆がブラウザスクロールへ奪われ、別位置へ線が続く事故を防ぎます。 */
  .board-app.is-mobile-tool-mode .board-canvas-scroll,
  body.is-board-mobile-tool-mode .board-canvas-scroll {
    overscroll-behavior: contain !important;
    touch-action: none !important;
    -webkit-overflow-scrolling: auto !important;
  }

  body.is-board-mobile-drawing .board-canvas-scroll {
    overflow: hidden !important;
  }

  .board-app.is-mobile-swipe-mode #boardInteractionCanvas {
    pointer-events: none;
  }

  .board-app.is-mobile-tool-mode #boardInteractionCanvas {
    pointer-events: auto;
    touch-action: none;
  }

  .board-leftbar-layer {
    position: fixed !important;
    left: 8px !important;
    right: 8px !important;
    top: auto !important;
    bottom: calc(var(--board-mobile-safe-bottom) + 8px) !important;
    z-index: 72 !important;
    width: auto !important;
    height: var(--board-mobile-tool-dock-height) !important;
    padding: 9px !important;
    display: flex !important;
    align-items: center !important;
    gap: 10px !important;
    overflow-x: auto !important;
    overflow-y: visible !important;
    border: 1px solid rgba(148, 184, 163, 0.22) !important;
    border-radius: 22px !important;
    background: rgba(0, 0, 0, 0.80) !important;
    box-shadow: 0 18px 42px rgba(0, 0, 0, 0.34);
    transform: translateY(calc(100% + 18px));
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: transform 0.2s ease, opacity 0.2s ease, visibility 0.2s ease;
  }

  .board-app.is-mobile-tool-mode .board-leftbar-layer {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }

  .board-leftbar-layer .tool-button,
  .tool-button {
    flex: 0 0 74px;
    width: 74px !important;
    max-width: 74px !important;
    min-width: 74px !important;
    height: 74px !important;
    min-height: 74px !important;
    aspect-ratio: auto;
    border-radius: 18px;
    font-size: 1.22rem;
  }


  .board-leftbar-layer .tool-button span,
  .tool-button span {
    font-size: 0.78rem;
    line-height: 1.05;
  }


  .board-leftbar-layer .tool-button,
  .board-leftbar-layer .tool-group-toggle,
  .board-leftbar-layer .tool-button--subtool {
    touch-action: manipulation;
    user-select: none;
    -webkit-user-select: none;
    -webkit-touch-callout: none;
  }

  .tool-button[data-tooltip]::after,
  .toolbar-icon-button[data-tooltip]::after {
    display: none !important;
  }

  .tool-group {
    flex: 0 0 auto;
  }

  .tool-group-menu,
  .tool-group-menu.is-mobile-floating-tool-menu {
    position: fixed !important;
    left: 10px !important;
    right: 10px !important;
    top: auto !important;
    bottom: calc(var(--board-mobile-safe-bottom) + var(--board-mobile-tool-dock-height) + 18px) !important;
    z-index: 9994 !important;
    width: auto !important;
    max-width: none !important;
    grid-auto-flow: column !important;
    grid-auto-columns: 74px !important;
    justify-content: start;
    overflow-x: auto;
    overflow-y: visible;
    padding: 10px !important;
    border-radius: 20px !important;
    background: rgba(0, 0, 0, 0.94) !important;
    box-shadow: 0 18px 42px rgba(0, 0, 0, 0.42);
    touch-action: manipulation;
    -webkit-overflow-scrolling: touch;
  }

  .board-app.is-mobile-tool-mode .tool-group.is-open .tool-group-menu,
  .tool-group-menu.is-mobile-floating-tool-menu:not([hidden]) {
    display: grid !important;
    visibility: visible !important;
    opacity: 1 !important;
    pointer-events: auto !important;
  }

  .board-mobile-subtool-palette {
    position: fixed !important;
    left: 10px !important;
    right: 10px !important;
    bottom: calc(var(--board-mobile-safe-bottom) + var(--board-mobile-tool-dock-height) + 18px) !important;
    z-index: 9998 !important;
    display: grid;
    grid-auto-flow: column;
    grid-auto-columns: 74px;
    justify-content: start;
    gap: 10px;
    overflow-x: auto;
    overflow-y: visible;
    padding: 10px;
    border: 1px solid rgba(148, 184, 163, 0.24);
    border-radius: 22px;
    background: rgba(0, 0, 0, 0.94);
    box-shadow: 0 18px 44px rgba(0, 0, 0, 0.46);
    touch-action: manipulation;
    -webkit-overflow-scrolling: touch;
  }

  .board-mobile-subtool-palette[hidden] {
    display: none !important;
  }

  .board-mobile-subtool-palette__button {
    width: 74px !important;
    min-width: 74px !important;
    max-width: 74px !important;
    height: 74px !important;
    min-height: 74px !important;
    border-radius: 18px;
    font-size: 1.22rem;
    touch-action: manipulation;
    user-select: none;
    -webkit-user-select: none;
    -webkit-touch-callout: none;
  }

  .board-topbar-layer {
    position: fixed !important;
    left: 8px !important;
    right: 8px !important;
    top: auto !important;
    bottom: calc(var(--board-mobile-safe-bottom) + var(--board-mobile-tool-dock-height) + 16px) !important;
    z-index: 71 !important;
    height: var(--board-mobile-settings-height) !important;
    max-height: var(--board-mobile-settings-height) !important;
    border: 1px solid rgba(148, 184, 163, 0.22) !important;
    border-radius: 22px !important;
    background: rgba(0, 0, 0, 0.80) !important;
    box-shadow: 0 18px 42px rgba(0, 0, 0, 0.34);
    transform: translateY(calc(100% + var(--board-mobile-tool-dock-height) + 34px));
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: transform 0.2s ease, opacity 0.2s ease, visibility 0.2s ease;
  }

  .board-app.is-mobile-settings-open .board-topbar-layer {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }

  .topbar-spacer {
    display: none !important;
  }

  .board-topbar-content {
    margin-left: 0 !important;
    height: 100%;
    padding: 10px !important;
    overflow-x: auto;
    overflow-y: auto;
  }

  .topbar-toolbar-header {
    grid-template-columns: minmax(0, 1fr) auto;
  }

  .topbar-toolbar-actions {
    max-width: 46vw;
    overflow-x: auto;
    padding-bottom: 1px;
  }

  .toolbar-icon-button {
    min-width: 54px;
    width: 54px;
    height: 54px;
    font-size: 1rem;
  }

  .topbar-category-strip {
    min-width: 0;
    overflow-x: auto;
  }

  .topbar-category-body {
    overflow-x: auto !important;
    overflow-y: hidden !important;
    border-radius: 12px;
  }

  .toolbar-category-button {
    min-height: 46px;
    padding: 9px 16px;
    font-size: 0.96rem;
  }

  .topbar-tool-panel {
    gap: 10px;
    min-height: 54px;
  }

  .topbar-category-body .compact-field {
    gap: 7px;
    font-size: 0.9rem;
  }

  .topbar-category-body .compact-field span {
    font-size: 0.78rem;
  }

  .topbar-category-body .compact-field input[type='color'] {
    width: 56px;
    min-width: 56px;
    height: 50px;
  }

  .topbar-category-body .compact-field input[type='range'] {
    width: 156px;
    min-height: 46px;
  }

  .topbar-category-body .compact-field--select select,
  .topbar-category-body .compact-field--number input,
  .topbar-category-body .compact-field--mini input {
    width: 92px;
    min-height: 48px;
    font-size: 1.04rem;
  }

  .topbar-category-body .compact-check-field,
  .topbar-category-body .button--small.selection-metrics-apply {
    min-height: 48px;
    padding: 0 15px;
    font-size: 0.96rem;
  }

  .preset-chip {
    width: 32px;
    height: 32px;
  }

  .preset-mini-button {
    width: 42px;
    min-width: 42px;
    height: 42px;
    font-size: 1rem;
  }

  .topbar-tool-panel {
    min-width: max-content;
  }

  .board-rightbar-layer {
    display: flex !important;
    flex-direction: column;
    align-items: center;
    position: fixed !important;
    top: calc(62px + env(safe-area-inset-top, 0px)) !important;
    right: 8px !important;
    bottom: calc(var(--board-mobile-safe-bottom) + 8px) !important;
    left: auto !important;
    z-index: 75 !important;
    width: min(92vw, 300px) !important;
    height: auto !important;
    padding: 10px !important;
    gap: 10px;
    border: 1px solid rgba(148, 184, 163, 0.22) !important;
    border-radius: 22px !important;
    background: rgba(0, 0, 0, 0.90) !important;
    box-shadow: 0 18px 48px rgba(0, 0, 0, 0.42);
    transform: translateX(calc(100% + 18px)) !important;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    overflow: hidden !important;
    transition: transform 0.22s ease, opacity 0.22s ease, visibility 0.22s ease;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer {
    transform: translateX(0) !important;
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }

  .right-clock-slot {
    position: static !important;
    display: block !important;
    flex: 0 0 auto;
    align-self: center;
    width: min(100%, 260px) !important;
    max-width: 260px !important;
    height: auto !important;
    min-height: 0 !important;
    margin: 0 !important;
    padding: 0 !important;
    aspect-ratio: 1 / 1;
    border: 1px solid rgba(148, 184, 163, 0.18);
    border-radius: 18px;
    overflow: hidden;
    background: rgba(0, 18, 10, 0.82);
  }

  .right-clock-slot__frame {
    display: block !important;
    width: 100% !important;
    height: 100% !important;
    border: 0;
    transform: translateZ(0);
  }

  .board-side-toggle {
    display: none !important;
  }

  .right-status-panel {
    position: static !important;
    display: grid !important;
    grid-template-rows: auto minmax(0, 1fr);
    flex: 1 1 auto;
    align-self: center;
    min-height: 0;
    width: min(100%, 260px) !important;
    max-width: 260px !important;
    padding: 0 !important;
    border: 0 !important;
    border-radius: 0 !important;
    background: transparent !important;
    box-shadow: none !important;
    transform: translateX(0) !important;
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    overflow: hidden !important;
    transition: transform 0.2s ease, max-height 0.2s ease;
  }

  .right-status-panel:not(.is-open) {
    flex: 0 0 auto;
    grid-template-rows: auto;
    transform: translateX(calc(100% - 52px)) !important;
    min-height: 58px;
    max-height: 58px;
    overflow: visible !important;
  }

  .right-status-panel:not(.is-open) .right-status-panel__body {
    display: none !important;
  }

  .right-status-panel:not(.is-open) .right-status-panel__header {
    min-height: 42px;
  }

  .right-status-panel:not(.is-open) .right-status-panel__header h2,
  .right-status-panel:not(.is-open) .right-status-panel__header .status-pill {
    visibility: hidden;
  }

  .right-status-panel:not(.is-open) .right-status-panel__header-actions {
    justify-items: start;
    visibility: visible;
  }

  .right-status-panel:not(.is-open) .right-status-panel__close {
    justify-self: start;
  }

  .right-status-panel__body {
    min-height: 0;
    max-height: none;
    overflow-x: hidden !important;
    overflow-y: auto !important;
    padding-right: 4px;
    overscroll-behavior: contain;
    -webkit-overflow-scrolling: touch;
  }

  .right-status-panel__header h2 {
    font-size: 1.18rem;
  }

  .right-status-panel__close {
    min-width: 42px;
    min-height: 42px;
  }

  .board-app.is-mobile-right-menu-open .board-mobile-menu-toggle {
    background: rgba(0, 110, 72, 0.78);
    border-color: rgba(52, 211, 153, 0.7);
  }

  .board-zoom-panel {
    position: fixed !important;
    left: 8px !important;
    right: 8px !important;
    bottom: calc(6px + env(safe-area-inset-bottom, 0px)) !important;
    z-index: 78 !important;
    display: block !important;
    width: auto !important;
    padding: 3px 8px !important;
    border-radius: 999px !important;
    background: rgba(0, 0, 0, 0.62) !important;
    pointer-events: auto;
  }

  .board-zoom-panel__row {
    gap: 6px;
  }

  .board-zoom-panel__slider {
    flex: 1 1 auto;
    width: auto;
  }

  .board-zoom-panel__field input {
    width: 50px;
    height: 20px;
  }
}

@media (min-width: 768px) and (hover: hover) and (pointer: fine), (min-width: 1101px), (min-height: 1101px) {
  .board-mobile-controls {
    display: none !important;
  }
}

@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  /* Phase 7: スマホ右バーは外枠を固定し、時計と状態表示を別レイヤーで扱う。 */
  .board-rightbar-layer {
    display: block !important;
    overflow: hidden !important;
  }

  .board-rightbar-layer .right-clock-slot {
    position: absolute !important;
    top: 10px !important;
    left: 50% !important;
    right: auto !important;
    transform: translateX(-50%) !important;
    z-index: 2 !important;
    width: min(100%, 260px) !important;
    max-width: 260px !important;
    height: min(100%, 260px) !important;
    max-height: 260px !important;
    margin: 0 !important;
  }

  .board-rightbar-layer .right-status-panel {
    position: absolute !important;
    top: 280px !important;
    right: 10px !important;
    bottom: 10px !important;
    left: auto !important;
    z-index: 3 !important;
    width: min(calc(100% - 20px), 260px) !important;
    max-width: 260px !important;
    min-height: 0 !important;
    max-height: none !important;
    display: grid !important;
    grid-template-rows: auto minmax(0, 1fr) !important;
    padding: 0 !important;
    border: 0 !important;
    border-radius: 16px !important;
    background: rgba(0, 28, 18, 0.86) !important;
    box-shadow: none !important;
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
    overflow: hidden !important;
    transition: transform 0.2s ease !important;
  }

  .board-rightbar-layer .right-status-panel.is-open {
    transform: translateX(0) !important;
  }

  .board-rightbar-layer .right-status-panel:not(.is-open) {
    transform: translateX(calc(100% - 52px)) !important;
    min-height: 52px !important;
    max-height: none !important;
  }

  .board-rightbar-layer .right-status-panel:not(.is-open) .right-status-panel__body {
    display: none !important;
  }

  .board-rightbar-layer .right-status-panel:not(.is-open) .right-status-panel__header h2,
  .board-rightbar-layer .right-status-panel:not(.is-open) .right-status-panel__header .status-pill,
  .board-rightbar-layer .right-status-panel:not(.is-open) .board-status {
    visibility: hidden !important;
  }

  .board-rightbar-layer .right-status-panel__body {
    min-height: 0 !important;
    overflow-x: hidden !important;
    overflow-y: auto !important;
    overscroll-behavior: contain;
    -webkit-overflow-scrolling: touch;
  }

  /* Phase 7: 子ツールはPCの右横展開ではなく、スマホ下部ツールドックの上へ横並びで出す。 */
  .board-mobile-subtool-palette {
    top: auto !important;
    left: 10px !important;
    right: 10px !important;
    bottom: calc(154px + env(safe-area-inset-bottom, 0px)) !important;
    display: grid !important;
    grid-auto-flow: column !important;
    grid-auto-columns: 78px !important;
    grid-template-rows: 78px !important;
    align-items: center !important;
    justify-content: start !important;
    z-index: 10020 !important;
    visibility: visible !important;
    opacity: 1 !important;
    pointer-events: auto !important;
  }

  .board-mobile-subtool-palette[hidden] {
    display: none !important;
  }

  .board-mobile-subtool-palette__button {
    width: 78px !important;
    min-width: 78px !important;
    max-width: 78px !important;
    height: 78px !important;
    min-height: 78px !important;
  }
}

@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  /* Phase 8: スマホ右バーは時計行と状態行を固定グリッドにして、状態だけを右へ畳む。 */
  .board-app.is-mobile-right-menu-open .board-rightbar-layer {
    display: grid !important;
    grid-template-rows: minmax(0, 260px) minmax(0, 1fr) !important;
    align-items: stretch !important;
    justify-items: center !important;
    row-gap: 10px !important;
    overflow: hidden !important;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-clock-slot {
    position: relative !important;
    top: auto !important;
    right: auto !important;
    bottom: auto !important;
    left: auto !important;
    grid-row: 1 !important;
    align-self: start !important;
    justify-self: center !important;
    z-index: 2 !important;
    width: min(100%, 260px) !important;
    max-width: 260px !important;
    height: 260px !important;
    max-height: 260px !important;
    min-height: 0 !important;
    margin: 0 !important;
    transform: none !important;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel {
    position: relative !important;
    top: auto !important;
    right: auto !important;
    bottom: auto !important;
    left: auto !important;
    grid-row: 2 !important;
    align-self: stretch !important;
    justify-self: center !important;
    z-index: 3 !important;
    width: min(100%, 260px) !important;
    max-width: 260px !important;
    min-height: 0 !important;
    max-height: none !important;
    display: grid !important;
    grid-template-rows: auto minmax(0, 1fr) !important;
    overflow: hidden !important;
    transition: transform 0.2s ease !important;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel.is-open {
    transform: translateX(0) !important;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel:not(.is-open) {
    transform: translateX(calc(100% - 52px)) !important;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel__body {
    min-height: 0 !important;
    max-height: none !important;
    overflow-x: hidden !important;
    overflow-y: auto !important;
    overscroll-behavior: contain !important;
    -webkit-overflow-scrolling: touch;
  }

  /* Phase 8: 子アイコンは body 直下のスマホ専用パレットとして、下部ツールバーの上に横並びで出す。 */
  body > .board-mobile-subtool-palette,
  .board-mobile-subtool-palette.is-open:not([hidden]) {
    position: fixed !important;
    top: auto !important;
    left: 10px !important;
    right: 10px !important;
    bottom: calc(156px + env(safe-area-inset-bottom, 0px)) !important;
    z-index: 2147483000 !important;
    display: grid !important;
    grid-auto-flow: column !important;
    grid-auto-columns: 78px !important;
    grid-template-rows: 78px !important;
    align-items: center !important;
    justify-content: start !important;
    gap: 10px !important;
    padding: 10px !important;
    visibility: visible !important;
    opacity: 1 !important;
    pointer-events: auto !important;
    overflow-x: auto !important;
    overflow-y: visible !important;
    border: 1px solid rgba(148, 184, 163, 0.28) !important;
    border-radius: 22px !important;
    background: rgba(0, 0, 0, 0.96) !important;
    box-shadow: 0 18px 44px rgba(0, 0, 0, 0.58) !important;
    transform: none !important;
    -webkit-overflow-scrolling: touch;
  }

  body > .board-mobile-subtool-palette[hidden],
  .board-mobile-subtool-palette[hidden] {
    display: none !important;
  }

  body > .board-mobile-subtool-palette .board-mobile-subtool-palette__button,
  .board-mobile-subtool-palette.is-open .board-mobile-subtool-palette__button {
    width: 78px !important;
    min-width: 78px !important;
    max-width: 78px !important;
    height: 78px !important;
    min-height: 78px !important;
  }
}

/* ===== Blackboard mobile phase 9: visible subtool palette / compact collapsed status ===== */
@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  .board-body {
    --board-mobile-safe-bottom: calc(36px + env(safe-area-inset-bottom, 0px));
    --board-mobile-tool-dock-height: 98px;
  }

  body > .board-mobile-subtool-palette,
  body > .board-mobile-subtool-palette.is-open:not([hidden]),
  .board-mobile-subtool-palette.is-open:not([hidden]) {
    position: fixed !important;
    top: auto !important;
    left: 10px !important;
    right: 10px !important;
    bottom: calc(156px + env(safe-area-inset-bottom, 0px)) !important;
    z-index: 2147483000 !important;
    display: grid !important;
    grid-auto-flow: column !important;
    grid-auto-columns: 78px !important;
    grid-template-rows: 78px !important;
    align-items: center !important;
    justify-content: start !important;
    gap: 10px !important;
    padding: 10px !important;
    visibility: visible !important;
    opacity: 1 !important;
    pointer-events: auto !important;
    overflow-x: auto !important;
    overflow-y: visible !important;
    border: 1px solid rgba(148, 184, 163, 0.28) !important;
    border-radius: 22px !important;
    background: rgba(0, 0, 0, 0.96) !important;
    box-shadow: 0 18px 44px rgba(0, 0, 0, 0.58) !important;
    transform: none !important;
    -webkit-overflow-scrolling: touch;
  }

  body > .board-mobile-subtool-palette[hidden],
  .board-mobile-subtool-palette[hidden] {
    display: none !important;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel:not(.is-open) {
    width: 52px !important;
    max-width: 52px !important;
    height: 52px !important;
    min-height: 52px !important;
    max-height: 52px !important;
    align-self: start !important;
    justify-self: end !important;
    transform: none !important;
    border-radius: 14px !important;
    background: rgba(0, 34, 22, 0.84) !important;
    overflow: hidden !important;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel:not(.is-open) .right-status-panel__header {
    display: grid !important;
    grid-template-columns: 1fr !important;
    align-items: center !important;
    justify-items: center !important;
    width: 52px !important;
    height: 52px !important;
    min-height: 52px !important;
    padding: 0 !important;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel:not(.is-open) .right-status-panel__header-actions {
    display: grid !important;
    align-items: center !important;
    justify-items: center !important;
    width: 52px !important;
    height: 52px !important;
    visibility: visible !important;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel:not(.is-open) .right-status-panel__close {
    width: 40px !important;
    min-width: 40px !important;
    height: 40px !important;
    min-height: 40px !important;
    justify-self: center !important;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel:not(.is-open) .right-status-panel__body,
  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel:not(.is-open) .right-status-panel__header h2,
  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel:not(.is-open) .right-status-panel__header .status-pill,
  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel:not(.is-open) .board-status {
    display: none !important;
    visibility: hidden !important;
  }
}


/* ===== Blackboard mobile phase 10: softer HUD opacity / visual viewport fixed controls ===== */
@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  :root,
  body {
    --board-mobile-vv-left: 0px;
    --board-mobile-vv-top: 0px;
    --board-mobile-vv-width: 100vw;
    --board-mobile-vv-height: 100vh;
    --board-mobile-vv-inverse-scale: 1;
  }

  .board-mobile-controls {
    left: calc(var(--board-mobile-vv-left, 0px) + 8px) !important;
    right: auto !important;
    top: calc(var(--board-mobile-vv-top, 0px) + 8px + env(safe-area-inset-top, 0px)) !important;
    width: calc(var(--board-mobile-vv-width, 100vw) - 16px) !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    will-change: left, top, transform;
  }

  .board-mobile-mode-toggle,
  .board-mobile-menu-toggle {
    background: rgba(0, 0, 0, 0.38) !important;
    border-color: rgba(148, 184, 163, 0.22) !important;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.22) !important;
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
  }

  .board-app.is-mobile-swipe-mode .board-mobile-mode-toggle {
    background: rgba(0, 0, 0, 0.40) !important;
  }

  .board-app.is-mobile-tool-mode .board-mobile-mode-toggle,
  .board-app.is-mobile-right-menu-open .board-mobile-menu-toggle {
    background: rgba(0, 110, 72, 0.64) !important;
    border-color: rgba(52, 211, 153, 0.58) !important;
  }

  .board-leftbar-layer {
    left: calc(var(--board-mobile-vv-left, 0px) + 8px) !important;
    right: auto !important;
    top: calc(var(--board-mobile-vv-top, 0px) + var(--board-mobile-vv-height, 100vh) - var(--board-mobile-tool-dock-height, 98px) - var(--board-mobile-safe-bottom, 36px) - 8px) !important;
    bottom: auto !important;
    width: calc(var(--board-mobile-vv-width, 100vw) - 16px) !important;
    background: rgba(0, 0, 0, 0.66) !important;
    border-color: rgba(148, 184, 163, 0.18) !important;
    box-shadow: 0 16px 38px rgba(0, 0, 0, 0.28) !important;
    transform: translateY(calc(100% + 18px)) scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    will-change: left, top, transform;
  }

  .board-app.is-mobile-tool-mode .board-leftbar-layer {
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
  }

  .board-zoom-panel {
    left: calc(var(--board-mobile-vv-left, 0px) + 8px) !important;
    right: auto !important;
    top: calc(var(--board-mobile-vv-top, 0px) + var(--board-mobile-vv-height, 100vh) - 34px - env(safe-area-inset-bottom, 0px)) !important;
    bottom: auto !important;
    width: calc(var(--board-mobile-vv-width, 100vw) - 16px) !important;
    background: rgba(0, 0, 0, 0.48) !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    will-change: left, top, transform;
  }

  body > .board-mobile-subtool-palette,
  body > .board-mobile-subtool-palette.is-open:not([hidden]),
  .board-mobile-subtool-palette.is-open:not([hidden]) {
    left: calc(var(--board-mobile-vv-left, 0px) + 10px) !important;
    right: auto !important;
    top: calc(var(--board-mobile-vv-top, 0px) + var(--board-mobile-vv-height, 100vh) - 254px - env(safe-area-inset-bottom, 0px)) !important;
    bottom: auto !important;
    width: calc(var(--board-mobile-vv-width, 100vw) - 20px) !important;
    background: rgba(0, 0, 0, 0.84) !important;
    border-color: rgba(148, 184, 163, 0.22) !important;
    box-shadow: 0 18px 44px rgba(0, 0, 0, 0.42) !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    will-change: left, top, transform;
  }

  .board-rightbar-layer {
    left: calc(var(--board-mobile-vv-left, 0px) + var(--board-mobile-vv-width, 100vw) - min(calc(var(--board-mobile-vv-width, 100vw) - 16px), 300px) - 8px) !important;
    right: auto !important;
    top: calc(var(--board-mobile-vv-top, 0px) + 62px + env(safe-area-inset-top, 0px)) !important;
    bottom: auto !important;
    width: min(calc(var(--board-mobile-vv-width, 100vw) - 16px), 300px) !important;
    height: calc(var(--board-mobile-vv-height, 100vh) - 98px - env(safe-area-inset-bottom, 0px)) !important;
    background: rgba(0, 0, 0, 0.78) !important;
    transform: translateX(calc(100% + 18px)) scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    will-change: left, top, transform;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer {
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel:not(.is-open) {
    width: 52px !important;
    max-width: 52px !important;
    min-width: 52px !important;
    justify-self: end !important;
    align-self: start !important;
    transform: none !important;
    background: transparent !important;
    border: 0 !important;
    box-shadow: none !important;
    overflow: visible !important;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer .right-status-panel:not(.is-open) .right-status-panel__header {
    width: 52px !important;
    height: 52px !important;
    min-height: 52px !important;
    padding: 0 !important;
    border: 1px solid rgba(148, 184, 163, 0.22) !important;
    border-radius: 14px !important;
    background: rgba(0, 34, 22, 0.64) !important;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.24) !important;
  }
}


/* ===== Blackboard mobile phase 11: zoom-stable HUD / mobile undo redo / zoom under tools ===== */
@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  :root,
  body {
    --board-mobile-hud-left: 8px;
    --board-mobile-hud-top: 8px;
    --board-mobile-hud-width: calc(100vw - 16px);
    --board-mobile-dock-left: 8px;
    --board-mobile-dock-top: calc(100vh - 172px);
    --board-mobile-dock-width: calc(100vw - 16px);
    --board-mobile-zoom-left: 8px;
    --board-mobile-zoom-top: calc(100vh - 70px);
    --board-mobile-zoom-width: calc(100vw - 16px);
    --board-mobile-subtool-left: 10px;
    --board-mobile-subtool-top: calc(100vh - 270px);
    --board-mobile-subtool-width: calc(100vw - 20px);
    --board-mobile-rightbar-left: calc(100vw - 308px);
    --board-mobile-rightbar-top: 62px;
    --board-mobile-rightbar-width: min(calc(100vw - 16px), 300px);
    --board-mobile-rightbar-height: calc(100vh - 106px);
    --board-mobile-vv-inverse-scale: 1;
  }

  .board-mobile-controls {
    left: var(--board-mobile-hud-left) !important;
    top: var(--board-mobile-hud-top) !important;
    right: auto !important;
    width: var(--board-mobile-hud-width) !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    align-items: center !important;
    justify-content: space-between !important;
    pointer-events: none !important;
    will-change: left, top, transform;
  }

  .board-mobile-control-main {
    display: inline-flex !important;
    align-items: center !important;
    gap: 8px !important;
    min-width: 0 !important;
    pointer-events: auto !important;
  }

  .board-mobile-mode-toggle {
    min-width: 128px !important;
    width: 128px !important;
    min-height: 54px !important;
    height: 54px !important;
    padding: 0 13px !important;
    gap: 7px !important;
  }

  .board-mobile-mode-toggle__lamp {
    width: 16px !important;
    height: 16px !important;
    flex: 0 0 16px !important;
  }

  .board-mobile-mode-toggle__text {
    font-size: 0.96rem !important;
    white-space: nowrap !important;
  }

  .board-mobile-history-button,
  .board-mobile-menu-toggle {
    display: grid !important;
    place-items: center !important;
    width: 54px !important;
    min-width: 54px !important;
    max-width: 54px !important;
    height: 54px !important;
    min-height: 54px !important;
    max-height: 54px !important;
    padding: 0 !important;
    border: 1px solid rgba(148, 184, 163, 0.22) !important;
    border-radius: 999px !important;
    background: rgba(0, 0, 0, 0.36) !important;
    color: #ffffff !important;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.22) !important;
    font-size: 1.5rem !important;
    font-weight: 700 !important;
    line-height: 1 !important;
    pointer-events: auto !important;
    touch-action: manipulation !important;
    user-select: none !important;
    -webkit-user-select: none !important;
    -webkit-tap-highlight-color: transparent !important;
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
  }

  .board-mobile-history-button:disabled,
  .board-mobile-history-button[aria-disabled='true'] {
    opacity: 0.36 !important;
    filter: grayscale(0.4);
  }

  .board-app.is-mobile-tool-mode .board-mobile-mode-toggle,
  .board-app.is-mobile-right-menu-open .board-mobile-menu-toggle {
    background: rgba(0, 110, 72, 0.60) !important;
  }

  .board-leftbar-layer {
    left: var(--board-mobile-dock-left) !important;
    top: var(--board-mobile-dock-top) !important;
    right: auto !important;
    bottom: auto !important;
    width: var(--board-mobile-dock-width) !important;
    transform: translateY(calc(100% + 18px)) scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    background: rgba(0, 0, 0, 0.58) !important;
    will-change: left, top, transform;
  }

  .board-app.is-mobile-tool-mode .board-leftbar-layer {
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
  }

  .board-zoom-panel {
    left: var(--board-mobile-zoom-left) !important;
    top: var(--board-mobile-zoom-top) !important;
    right: auto !important;
    bottom: auto !important;
    width: var(--board-mobile-zoom-width) !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    background: rgba(0, 0, 0, 0.42) !important;
    will-change: left, top, transform;
  }

  body > .board-mobile-subtool-palette,
  body > .board-mobile-subtool-palette.is-open:not([hidden]),
  .board-mobile-subtool-palette.is-open:not([hidden]) {
    left: var(--board-mobile-subtool-left) !important;
    top: var(--board-mobile-subtool-top) !important;
    right: auto !important;
    bottom: auto !important;
    width: var(--board-mobile-subtool-width) !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    background: rgba(0, 0, 0, 0.82) !important;
    will-change: left, top, transform;
  }

  .board-rightbar-layer {
    left: var(--board-mobile-rightbar-left) !important;
    top: var(--board-mobile-rightbar-top) !important;
    right: auto !important;
    bottom: auto !important;
    width: var(--board-mobile-rightbar-width) !important;
    height: var(--board-mobile-rightbar-height) !important;
    transform: translateX(calc(100% + 18px)) scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    background: rgba(0, 0, 0, 0.70) !important;
    will-change: left, top, transform;
  }

  .board-app.is-mobile-right-menu-open .board-rightbar-layer {
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
  }
}


/* ===== Blackboard mobile phase 12: stable mobile history buttons / zoom panel / topbar popup ===== */
@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  .board-mobile-controls {
    z-index: 2147482600 !important;
  }

  .board-mobile-control-main {
    display: inline-flex !important;
    align-items: center !important;
    gap: 7px !important;
    max-width: calc(100% - 62px) !important;
    pointer-events: auto !important;
  }

  .board-mobile-mode-toggle {
    min-width: 118px !important;
    width: 118px !important;
    max-width: 118px !important;
  }

  .board-mobile-history-button {
    display: grid !important;
    place-items: center !important;
    flex: 0 0 52px !important;
    width: 52px !important;
    min-width: 52px !important;
    max-width: 52px !important;
    height: 52px !important;
    min-height: 52px !important;
    max-height: 52px !important;
    padding: 0 !important;
    border: 1px solid rgba(148, 184, 163, 0.20) !important;
    border-radius: 999px !important;
    background: rgba(0, 0, 0, 0.34) !important;
    color: rgba(255, 255, 255, 0.95) !important;
    box-shadow: 0 8px 22px rgba(0, 0, 0, 0.22) !important;
    font-size: 1.44rem !important;
    font-weight: 800 !important;
    line-height: 1 !important;
    pointer-events: auto !important;
    touch-action: manipulation !important;
    user-select: none !important;
    -webkit-user-select: none !important;
    -webkit-tap-highlight-color: transparent !important;
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
  }

  .board-mobile-history-button:disabled,
  .board-mobile-history-button[aria-disabled='true'] {
    opacity: 0.34 !important;
    filter: grayscale(0.45);
  }

  .board-zoom-panel {
    position: fixed !important;
    left: var(--board-mobile-dock-left, 8px) !important;
    top: calc(var(--board-mobile-dock-top, calc(100vh - 172px)) + var(--board-mobile-tool-dock-height, 98px) + 4px) !important;
    right: auto !important;
    bottom: auto !important;
    width: var(--board-mobile-dock-width, calc(100vw - 16px)) !important;
    height: 34px !important;
    min-height: 34px !important;
    max-height: 34px !important;
    padding: 4px 9px !important;
    z-index: 2147482500 !important;
    display: block !important;
    border: 1px solid rgba(148, 184, 163, 0.18) !important;
    border-radius: 999px !important;
    background: rgba(0, 0, 0, 0.38) !important;
    box-shadow: 0 8px 22px rgba(0, 0, 0, 0.22) !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    pointer-events: auto !important;
    will-change: left, top, transform;
  }

  .board-zoom-panel__row {
    height: 100% !important;
    gap: 8px !important;
    align-items: center !important;
  }

  .board-zoom-panel__field {
    flex: 0 0 auto !important;
    min-width: 56px !important;
    font-size: 0.84rem !important;
  }

  .board-zoom-panel__field input {
    width: 52px !important;
    height: 22px !important;
    min-height: 22px !important;
    font-size: 0.82rem !important;
  }

  .board-zoom-panel__slider {
    flex: 1 1 auto !important;
    width: auto !important;
    min-width: 120px !important;
  }

  .board-topbar-layer {
    position: fixed !important;
    left: var(--board-mobile-hud-left, 8px) !important;
    top: max(
      calc(var(--board-mobile-hud-top, 8px) + 68px),
      calc(var(--board-mobile-dock-top, calc(100vh - 172px)) - var(--board-mobile-settings-height, min(56vh, 370px)) - 14px)
    ) !important;
    right: auto !important;
    bottom: auto !important;
    width: var(--board-mobile-hud-width, calc(100vw - 16px)) !important;
    height: var(--board-mobile-settings-height, min(56vh, 370px)) !important;
    max-height: var(--board-mobile-settings-height, min(56vh, 370px)) !important;
    transform: translateY(18px) scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    z-index: 2147482400 !important;
    overflow: auto !important;
    -webkit-overflow-scrolling: touch;
    will-change: left, top, transform;
  }

  .board-app.is-mobile-settings-open .board-topbar-layer {
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
  }
}

/* ===== Blackboard mobile phase 13: body-level zoom slider below tool dock ===== */
@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  /* PC右バー内の既存ズームUIは残しつつ、スマホでは body 直下の追加スライダーを使う。 */
  .board-rightbar-layer > .board-zoom-panel {
    display: none !important;
  }

  .board-mobile-zoom-panel {
    position: fixed !important;
    left: var(--board-mobile-dock-left, 8px) !important;
    top: calc(var(--board-mobile-dock-top, calc(100vh - 172px)) + var(--board-mobile-tool-dock-height, 98px) + 5px) !important;
    right: auto !important;
    bottom: auto !important;
    z-index: 2147482700 !important;
    display: grid !important;
    grid-template-columns: auto minmax(120px, 1fr) !important;
    align-items: center !important;
    gap: 8px !important;
    width: var(--board-mobile-dock-width, calc(100vw - 16px)) !important;
    height: 38px !important;
    min-height: 38px !important;
    max-height: 38px !important;
    padding: 5px 10px !important;
    border: 1px solid rgba(148, 184, 163, 0.18) !important;
    border-radius: 999px !important;
    background: rgba(0, 0, 0, 0.42) !important;
    box-shadow: 0 8px 22px rgba(0, 0, 0, 0.22) !important;
    color: rgba(255, 255, 255, 0.96) !important;
    pointer-events: auto !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    transition: none !important;
    will-change: left, top, transform;
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
  }

  body:not(.is-board-mobile-tool-mode) .board-mobile-zoom-panel {
    display: none !important;
  }

  .board-mobile-zoom-panel__percent {
    min-width: 54px !important;
    font-size: 0.86rem !important;
    font-weight: 700 !important;
    line-height: 1 !important;
    text-align: right !important;
    white-space: nowrap !important;
  }

  .board-mobile-zoom-panel__slider {
    width: 100% !important;
    min-width: 120px !important;
    height: 26px !important;
    margin: 0 !important;
    accent-color: rgba(52, 211, 153, 0.9);
    touch-action: pan-x !important;
  }

  .board-mobile-controls,
  .board-leftbar-layer,
  .board-mobile-subtool-palette,
  .board-rightbar-layer,
  .board-topbar-layer {
    transition: none !important;
  }
}

@media (min-width: 768px) and (hover: hover) and (pointer: fine), (min-width: 1101px), (min-height: 1101px) {
  .board-mobile-zoom-panel {
    display: none !important;
  }
}

/* ===== Blackboard mobile phase 14: reliable zoom HUD and mobile portrait page expansion ===== */
@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  .board-mobile-zoom-panel {
    left: var(--board-mobile-zoom-left, 8px) !important;
    top: var(--board-mobile-zoom-top, calc(100vh - 64px)) !important;
    width: var(--board-mobile-zoom-width, calc(100vw - 16px)) !important;
    height: 42px !important;
    min-height: 42px !important;
    max-height: 42px !important;
    padding: 6px 10px !important;
    z-index: 2147482800 !important;
  }

  body.is-board-mobile-tool-mode .board-mobile-zoom-panel {
    display: grid !important;
  }

  .board-mobile-zoom-panel__percent {
    display: grid !important;
    place-items: center !important;
    min-width: 76px !important;
    width: 76px !important;
    height: 30px !important;
    min-height: 30px !important;
    padding: 0 10px !important;
    border: 1px solid rgba(148, 184, 163, 0.20) !important;
    border-radius: 999px !important;
    background: rgba(0, 0, 0, 0.36) !important;
    color: rgba(255, 255, 255, 0.96) !important;
    font-size: 0.9rem !important;
    font-weight: 800 !important;
    line-height: 1 !important;
    text-align: center !important;
    touch-action: manipulation !important;
    cursor: pointer !important;
    -webkit-tap-highlight-color: transparent !important;
  }

  .board-mobile-zoom-panel__slider {
    height: 30px !important;
    min-height: 30px !important;
  }
}



/* ===== Blackboard mobile dashboard return link ===== */
.mobile-dashboard-return-link {
  display: none;
}

@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  .mobile-dashboard-return-link {
    display: flex !important;
    align-items: center;
    justify-content: center;
    min-height: 42px;
    margin: 0 0 10px;
    padding: 10px 12px;
    border: 1px solid rgba(52, 211, 153, 0.34);
    border-radius: 14px;
    background: rgba(0, 110, 72, 0.52);
    color: rgba(255, 255, 255, 0.96);
    font-size: 0.98rem;
    font-weight: 800;
    letter-spacing: 0.02em;
    box-shadow: 0 10px 24px rgba(0, 0, 0, 0.24);
    -webkit-tap-highlight-color: transparent;
  }

  .mobile-dashboard-return-link:active {
    transform: translateY(1px);
    background: rgba(0, 140, 92, 0.62);
  }
}


/* ===== Blackboard mobile phase 16: drawable border and viewport clamp visual support ===== */
@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  /* 黒板そのものの境界だけを示す線です。土台レイヤーではなく、描画範囲である zoom-layer にだけ重ねます。 */
  .board-canvas-zoom-layer::after {
    content: "";
    position: absolute;
    inset: 0;
    z-index: 4;
    box-sizing: border-box;
    border: 3px solid rgba(52, 211, 153, 0.72);
    border-radius: 0;
    box-shadow:
      inset 0 0 0 1px rgba(255, 255, 255, 0.16),
      0 0 14px rgba(52, 211, 153, 0.28);
    pointer-events: none;
  }

  /* 生徒のスマホ表示では、固定領域表示アイコンをツールUIから外します。 */
  .board-body[data-user-role="student"] #toggleFixedProblemButton,
  .board-app[data-user-role="student"] #toggleFixedProblemButton {
    display: none !important;
  }
}


/* ===== Blackboard mobile landscape phase 1: horizontal smartphone only layout ===== */
@media (pointer: coarse) and (orientation: landscape) and (max-height: 520px) {
  /* 横向きスマホだけをスマホ黒板として扱うための土台です。PC幅の通常表示には触れません。 */
  .board-body {
    --board-mobile-safe-bottom: calc(36px + env(safe-area-inset-bottom, 0px));
    --board-mobile-tool-dock-height: 98px;
    background: #002818;
    overflow: hidden;
  }




  /* 横向きスマホだけ、PCの安全余白と右バー幅をいったん無効化します。 */
  .board-app {
    --board-mobile-safe-bottom: calc(36px + env(safe-area-inset-bottom, 0px));
    --board-mobile-tool-dock-height: 98px;
    --board-mobile-settings-height: min(64vh, 250px);
    --board-safe-left: 0px;
    --board-safe-top: 0px;
    --board-right-width: 0px;
    --fixed-problem-height: 62px;
    --fixed-problem-offset: var(--fixed-problem-height);
  }




  /* 横向きスマホではPC用ロゴだけ退避します。固定領域は講師側の表示状態に連動して表示します。 */
  .board-logo-layer {
    display: none !important;
  }

  .fixed-problem-panel {
    display: block;
    top: 0;
    z-index: 20;
    height: var(--fixed-problem-height);
  }

  .fixed-problem-panel.is-collapsed {
    visibility: hidden;
    pointer-events: none;
  }




  /* 横向きスマホではPC上バー・左バー・右バーによる黒板圧迫をなくします。 */
  .board-workspace-layer {
    left: 0 !important;
    top: 0 !important;
    right: 0 !important;
    bottom: var(--board-mobile-safe-bottom) !important;
  }




  /* 黒板スクロール本体では、スワイプモード時の移動とピンチズームを優先します。 */
  .board-canvas-shell {
    top: 0 !important;
    bottom: 0 !important;
  }




  .board-canvas-scroll {
    overscroll-behavior: auto;
    touch-action: pan-x pan-y pinch-zoom;
  }




  /* Phase 7: 横向きスマホのツールモード中は、親スクロール層でもスクロール判定を止めます。 */
  /* PC表示には当たらない media query 内だけの指定です。 */
  .board-app.is-mobile-tool-mode .board-canvas-scroll,
  body.is-board-mobile-tool-mode .board-canvas-scroll {
    overscroll-behavior: contain !important;
    touch-action: none !important;
    -webkit-overflow-scrolling: auto !important;
  }




  body.is-board-mobile-drawing .board-canvas-scroll {
    overflow: hidden !important;
  }




  /* スワイプモードでは描画イベントを黒板へ通さず、閲覧操作を優先します。 */
  .board-app.is-mobile-swipe-mode #boardInteractionCanvas {
    pointer-events: none;
  }




  /* ツールモードでは描画イベントを許可します。 */
  .board-app.is-mobile-tool-mode #boardInteractionCanvas {
    pointer-events: auto;
    touch-action: none;
  }




  /* 左上にモード切替、undo、redoを固定します。 */
  .board-mobile-controls {
    position: fixed !important;
    left: var(--board-mobile-hud-left, 8px) !important;
    top: var(--board-mobile-hud-top, 8px) !important;
    right: auto !important;
    width: var(--board-mobile-hud-width, calc(100vw - 16px)) !important;
    z-index: 2147482600 !important;
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    gap: 8px !important;
    pointer-events: none !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
  }




  .board-mobile-control-main {
    display: inline-flex !important;
    align-items: center !important;
    gap: 7px !important;
    max-width: calc(100% - 62px) !important;
    pointer-events: auto !important;
  }




  .board-mobile-mode-toggle,
  .board-mobile-menu-toggle,
  .board-mobile-history-button {
    pointer-events: auto !important;
    min-height: 52px !important;
    border: 1px solid rgba(148, 184, 163, 0.22) !important;
    border-radius: 999px !important;
    background: rgba(0, 0, 0, 0.38) !important;
    color: #ffffff !important;
    box-shadow: 0 8px 22px rgba(0, 0, 0, 0.22) !important;
    touch-action: manipulation !important;
    user-select: none !important;
    -webkit-user-select: none !important;
    -webkit-tap-highlight-color: transparent !important;
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
  }




  .board-mobile-mode-toggle {
    display: inline-flex !important;
    align-items: center !important;
    gap: 8px !important;
    width: 118px !important;
    min-width: 118px !important;
    max-width: 118px !important;
    padding: 0 12px !important;
    font-size: 0.98rem !important;
    font-weight: 700 !important;
  }




  .board-mobile-mode-toggle__lamp {
    width: 16px !important;
    height: 16px !important;
    border-radius: 999px !important;
    background: rgba(148, 163, 184, 0.9);
    box-shadow: 0 0 0 3px rgba(148, 163, 184, 0.16);
  }




  .board-mobile-history-button,
  .board-mobile-menu-toggle {
    display: grid !important;
    place-items: center !important;
    flex: 0 0 52px !important;
    width: 52px !important;
    min-width: 52px !important;
    max-width: 52px !important;
    height: 52px !important;
    min-height: 52px !important;
    max-height: 52px !important;
    padding: 0 !important;
    font-size: 1.38rem !important;
    font-weight: 800 !important;
    line-height: 1 !important;
  }




  .board-app.is-mobile-tool-mode .board-mobile-mode-toggle,
  .board-app.is-mobile-right-menu-open .board-mobile-menu-toggle {
    background: rgba(0, 110, 72, 0.74) !important;
    border-color: rgba(52, 211, 153, 0.62) !important;
  }




  .board-app.is-mobile-tool-mode .board-mobile-mode-toggle__lamp {
    background: rgba(52, 211, 153, 1);
    box-shadow: 0 0 0 3px rgba(52, 211, 153, 0.18), 0 0 16px rgba(52, 211, 153, 0.88);
  }




  .board-body.is-readonly .board-mobile-mode-toggle {
    display: none !important;
  }




  /* 横向きスマホでは、PC左バー相当を左端の縦ツールドックとして出します。 */
  .board-leftbar-layer {
    position: fixed !important;
    left: var(--board-mobile-dock-left, 8px) !important;
    top: var(--board-mobile-dock-top, 78px) !important;
    right: auto !important;
    bottom: auto !important;
    z-index: 2147482500 !important;
    width: var(--board-mobile-dock-width, 86px) !important;
    height: var(--board-mobile-dock-height, calc(100vh - 150px)) !important;
    padding: 8px !important;
    display: flex !important;
    flex-direction: column !important;
    align-items: center !important;
    gap: 8px !important;
    overflow-x: hidden !important;
    overflow-y: auto !important;
    border: 1px solid rgba(148, 184, 163, 0.20) !important;
    border-radius: 22px !important;
    background: rgba(0, 0, 0, 0.58) !important;
    box-shadow: 0 18px 42px rgba(0, 0, 0, 0.34);
    transform: translateX(calc(-100% - 18px)) scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: none !important;
    will-change: left, top, transform;
    -webkit-overflow-scrolling: touch;
  }




  .board-app.is-mobile-tool-mode .board-leftbar-layer {
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }




  .board-leftbar-layer .tool-group,
  .board-leftbar-layer .tool-button {
    flex: 0 0 auto !important;
  }




  .board-leftbar-layer .tool-button,
  .tool-button {
    width: 66px !important;
    min-width: 66px !important;
    max-width: 66px !important;
    height: 66px !important;
    min-height: 66px !important;
    border-radius: 18px !important;
    font-size: 1.12rem !important;
    touch-action: manipulation !important;
    user-select: none !important;
    -webkit-user-select: none !important;
    -webkit-touch-callout: none !important;
  }




  .board-leftbar-layer .tool-button span,
  .tool-button span {
    font-size: 0.72rem !important;
    line-height: 1.05 !important;
  }




  .tool-button[data-tooltip]::after,
  .toolbar-icon-button[data-tooltip]::after {
    display: none !important;
  }




  /* 子ツールは左ツールドックの右横へ横スクロール型で出します。 */
  body > .board-mobile-subtool-palette,
  body > .board-mobile-subtool-palette.is-open:not([hidden]),
  .board-mobile-subtool-palette.is-open:not([hidden]) {
    position: fixed !important;
    left: var(--board-mobile-subtool-left, 104px) !important;
    top: var(--board-mobile-subtool-top, 78px) !important;
    right: auto !important;
    bottom: auto !important;
    z-index: 2147483000 !important;
    display: grid !important;
    grid-auto-flow: column !important;
    grid-auto-columns: 78px !important;
    grid-template-rows: 78px !important;
    justify-content: start !important;
    gap: 10px !important;
    width: var(--board-mobile-subtool-width, calc(100vw - 120px)) !important;
    padding: 10px !important;
    overflow-x: auto !important;
    overflow-y: visible !important;
    border: 1px solid rgba(148, 184, 163, 0.24) !important;
    border-radius: 22px !important;
    background: rgba(0, 0, 0, 0.82) !important;
    box-shadow: 0 18px 44px rgba(0, 0, 0, 0.46);
    pointer-events: auto !important;
    touch-action: manipulation !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    -webkit-overflow-scrolling: touch;
  }




  body > .board-mobile-subtool-palette[hidden],
  .board-mobile-subtool-palette[hidden] {
    display: none !important;
  }




  .board-mobile-subtool-palette__button {
    width: 74px !important;
    min-width: 74px !important;
    max-width: 74px !important;
    height: 74px !important;
    min-height: 74px !important;
    border-radius: 18px !important;
  }




  /* PC上バー相当の設定は、最終ツール長押し時だけ横長ポップアップとして出します。 */
  .board-topbar-layer {
    position: fixed !important;
    left: var(--board-mobile-settings-left, 104px) !important;
    top: var(--board-mobile-settings-top, 62px) !important;
    right: auto !important;
    bottom: auto !important;
    z-index: 2147483150 !important;
    width: var(--board-mobile-settings-width, calc(100vw - 112px)) !important;
    height: var(--board-mobile-settings-height-landscape, 220px) !important;
    max-height: var(--board-mobile-settings-height-landscape, 220px) !important;
    border: 1px solid rgba(148, 184, 163, 0.22) !important;
    border-radius: 22px !important;
    background: rgba(0, 0, 0, 0.80) !important;
    box-shadow: 0 18px 42px rgba(0, 0, 0, 0.34);
    transform: translateY(18px) scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    overflow: auto !important;
    overscroll-behavior: contain !important;
    touch-action: pan-x pan-y !important;
    transition: none !important;
    will-change: left, top, transform;
    -webkit-overflow-scrolling: touch;
  }




  .board-app.is-mobile-settings-open .board-topbar-layer {
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }




  .board-topbar-content {
    margin-left: 0 !important;
    height: 100%;
    padding: 10px !important;
    overflow-x: auto !important;
    overflow-y: auto !important;
    overscroll-behavior: contain !important;
    touch-action: pan-x pan-y !important;
  }




  .topbar-spacer {
    display: none !important;
  }




  .topbar-toolbar-header,
  .topbar-category-strip,
  .topbar-category-body,
  .topbar-tool-panel {
    min-width: max-content !important;
  }




  .toolbar-icon-button {
    min-width: 52px !important;
    width: 52px !important;
    height: 52px !important;
    font-size: 1rem !important;
  }




  .toolbar-category-button {
    min-height: 44px !important;
    padding: 8px 14px !important;
    font-size: 0.94rem !important;
  }




  .topbar-category-body .compact-field input[type='range'] {
    width: 148px !important;
    min-height: 44px !important;
  }




  .topbar-category-body .compact-field--select select,
  .topbar-category-body .compact-field--number input,
  .topbar-category-body .compact-field--mini input {
    width: 92px !important;
    min-height: 46px !important;
    font-size: 1rem !important;
  }




  /* 右バーはハンバーガーから開き、横長スマホに合わせて時計と状態表示を横並びにします。 */
  .board-rightbar-layer {
    position: fixed !important;
    left: var(--board-mobile-rightbar-left, 8px) !important;
    top: var(--board-mobile-rightbar-top, 62px) !important;
    right: auto !important;
    bottom: auto !important;
    z-index: 2147482450 !important;
    display: grid !important;
    grid-template-columns: 132px minmax(0, 1fr) !important;
    align-items: stretch !important;
    gap: 10px !important;
    width: var(--board-mobile-rightbar-width, calc(100vw - 16px)) !important;
    height: var(--board-mobile-rightbar-height, 220px) !important;
    padding: 10px !important;
    border: 1px solid rgba(148, 184, 163, 0.22) !important;
    border-radius: 22px !important;
    background: rgba(0, 0, 0, 0.76) !important;
    box-shadow: 0 18px 48px rgba(0, 0, 0, 0.42);
    transform: translateY(-18px) scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    overflow: auto !important;
    overscroll-behavior: contain !important;
    touch-action: pan-x pan-y !important;
    transition: none !important;
    will-change: left, top, transform;
  }




  .board-app.is-mobile-right-menu-open .board-rightbar-layer {
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }




  .board-side-toggle {
    display: none !important;
  }




  .right-clock-slot {
    position: static !important;
    display: block !important;
    align-self: stretch !important;
    width: 132px !important;
    max-width: 132px !important;
    height: 132px !important;
    max-height: 132px !important;
    min-height: 0 !important;
    margin: 0 !important;
    padding: 0 !important;
    aspect-ratio: 1 / 1;
    border: 1px solid rgba(148, 184, 163, 0.18);
    border-radius: 18px;
    overflow: hidden;
    background: rgba(0, 18, 10, 0.82);
  }




  .right-clock-slot__frame {
    display: block !important;
    width: 100% !important;
    height: 100% !important;
    border: 0;
    transform: translateZ(0);
  }




  .right-status-panel {
    position: static !important;
    display: grid !important;
    grid-template-rows: auto minmax(0, 1fr) !important;
    align-self: stretch !important;
    width: 100% !important;
    max-width: none !important;
    min-width: 0 !important;
    min-height: 0 !important;
    padding: 0 !important;
    border: 0 !important;
    border-radius: 0 !important;
    background: transparent !important;
    box-shadow: none !important;
    transform: none !important;
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    overflow: hidden !important;
    touch-action: pan-x pan-y !important;
  }




  .right-status-panel:not(.is-open) {
    grid-template-columns: 52px;
    width: 52px !important;
    max-width: 52px !important;
    overflow: visible !important;
  }




  .right-status-panel:not(.is-open) .right-status-panel__body,
  .right-status-panel:not(.is-open) .right-status-panel__header h2,
  .right-status-panel:not(.is-open) .right-status-panel__header .status-pill,
  .right-status-panel:not(.is-open) .board-status {
    display: none !important;
  }




  .right-status-panel__header {
    min-height: 42px !important;
  }




  .right-status-panel__close {
    min-width: 42px !important;
    min-height: 42px !important;
  }




  .right-status-panel__body {
    display: flex !important;
    flex-direction: row !important;
    gap: 10px !important;
    min-height: 0 !important;
    overflow-x: auto !important;
    overflow-y: auto !important;
    padding: 0 2px 4px 0 !important;
    overscroll-behavior: contain;
    touch-action: pan-x pan-y !important;
    -webkit-overflow-scrolling: touch;
  }




  .right-status-panel__body > * {
    flex: 0 0 min(240px, 44vw) !important;
    min-width: 180px !important;
  }




  /* 横向きスマホの拡大縮小スライダーは左下に固定し、ツールモード時だけ表示します。 */
  .board-rightbar-layer > .board-zoom-panel {
    display: none !important;
  }




  .board-mobile-zoom-panel {
    position: fixed !important;
    left: var(--board-mobile-zoom-left, 8px) !important;
    top: var(--board-mobile-zoom-top, calc(100vh - 86px)) !important;
    right: auto !important;
    bottom: auto !important;
    z-index: 2147482800 !important;
    display: none !important;
    grid-template-columns: auto minmax(120px, 1fr) !important;
    align-items: center !important;
    gap: 8px !important;
    width: var(--board-mobile-zoom-width, 260px) !important;
    height: 42px !important;
    min-height: 42px !important;
    max-height: 42px !important;
    padding: 6px 10px !important;
    border: 1px solid rgba(148, 184, 163, 0.18) !important;
    border-radius: 999px !important;
    background: rgba(0, 0, 0, 0.42) !important;
    box-shadow: 0 8px 22px rgba(0, 0, 0, 0.22) !important;
    color: rgba(255, 255, 255, 0.96) !important;
    pointer-events: auto !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    transition: none !important;
    will-change: left, top, transform;
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
  }




  body.is-board-mobile-tool-mode .board-mobile-zoom-panel {
    display: grid !important;
  }




  .board-mobile-zoom-panel__percent {
    display: grid !important;
    place-items: center !important;
    min-width: 76px !important;
    width: 76px !important;
    height: 30px !important;
    min-height: 30px !important;
    padding: 0 10px !important;
    border: 1px solid rgba(148, 184, 163, 0.20) !important;
    border-radius: 999px !important;
    background: rgba(0, 0, 0, 0.36) !important;
    color: rgba(255, 255, 255, 0.96) !important;
    font-size: 0.9rem !important;
    font-weight: 800 !important;
    line-height: 1 !important;
    text-align: center !important;
    touch-action: manipulation !important;
    cursor: pointer !important;
    -webkit-tap-highlight-color: transparent !important;
  }




  .board-mobile-zoom-panel__slider {
    width: 100% !important;
    min-width: 120px !important;
    height: 30px !important;
    min-height: 30px !important;
    margin: 0 !important;
    accent-color: rgba(52, 211, 153, 0.9);
    touch-action: pan-x !important;
  }




  /* 横向きスマホでも黒板の描画範囲だけを示し、PC表示には影響させません。 */
  .board-canvas-zoom-layer::after {
    content: "";
    position: absolute;
    inset: 0;
    z-index: 4;
    box-sizing: border-box;
    border: 3px solid rgba(52, 211, 153, 0.72);
    border-radius: 0;
    box-shadow:
      inset 0 0 0 1px rgba(255, 255, 255, 0.16),
      0 0 14px rgba(52, 211, 153, 0.28);
    pointer-events: none;
  }




  /* 横向きスマホの設定ポップアップは、表示できるだけではなく操作できることを優先します。 */
  .board-app.is-mobile-settings-open .board-topbar-layer,
  .board-app.is-mobile-settings-open .board-topbar-layer * {
    pointer-events: auto !important;
  }





  .board-app.is-mobile-settings-open .board-topbar-layer {
    touch-action: pan-x pan-y !important;
  }





  .board-topbar-content,
  .topbar-category-strip,
  .topbar-category-body,
  .topbar-tool-panel {
    touch-action: pan-x pan-y !important;
    -webkit-overflow-scrolling: touch;
  }





  .topbar-category-body {
    padding: 8px !important;
  }





  .topbar-tool-panel {
    gap: 12px !important;
    min-height: 68px !important;
    align-items: center !important;
  }





  .topbar-category-body .compact-field {
    gap: 8px !important;
    font-size: 0.94rem !important;
  }





  .topbar-category-body .compact-field span {
    font-size: 0.84rem !important;
  }





  .topbar-category-body .compact-field input[type='color'] {
    width: 58px !important;
    min-width: 58px !important;
    height: 52px !important;
  }





  .topbar-category-body .compact-field input[type='range'] {
    width: 190px !important;
    min-width: 190px !important;
    min-height: 52px !important;
    touch-action: pan-x !important;
  }





  .topbar-category-body .compact-field--select select,
  .topbar-category-body .compact-field--number input,
  .topbar-category-body .compact-field--mini input {
    width: 110px !important;
    min-height: 52px !important;
    font-size: 1.04rem !important;
  }





  .topbar-category-body .compact-check-field,
  .topbar-category-body .button--small.selection-metrics-apply {
    min-height: 52px !important;
    padding: 0 16px !important;
    font-size: 1rem !important;
  }





  .preset-chip {
    width: 38px !important;
    height: 38px !important;
  }





  .preset-mini-button {
    width: 48px !important;
    min-width: 48px !important;
    height: 48px !important;
    font-size: 1rem !important;
  }





  /* 右バー内の状態表示は、横リストとして横にも縦にも動かせるようにします。 */
  .right-status-panel__body {
    max-height: none !important;
    touch-action: pan-x pan-y !important;
  }





  .right-status-panel__body > * {
    max-height: none !important;
    overflow: visible !important;
  }





  .status-panel-box {
    min-height: 118px !important;
  }





  /* Phase 3: 横向きスマホで、閉じているHUDが黒板のタップ判定を奪わないようにします。 */
  .board-app:not(.is-mobile-tool-mode) .board-leftbar-layer,
  .board-app:not(.is-mobile-tool-mode) .board-leftbar-layer *,
  .board-app:not(.is-mobile-settings-open) .board-topbar-layer,
  .board-app:not(.is-mobile-settings-open) .board-topbar-layer *,
  .board-app:not(.is-mobile-right-menu-open) .board-rightbar-layer,
  .board-app:not(.is-mobile-right-menu-open) .board-rightbar-layer *,
  body:not(.is-board-mobile-tool-mode) .board-mobile-zoom-panel,
  body:not(.is-board-mobile-tool-mode) .board-mobile-zoom-panel *,
  .board-mobile-subtool-palette[hidden],
  .board-mobile-subtool-palette[hidden] * {
    pointer-events: none !important;
    visibility: hidden !important;
  }




  /* Phase 3: 開いているHUDだけを操作可能に戻します。 */
  .board-app.is-mobile-tool-mode .board-leftbar-layer,
  .board-app.is-mobile-tool-mode .board-leftbar-layer *,
  .board-app.is-mobile-settings-open .board-topbar-layer,
  .board-app.is-mobile-settings-open .board-topbar-layer *,
  .board-app.is-mobile-right-menu-open .board-rightbar-layer,
  .board-app.is-mobile-right-menu-open .board-rightbar-layer *,
  body.is-board-mobile-tool-mode .board-mobile-zoom-panel,
  body.is-board-mobile-tool-mode .board-mobile-zoom-panel * {
    visibility: visible !important;
  }




  /* Phase 3: PC用の子メニューは横向きスマホでは使わず、見えない当たり判定も残さないようにします。 */
  .tool-group-menu,
  .tool-group.is-open .tool-group-menu,
  .tool-group-menu.is-mobile-floating-tool-menu {
    display: none !important;
    visibility: hidden !important;
    opacity: 0 !important;
    pointer-events: none !important;
  }




  /* Phase 4: 横向きスマホの拡大縮小スライダーは、visualViewport計算値で画面左下へ追従させます。 */
  .board-mobile-zoom-panel {
    position: fixed !important;
    left: var(--board-mobile-zoom-left, calc(8px + env(safe-area-inset-left, 0px))) !important;
    top: var(--board-mobile-zoom-top, calc(100vh - 58px - env(safe-area-inset-bottom, 0px))) !important;
    right: auto !important;
    bottom: auto !important;
    width: var(--board-mobile-zoom-width, min(320px, calc(100vw - 16px - env(safe-area-inset-left, 0px) - env(safe-area-inset-right, 0px)))) !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    will-change: left, top, transform;
  }




  /* Phase 3: 横向きスマホで設定ポップアップを開いている間は、スクロールと入力操作を明示的に許可します。 */
  .board-app.is-mobile-settings-open .board-topbar-layer,
  .board-app.is-mobile-settings-open .board-topbar-content,
  .board-app.is-mobile-settings-open .topbar-category-strip,
  .board-app.is-mobile-settings-open .topbar-category-body,
  .board-app.is-mobile-settings-open .topbar-tool-panel {
    pointer-events: auto !important;
    touch-action: pan-x pan-y !important;
    overscroll-behavior: contain !important;
    -webkit-overflow-scrolling: touch;
  }




  /* Phase 3: 横向きスマホの描画キャンバスは、ツールモード時にHUD以外の黒板面で確実に反応させます。 */
  .board-app.is-mobile-tool-mode .board-canvas-scroll,
  .board-app.is-mobile-tool-mode .board-canvas-zoom-layer,
  .board-app.is-mobile-tool-mode .board-canvas-page,
  .board-app.is-mobile-tool-mode #boardInteractionCanvas {
    pointer-events: auto !important;
  }




  /* Phase 5: 横向きスマホ専用の軽量化です。PC表示には影響させません。 */
  /* 半透明の見た目は背景色で残し、重くなりやすい blur 合成だけを止めます。 */
  .board-mobile-hud,
  .board-leftbar-layer,
  .board-topbar-layer,
  .board-rightbar-layer,
  .board-mobile-subtool-palette,
  .board-mobile-zoom-panel {
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
  }




  /* Phase 5: 常時の合成レイヤー予約を減らし、スマホ側のメモリ負荷を抑えます。 */
  /* 位置更新自体はJS側のCSS変数で続けるため、HUD追従は維持します。 */
  .board-mobile-hud,
  .board-leftbar-layer,
  .board-topbar-layer,
  .board-rightbar-layer,
  .board-mobile-subtool-palette,
  .board-mobile-zoom-panel {
    will-change: auto !important;
  }




  /* Phase 5: 横向きスマホでは影を薄くし、描画・ズーム中の再合成負荷を下げます。 */
  .board-leftbar-layer,
  .board-topbar-layer,
  .board-rightbar-layer,
  .board-mobile-subtool-palette,
  .board-mobile-zoom-panel {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.18) !important;
  }




  .board-body[data-user-role="student"] #toggleFixedProblemButton,
  .board-app[data-user-role="student"] #toggleFixedProblemButton {
    display: none !important;
  }
}


/* ===== Blackboard mobile phase 21: separated header / fixed-problem / board areas ===== */
@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  /* ヘッダーはピンチズームの見た目倍率に影響されない固定操作領域として残します。 */
  /* 固定表示領域と黒板は、このヘッダーの下へ別領域として並べます。 */
  .board-app {
    --board-mobile-header-layout-height: calc(var(--board-mobile-header-height, 64px) * var(--board-mobile-vv-inverse-scale, 1));
    --board-mobile-fixed-problem-visual-height: 62px;
    --fixed-problem-height: var(--board-mobile-fixed-problem-visual-height);
    --fixed-problem-offset: var(--fixed-problem-height);
  }



  /* 黒板ワークスペースはヘッダーの下に固定します。 */
  /* この中で、固定表示領域 → 黒板 の順に重ならず配置します。 */
  .board-workspace-layer {
    top: var(--board-mobile-header-layout-height) !important;
    overflow: hidden !important;
  }



  /* 固定表示領域は黒板の手前に重ねるのではなく、ヘッダー下の独立した表示領域として固定します。 */
  /* visualViewport の座標に追従するため、ページ側のスクロールやピンチ後の視点移動では流れていきません。 */
  .fixed-problem-panel {
    position: fixed !important;
    left: var(--board-mobile-vv-left, 0px) !important;
    top: calc(var(--board-mobile-vv-top, 0px) + var(--board-mobile-header-layout-height, 64px)) !important;
    right: auto !important;
    width: var(--board-mobile-vv-width, 100vw) !important;
    height: var(--fixed-problem-height) !important;
    z-index: 2147482100 !important;
    transform: none !important;
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
  }



  /* 固定表示領域が非表示のときは、実質的に高さ0pxの扱いにします。 */
  /* 講師側の表示/非表示連動でこの状態に入ると、黒板はヘッダー直下から始まります。 */
  .fixed-problem-panel.is-collapsed {
    height: 0 !important;
    min-height: 0 !important;
    max-height: 0 !important;
    border-bottom: none !important;
    transform: none !important;
    opacity: 0 !important;
    visibility: hidden !important;
    pointer-events: none !important;
  }



  /* 固定表示領域が表示されているときは、黒板本体を固定表示領域の下から開始します。 */
  /* これで固定表示領域が黒板を隠さず、ヘッダー・固定表示領域・黒板が縦に分かれます。 */
  .board-canvas-shell {
    top: var(--fixed-problem-offset) !important;
    bottom: 0 !important;
  }



  /* 固定表示領域が非表示のときは、固定表示領域の高さを0pxとして黒板を上へ詰めます。 */
  /* HTML上で隣接していない場合も拾えるよう、汎用兄弟セレクタで指定します。 */
  .fixed-problem-panel.is-collapsed ~ .board-canvas-shell {
    top: 0 !important;
  }



  /* 固定表示領域内の画像や空表示は、固定表示領域の高さ内に収めます。 */
  .fixed-problem-panel__body,
  .fixed-problem-image,
  .fixed-problem-empty {
    height: 100% !important;
    max-height: 100% !important;
  }
}



/* ===== Blackboard mobile landscape phase 10: separated header / fixed-problem / board areas ===== */
@media (pointer: coarse) and (orientation: landscape) and (max-height: 520px) {
  /* 横向きスマホでも、ヘッダー・固定表示領域・黒板を重ねずに縦方向へ分離します。 */
  .board-app {
    --board-mobile-header-layout-height: calc(var(--board-mobile-header-height, 64px) * var(--board-mobile-vv-inverse-scale, 1));
    --board-mobile-fixed-problem-visual-height: 62px;
    --fixed-problem-height: var(--board-mobile-fixed-problem-visual-height);
    --fixed-problem-offset: var(--fixed-problem-height);
  }



  .board-workspace-layer {
    top: var(--board-mobile-header-layout-height) !important;
    overflow: hidden !important;
  }



  .fixed-problem-panel {
    position: fixed !important;
    left: var(--board-mobile-vv-left, 0px) !important;
    top: calc(var(--board-mobile-vv-top, 0px) + var(--board-mobile-header-layout-height, 64px)) !important;
    right: auto !important;
    width: var(--board-mobile-vv-width, 100vw) !important;
    height: var(--fixed-problem-height) !important;
    z-index: 2147482100 !important;
    transform: none !important;
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
  }



  .fixed-problem-panel.is-collapsed {
    height: 0 !important;
    min-height: 0 !important;
    max-height: 0 !important;
    border-bottom: none !important;
    transform: none !important;
    opacity: 0 !important;
    visibility: hidden !important;
    pointer-events: none !important;
  }



  .board-canvas-shell {
    top: var(--fixed-problem-offset) !important;
    bottom: 0 !important;
  }



  .fixed-problem-panel.is-collapsed ~ .board-canvas-shell {
    top: 0 !important;
  }



  .fixed-problem-panel__body,
  .fixed-problem-image,
  .fixed-problem-empty {
    height: 100% !important;
    max-height: 100% !important;
  }
}



/* ===== Blackboard mobile phase 22: opaque fixed header band / fixed-problem in separate non-scroll area ===== */
@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  /* ヘッダー黒帯は操作ボタンの疑似要素ではなく、黒板アプリ直下の独立レイヤーにします。 */
  /* ボタン側の変形や横幅の変化に引きずられず、常に画面上部を不透明な黒帯で覆います。 */
  .board-app::before {
    content: "";
    position: fixed;
    left: var(--board-mobile-vv-left, 0px);
    top: var(--board-mobile-vv-top, 0px);
    width: var(--board-mobile-vv-width, 100vw);
    height: var(--board-mobile-header-layout-height, var(--board-mobile-header-height, 64px));
    z-index: 2147482550;
    display: block;
    background: rgba(0, 0, 0, 1);
    border-bottom: 1px solid rgba(148, 184, 163, 0.24);
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.28);
    pointer-events: none;
  }



  /* Phase 18で作った操作ボタン側の黒帯は、親要素の変形に影響されやすいため無効化します。 */
  /* 黒帯は .board-app::before に一本化し、ボタンはその上に載せるだけにします。 */
  .board-mobile-controls::before {
    display: none !important;
    content: none !important;
  }



  /* 操作ボタンは黒帯より前面に固定します。 */
  /* ボタン自体はこれまで通り、ピンチズームに対して大きさが変わりにくいHUDとして扱います。 */
  .board-mobile-controls {
    z-index: 2147482600 !important;
  }



  /* 固定表示領域は fixed ではなく、ワークスペース内の独立領域として配置します。 */
  /* これにより、黒板スクロールには流されず、かつブラウザのピンチズームでは中身ごと自然に拡大縮小します。 */
  .fixed-problem-panel {
    position: absolute !important;
    left: 0 !important;
    right: 0 !important;
    top: 0 !important;
    width: auto !important;
    height: var(--fixed-problem-height) !important;
    z-index: 20 !important;
    transform: none !important;
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
    background: rgba(0, 40, 24, 1) !important;
  }



  /* 固定表示領域の中身は、領域の幅と高さに完全追従させます。 */
  /* 画像だけ拡大しない状態を避けるため、body と画像を領域いっぱいに伸ばします。 */
  .fixed-problem-panel__body {
    position: absolute !important;
    inset: 0 !important;
    width: 100% !important;
    height: 100% !important;
    min-height: 0 !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    overflow: hidden !important;
  }



  .fixed-problem-image,
  .fixed-problem-empty {
    width: 100% !important;
    height: 100% !important;
    max-width: 100% !important;
    max-height: 100% !important;
  }



  .fixed-problem-image {
    object-fit: contain !important;
  }



  /* 固定表示領域が非表示のときは、本当に高さ0の領域として扱います。 */
  /* 黒板はヘッダー直下まで詰め、表示時だけ固定表示領域の下へ逃がします。 */
  .fixed-problem-panel.is-collapsed {
    height: 0 !important;
    min-height: 0 !important;
    max-height: 0 !important;
    border-bottom: none !important;
    transform: none !important;
    opacity: 0 !important;
    visibility: hidden !important;
    pointer-events: none !important;
  }



  .fixed-problem-panel.is-collapsed .fixed-problem-panel__body,
  .fixed-problem-panel.is-collapsed .fixed-problem-panel__actions {
    display: none !important;
  }



  /* 黒板本体は固定表示領域の下に置き、固定表示領域と重ならないようにします。 */
  .board-canvas-shell {
    top: var(--fixed-problem-offset) !important;
    bottom: 0 !important;
  }



  /* 固定表示領域が閉じているときは、黒板をヘッダー直下へ詰めます。 */
  .fixed-problem-panel.is-collapsed ~ .board-canvas-shell {
    top: 0 !important;
  }
}



/* ===== Blackboard mobile landscape phase 11: opaque fixed header band / fixed-problem in separate non-scroll area ===== */
@media (pointer: coarse) and (orientation: landscape) and (max-height: 520px) {
  /* 横向きスマホでも、ヘッダー黒帯は不透明な独立レイヤーとして固定します。 */
  .board-app::before {
    content: "";
    position: fixed;
    left: var(--board-mobile-vv-left, 0px);
    top: var(--board-mobile-vv-top, 0px);
    width: var(--board-mobile-vv-width, 100vw);
    height: var(--board-mobile-header-layout-height, var(--board-mobile-header-height, 64px));
    z-index: 2147482550;
    display: block;
    background: rgba(0, 0, 0, 1);
    border-bottom: 1px solid rgba(148, 184, 163, 0.24);
    pointer-events: none;
  }



  .board-mobile-controls::before {
    display: none !important;
    content: none !important;
  }



  .board-mobile-controls {
    z-index: 2147482600 !important;
  }



  /* 横向きスマホでも、固定表示領域は黒板と重ねず、ワークスペース内の独立領域として扱います。 */
  .fixed-problem-panel {
    position: absolute !important;
    left: 0 !important;
    right: 0 !important;
    top: 0 !important;
    width: auto !important;
    height: var(--fixed-problem-height) !important;
    z-index: 20 !important;
    transform: none !important;
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
    background: rgba(0, 40, 24, 1) !important;
  }



  .fixed-problem-panel__body {
    position: absolute !important;
    inset: 0 !important;
    width: 100% !important;
    height: 100% !important;
    min-height: 0 !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    overflow: hidden !important;
  }



  .fixed-problem-image,
  .fixed-problem-empty {
    width: 100% !important;
    height: 100% !important;
    max-width: 100% !important;
    max-height: 100% !important;
  }



  .fixed-problem-image {
    object-fit: contain !important;
  }



  .fixed-problem-panel.is-collapsed {
    height: 0 !important;
    min-height: 0 !important;
    max-height: 0 !important;
    border-bottom: none !important;
    transform: none !important;
    opacity: 0 !important;
    visibility: hidden !important;
    pointer-events: none !important;
  }



  .fixed-problem-panel.is-collapsed .fixed-problem-panel__body,
  .fixed-problem-panel.is-collapsed .fixed-problem-panel__actions {
    display: none !important;
  }



  .board-canvas-shell {
    top: var(--fixed-problem-offset) !important;
    bottom: 0 !important;
  }



  .fixed-problem-panel.is-collapsed ~ .board-canvas-shell {
    top: 0 !important;
  }
}


/* ===== Blackboard mobile phase 23: fixed HUD / viewport-pinned fixed problem / board below ===== */
@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  /* ヘッダーは黒板や固定表示領域とは別の最前面HUDとして扱います。 */
  /* ピンチズームでも見た目のサイズと位置が変わらないよう、visualViewportの逆スケールを維持します。 */
  .board-app {
    --board-mobile-header-height: 64px;
    --board-mobile-header-layout-height: calc(var(--board-mobile-header-height, 64px) * var(--board-mobile-vv-inverse-scale, 1));
    --board-mobile-fixed-problem-visual-height: 62px;
    --fixed-problem-height: var(--board-mobile-fixed-problem-visual-height);
    --fixed-problem-offset: var(--fixed-problem-height);
  }



  /* 不透明なヘッダー黒帯です。 */
  /* ボタンとは別レイヤーにし、スクロールした黒板が後ろに透けないようにします。 */
  .board-app::before {
    content: "" !important;
    position: fixed !important;
    left: var(--board-mobile-vv-left, 0px) !important;
    top: var(--board-mobile-vv-top, 0px) !important;
    width: var(--board-mobile-vv-width, 100vw) !important;
    height: var(--board-mobile-header-layout-height, 64px) !important;
    z-index: 2147483500 !important;
    display: block !important;
    background: rgba(0, 0, 0, 1) !important;
    border-bottom: 1px solid rgba(148, 184, 163, 0.24) !important;
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.28) !important;
    pointer-events: none !important;
  }



  /* ヘッダー上の各ボタンです。 */
  /* 黒帯よりさらに前面へ置き、ズーム時も隠れないようにします。 */
  .board-mobile-controls {
    position: fixed !important;
    left: calc(var(--board-mobile-vv-left, 0px) + 8px) !important;
    top: calc(var(--board-mobile-vv-top, 0px) + 8px) !important;
    right: auto !important;
    width: calc(var(--board-mobile-vv-width, 100vw) - 16px) !important;
    height: var(--board-mobile-control-button-size, 48px) !important;
    min-height: var(--board-mobile-control-button-size, 48px) !important;
    z-index: 2147483600 !important;
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    gap: 6px !important;
    padding: 0 !important;
    background: transparent !important;
    border: 0 !important;
    box-shadow: none !important;
    pointer-events: none !important;
    touch-action: auto !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    will-change: left, top, transform !important;
  }



  /* 旧ヘッダー黒帯は二重表示を防ぐため無効化します。 */
  /* 黒帯は .board-app::before に一本化します。 */
  .board-mobile-controls::before {
    display: none !important;
    content: none !important;
  }



  /* ボタン本体のタップは有効にします。 */
  /* 親だけ pointer-events none にしているため、子だけ操作可能に戻します。 */
  .board-mobile-control-main,
  .board-mobile-menu-toggle,
  .board-mobile-history-button,
  .board-mobile-mode-toggle {
    position: relative !important;
    z-index: 1 !important;
    pointer-events: auto !important;
  }



  /* ワークスペースはヘッダーの下から始めます。 */
  /* ヘッダーは逆スケール補正済みなので、ピンチズーム時も見た目64px相当に留まります。 */
  .board-workspace-layer {
    top: var(--board-mobile-header-layout-height, 64px) !important;
    left: 0 !important;
    right: 0 !important;
    overflow: hidden !important;
  }



  /* 固定表示領域です。 */
  /* 縦方向はヘッダー直下に固定、横方向とズームはvisualViewportへ追従させます。 */
  .fixed-problem-panel {
    position: fixed !important;
    left: var(--board-mobile-vv-left, 0px) !important;
    top: calc(var(--board-mobile-vv-top, 0px) + var(--board-mobile-header-layout-height, 64px)) !important;
    right: auto !important;
    width: var(--board-mobile-vv-width, 100vw) !important;
    height: var(--fixed-problem-height, 62px) !important;
    z-index: 2147482400 !important;
    display: block !important;
    transform: none !important;
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
    background: rgba(0, 40, 24, 1) !important;
    border-bottom: 1px solid rgba(148, 184, 163, 0.24) !important;
    overflow: hidden !important;
  }



  /* 固定表示領域の中身です。 */
  /* 外枠だけでなく画像や空表示も、領域サイズへ完全追従させます。 */
  .fixed-problem-panel__body {
    position: absolute !important;
    inset: 0 !important;
    width: 100% !important;
    height: 100% !important;
    min-height: 0 !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    overflow: hidden !important;
  }



  .fixed-problem-image,
  .fixed-problem-empty {
    display: block !important;
    width: 100% !important;
    height: 100% !important;
    max-width: 100% !important;
    max-height: 100% !important;
  }



  .fixed-problem-image {
    object-fit: contain !important;
  }



  /* 固定表示領域が非表示の状態です。 */
  /* 見た目も当たり判定も0px相当へ落とします。 */
  .fixed-problem-panel.is-collapsed {
    height: 0 !important;
    min-height: 0 !important;
    max-height: 0 !important;
    border-bottom: none !important;
    transform: none !important;
    opacity: 0 !important;
    visibility: hidden !important;
    pointer-events: none !important;
  }



  .fixed-problem-panel.is-collapsed .fixed-problem-panel__body,
  .fixed-problem-panel.is-collapsed .fixed-problem-panel__actions {
    display: none !important;
  }



  /* 黒板は固定表示領域の下に配置します。 */
  /* 固定表示領域を黒板の手前に重ねず、別領域として避けます。 */
  .board-canvas-shell {
    top: var(--fixed-problem-offset, 62px) !important;
    bottom: 0 !important;
  }



  /* 固定表示領域が閉じているときは、黒板をヘッダー直下へ詰めます。 */
  /* 兄弟セレクタと :has の両方で、DOM差分に少し強くしています。 */
  .fixed-problem-panel.is-collapsed ~ .board-canvas-shell,
  .board-workspace-layer:has(.fixed-problem-panel.is-collapsed) .board-canvas-shell {
    top: 0 !important;
  }
}



/* ===== Blackboard mobile landscape phase 12: fixed HUD / viewport-pinned fixed problem / board below ===== */
@media (pointer: coarse) and (orientation: landscape) and (max-height: 520px) {
  /* 横向きスマホでも、縦向きと同じ構成に揃えます。 */
  /* ヘッダーは固定、固定表示領域はヘッダー下固定、黒板は固定表示領域の下です。 */
  .board-app {
    --board-mobile-header-height: 64px;
    --board-mobile-header-layout-height: calc(var(--board-mobile-header-height, 64px) * var(--board-mobile-vv-inverse-scale, 1));
    --board-mobile-fixed-problem-visual-height: 62px;
    --fixed-problem-height: var(--board-mobile-fixed-problem-visual-height);
    --fixed-problem-offset: var(--fixed-problem-height);
  }



  .board-app::before {
    content: "" !important;
    position: fixed !important;
    left: var(--board-mobile-vv-left, 0px) !important;
    top: var(--board-mobile-vv-top, 0px) !important;
    width: var(--board-mobile-vv-width, 100vw) !important;
    height: var(--board-mobile-header-layout-height, 64px) !important;
    z-index: 2147483500 !important;
    display: block !important;
    background: rgba(0, 0, 0, 1) !important;
    border-bottom: 1px solid rgba(148, 184, 163, 0.24) !important;
    pointer-events: none !important;
  }



  .board-mobile-controls {
    position: fixed !important;
    left: calc(var(--board-mobile-vv-left, 0px) + 8px) !important;
    top: calc(var(--board-mobile-vv-top, 0px) + 8px) !important;
    right: auto !important;
    width: calc(var(--board-mobile-vv-width, 100vw) - 16px) !important;
    z-index: 2147483600 !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
  }



  .board-workspace-layer {
    top: var(--board-mobile-header-layout-height, 64px) !important;
    left: 0 !important;
    right: 0 !important;
    overflow: hidden !important;
  }



  .fixed-problem-panel {
    position: fixed !important;
    left: var(--board-mobile-vv-left, 0px) !important;
    top: calc(var(--board-mobile-vv-top, 0px) + var(--board-mobile-header-layout-height, 64px)) !important;
    right: auto !important;
    width: var(--board-mobile-vv-width, 100vw) !important;
    height: var(--fixed-problem-height, 62px) !important;
    z-index: 2147482400 !important;
    display: block !important;
    transform: none !important;
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
    background: rgba(0, 40, 24, 1) !important;
    border-bottom: 1px solid rgba(148, 184, 163, 0.24) !important;
    overflow: hidden !important;
  }



  .fixed-problem-panel__body {
    position: absolute !important;
    inset: 0 !important;
    width: 100% !important;
    height: 100% !important;
    min-height: 0 !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    overflow: hidden !important;
  }



  .fixed-problem-image,
  .fixed-problem-empty {
    display: block !important;
    width: 100% !important;
    height: 100% !important;
    max-width: 100% !important;
    max-height: 100% !important;
  }



  .fixed-problem-image {
    object-fit: contain !important;
  }



  .fixed-problem-panel.is-collapsed {
    height: 0 !important;
    min-height: 0 !important;
    max-height: 0 !important;
    border-bottom: none !important;
    transform: none !important;
    opacity: 0 !important;
    visibility: hidden !important;
    pointer-events: none !important;
  }



  .fixed-problem-panel.is-collapsed .fixed-problem-panel__body,
  .fixed-problem-panel.is-collapsed .fixed-problem-panel__actions {
    display: none !important;
  }



  .board-canvas-shell {
    top: var(--fixed-problem-offset, 62px) !important;
    bottom: 0 !important;
  }



  .fixed-problem-panel.is-collapsed ~ .board-canvas-shell,
  .board-workspace-layer:has(.fixed-problem-panel.is-collapsed) .board-canvas-shell {
    top: 0 !important;
  }
}

/* ===== Blackboard mobile phase 24: lock HUD to visual viewport / scalable fixed-problem content ===== */
@media (max-width: 767px), ((hover: none) and (pointer: coarse) and (max-width: 1100px) and (max-height: 1100px)) {
  .board-app {
    --board-mobile-header-height: 64px;
    --board-mobile-header-gap: 8px;
    --board-mobile-header-gap-layout: calc(var(--board-mobile-header-gap, 8px) * var(--board-mobile-vv-inverse-scale, 1));
    --board-mobile-header-layout-height: calc(var(--board-mobile-header-height, 64px) * var(--board-mobile-vv-inverse-scale, 1));
    --board-mobile-fixed-problem-visual-height: 62px;
    --fixed-problem-height: var(--board-mobile-fixed-problem-visual-height);
    --fixed-problem-offset: var(--fixed-problem-height);
  }

  .board-app::before {
    content: "" !important;
    position: fixed !important;
    left: var(--board-mobile-vv-left, 0px) !important;
    top: var(--board-mobile-vv-top, 0px) !important;
    width: 100vw !important;
    height: var(--board-mobile-header-layout-height, 64px) !important;
    z-index: 2147483500 !important;
    display: block !important;
    background: rgba(0, 0, 0, 1) !important;
    border-bottom: 1px solid rgba(148, 184, 163, 0.24) !important;
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.28) !important;
    pointer-events: none !important;
  }

  .board-mobile-controls {
    position: fixed !important;
    left: calc(var(--board-mobile-vv-left, 0px) + var(--board-mobile-header-gap-layout, 8px)) !important;
    top: calc(var(--board-mobile-vv-top, 0px) + var(--board-mobile-header-gap-layout, 8px)) !important;
    right: auto !important;
    width: calc(100vw - (16px * var(--board-mobile-vv-inverse-scale, 1))) !important;
    min-width: calc(100vw - (16px * var(--board-mobile-vv-inverse-scale, 1))) !important;
    max-width: calc(100vw - (16px * var(--board-mobile-vv-inverse-scale, 1))) !important;
    height: 48px !important;
    min-height: 48px !important;
    max-height: 48px !important;
    z-index: 2147483600 !important;
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    gap: 6px !important;
    padding: 0 !important;
    margin: 0 !important;
    background: transparent !important;
    border: 0 !important;
    box-shadow: none !important;
    pointer-events: none !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
    will-change: left, top, transform !important;
  }

  .board-mobile-controls::before {
    display: none !important;
    content: none !important;
  }

  .board-mobile-control-main {
    position: relative !important;
    z-index: 1 !important;
    display: inline-flex !important;
    align-items: center !important;
    gap: 6px !important;
    max-width: calc(100vw - 72px) !important;
    pointer-events: auto !important;
    transform: none !important;
  }

  .board-mobile-mode-toggle {
    flex: 0 0 112px !important;
    width: 112px !important;
    min-width: 112px !important;
    max-width: 112px !important;
    height: 48px !important;
    min-height: 48px !important;
    max-height: 48px !important;
    padding: 0 11px !important;
    gap: 6px !important;
  }

  .board-mobile-mode-toggle__lamp {
    flex: 0 0 15px !important;
    width: 15px !important;
    height: 15px !important;
  }

  .board-mobile-mode-toggle__text {
    font-size: 0.92rem !important;
    line-height: 1 !important;
    white-space: nowrap !important;
  }

  .board-mobile-history-button,
  .board-mobile-menu-toggle {
    flex: 0 0 48px !important;
    width: 48px !important;
    min-width: 48px !important;
    max-width: 48px !important;
    height: 48px !important;
    min-height: 48px !important;
    max-height: 48px !important;
    padding: 0 !important;
    font-size: 1.32rem !important;
  }

  .board-mobile-mode-toggle,
  .board-mobile-history-button,
  .board-mobile-menu-toggle {
    position: relative !important;
    z-index: 1 !important;
    pointer-events: auto !important;
    touch-action: manipulation !important;
    transform: none !important;
  }

  .board-workspace-layer {
    top: var(--board-mobile-header-layout-height, 64px) !important;
    left: 0 !important;
    right: 0 !important;
    overflow: hidden !important;
  }

  .fixed-problem-panel {
    position: fixed !important;
    left: var(--board-mobile-vv-left, 0px) !important;
    top: calc(var(--board-mobile-vv-top, 0px) + var(--board-mobile-header-layout-height, 64px)) !important;
    right: auto !important;
    width: var(--board-mobile-vv-width, 100vw) !important;
    height: var(--fixed-problem-height, 62px) !important;
    z-index: 2147482400 !important;
    display: block !important;
    transform: none !important;
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
    background: rgba(0, 40, 24, 1) !important;
    border-bottom: 1px solid rgba(148, 184, 163, 0.24) !important;
    overflow: hidden !important;
  }

  .fixed-problem-panel__body {
    position: absolute !important;
    left: 0 !important;
    top: 0 !important;
    width: 100vw !important;
    min-width: 100vw !important;
    height: 100% !important;
    min-height: 0 !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    overflow: hidden !important;
    transform: translateX(calc(-1 * var(--board-mobile-vv-left, 0px))) !important;
    transform-origin: left top !important;
  }

  .fixed-problem-image,
  .fixed-problem-empty {
    display: block !important;
    width: 100% !important;
    height: 100% !important;
    max-width: none !important;
    max-height: none !important;
  }

  .fixed-problem-image {
    object-fit: contain !important;
  }

  .fixed-problem-panel.is-collapsed {
    height: 0 !important;
    min-height: 0 !important;
    max-height: 0 !important;
    border-bottom: none !important;
    transform: none !important;
    opacity: 0 !important;
    visibility: hidden !important;
    pointer-events: none !important;
  }

  .fixed-problem-panel.is-collapsed .fixed-problem-panel__body,
  .fixed-problem-panel.is-collapsed .fixed-problem-panel__actions {
    display: none !important;
  }

  .board-canvas-shell {
    top: var(--fixed-problem-offset, 62px) !important;
    bottom: 0 !important;
  }

  .fixed-problem-panel.is-collapsed ~ .board-canvas-shell,
  .board-workspace-layer:has(.fixed-problem-panel.is-collapsed) .board-canvas-shell {
    top: 0 !important;
  }
}

/* ===== Blackboard mobile landscape phase 13: lock HUD to visual viewport / scalable fixed-problem content ===== */
@media (pointer: coarse) and (orientation: landscape) and (max-height: 520px) {
  .board-app {
    --board-mobile-header-height: 64px;
    --board-mobile-header-gap: 8px;
    --board-mobile-header-gap-layout: calc(var(--board-mobile-header-gap, 8px) * var(--board-mobile-vv-inverse-scale, 1));
    --board-mobile-header-layout-height: calc(var(--board-mobile-header-height, 64px) * var(--board-mobile-vv-inverse-scale, 1));
    --board-mobile-fixed-problem-visual-height: 62px;
    --fixed-problem-height: var(--board-mobile-fixed-problem-visual-height);
    --fixed-problem-offset: var(--fixed-problem-height);
  }

  .board-app::before {
    content: "" !important;
    position: fixed !important;
    left: var(--board-mobile-vv-left, 0px) !important;
    top: var(--board-mobile-vv-top, 0px) !important;
    width: 100vw !important;
    height: var(--board-mobile-header-layout-height, 64px) !important;
    z-index: 2147483500 !important;
    display: block !important;
    background: rgba(0, 0, 0, 1) !important;
    border-bottom: 1px solid rgba(148, 184, 163, 0.24) !important;
    pointer-events: none !important;
  }

  .board-mobile-controls {
    position: fixed !important;
    left: calc(var(--board-mobile-vv-left, 0px) + var(--board-mobile-header-gap-layout, 8px)) !important;
    top: calc(var(--board-mobile-vv-top, 0px) + var(--board-mobile-header-gap-layout, 8px)) !important;
    right: auto !important;
    width: calc(100vw - (16px * var(--board-mobile-vv-inverse-scale, 1))) !important;
    min-width: calc(100vw - (16px * var(--board-mobile-vv-inverse-scale, 1))) !important;
    max-width: calc(100vw - (16px * var(--board-mobile-vv-inverse-scale, 1))) !important;
    height: 48px !important;
    min-height: 48px !important;
    max-height: 48px !important;
    z-index: 2147483600 !important;
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    gap: 6px !important;
    padding: 0 !important;
    background: transparent !important;
    border: 0 !important;
    box-shadow: none !important;
    pointer-events: none !important;
    transform: scale(var(--board-mobile-vv-inverse-scale, 1)) !important;
    transform-origin: left top !important;
  }

  .board-mobile-control-main {
    position: relative !important;
    z-index: 1 !important;
    display: inline-flex !important;
    align-items: center !important;
    gap: 6px !important;
    max-width: calc(100vw - 72px) !important;
    pointer-events: auto !important;
    transform: none !important;
  }

  .board-mobile-mode-toggle {
    flex: 0 0 112px !important;
    width: 112px !important;
    min-width: 112px !important;
    max-width: 112px !important;
    height: 48px !important;
    min-height: 48px !important;
    max-height: 48px !important;
  }

  .board-mobile-history-button,
  .board-mobile-menu-toggle {
    flex: 0 0 48px !important;
    width: 48px !important;
    min-width: 48px !important;
    max-width: 48px !important;
    height: 48px !important;
    min-height: 48px !important;
    max-height: 48px !important;
  }

  .board-workspace-layer {
    top: var(--board-mobile-header-layout-height, 64px) !important;
    left: 0 !important;
    right: 0 !important;
    overflow: hidden !important;
  }

  .fixed-problem-panel {
    position: fixed !important;
    left: var(--board-mobile-vv-left, 0px) !important;
    top: calc(var(--board-mobile-vv-top, 0px) + var(--board-mobile-header-layout-height, 64px)) !important;
    right: auto !important;
    width: var(--board-mobile-vv-width, 100vw) !important;
    height: var(--fixed-problem-height, 62px) !important;
    z-index: 2147482400 !important;
    display: block !important;
    transform: none !important;
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
    background: rgba(0, 40, 24, 1) !important;
    border-bottom: 1px solid rgba(148, 184, 163, 0.24) !important;
    overflow: hidden !important;
  }

  .fixed-problem-panel__body {
    position: absolute !important;
    left: 0 !important;
    top: 0 !important;
    width: 100vw !important;
    min-width: 100vw !important;
    height: 100% !important;
    min-height: 0 !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    overflow: hidden !important;
    transform: translateX(calc(-1 * var(--board-mobile-vv-left, 0px))) !important;
    transform-origin: left top !important;
  }

  .fixed-problem-image,
  .fixed-problem-empty {
    display: block !important;
    width: 100% !important;
    height: 100% !important;
    max-width: none !important;
    max-height: none !important;
  }

  .fixed-problem-image {
    object-fit: contain !important;
  }

  .fixed-problem-panel.is-collapsed {
    height: 0 !important;
    min-height: 0 !important;
    max-height: 0 !important;
    border-bottom: none !important;
    transform: none !important;
    opacity: 0 !important;
    visibility: hidden !important;
    pointer-events: none !important;
  }

  .fixed-problem-panel.is-collapsed .fixed-problem-panel__body,
  .fixed-problem-panel.is-collapsed .fixed-problem-panel__actions {
    display: none !important;
  }

  .board-canvas-shell {
    top: var(--fixed-problem-offset, 62px) !important;
    bottom: 0 !important;
  }

  .fixed-problem-panel.is-collapsed ~ .board-canvas-shell,
  .board-workspace-layer:has(.fixed-problem-panel.is-collapsed) .board-canvas-shell {
    top: 0 !important;
  }
}


/* Online-Class81 number line and mixed text patch */
.number-line-settings {
  display: grid;
  grid-template-columns: repeat(5, minmax(82px, 1fr));
  gap: 6px;
  align-items: end;
  width: min(100%, 760px);
}

.number-line-settings[hidden] {
  display: none !important;
}

@media (max-width: 760px) {
  .number-line-settings {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* 画像レイヤー切替UI。画像を通常オブジェクトとして扱うか、奥レイヤーの背景画像として扱うかを切り替えます。 */
.image-layer-toggle-field {
    gap: 6px;
    padding-inline: 8px;
}

/* 背景救済UI。背景化して選択できなくなった画像を、見えている範囲から通常オブジェクトへ戻します。 */
.image-layer-restore-field select {
    min-width: 180px;
}

.image-layer-toggle-field:has(input:checked) {
    border-color: rgba(96, 165, 250, 0.75);
    background: rgba(37, 99, 235, 0.18);
}

/* PDF貼付と画像背景化の補助UIです。
   通常画像の保存・描画には関わらず、上バー内の操作項目だけを整えます。 */
.image-pdf-background-field {
  gap: 4px;
  white-space: nowrap;
}

#choosePdfButton {
  min-width: 76px;
}

/* PDF関連の操作を専用タブへ分けたため、情報表示は1行固定・省略表示にします。
   ファイル名が長いPDFでも上バー下段の高さを増やさず、横にも伸びすぎないようにします。 */
.current-image-box--pdf {
  flex-basis: 220px;
  width: 220px;
  min-width: 0;
  max-width: 220px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.topbar-tool-panel--image-pdf,
.topbar-tool-panel--image-layer {
  gap: 4px;
}

.topbar-tool-panel--image-pdf .button--small,
.topbar-tool-panel--image-layer .button--small,
.topbar-tool-panel--image-processing .button--small {
  white-space: nowrap;
}

.image-pdf-range-field input {
  width: 64px;
}

.image-pdf-range-field--end span {
  min-width: 12px;
  text-align: center;
}

#armPdfPasteButton.is-active {
  border-color: rgba(96, 165, 250, 0.75);
  background: rgba(37, 99, 235, 0.18);
}


/* 黒板側で生徒・保護者本人の追従状態を確認するための小さな表示です。 */
/* 追従の実行やページ移動はまだ行わず、状態表示だけを独立して扱います。 */
.board-follow-state-indicator {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 8800;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  max-width: min(320px, calc(100vw - 36px));
  padding: 8px 12px;
  border: 1px solid rgba(148, 163, 184, 0.42);
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.82);
  color: #e5e7eb;
  font-size: 13px;
  font-weight: 700;
  line-height: 1.3;
  box-shadow: 0 10px 24px rgba(15, 23, 42, 0.24);
  pointer-events: none;
  backdrop-filter: blur(10px);
}

.board-follow-state-indicator__label {
  color: rgba(226, 232, 240, 0.78);
  font-size: 12px;
  font-weight: 600;
  white-space: nowrap;
}

.board-follow-state-indicator__value {
  white-space: nowrap;
}

.board-follow-state-indicator.is-follow {
  border-color: rgba(34, 197, 94, 0.5);
  background: rgba(20, 83, 45, 0.88);
  color: #dcfce7;
}

.board-follow-state-indicator.is-free {
  border-color: rgba(59, 130, 246, 0.5);
  background: rgba(30, 64, 175, 0.88);
  color: #dbeafe;
}

.board-follow-state-indicator.is-unset,
.board-follow-state-indicator.is-loading {
  border-color: rgba(148, 163, 184, 0.45);
  background: rgba(51, 65, 85, 0.86);
  color: #e2e8f0;
}

.board-follow-state-indicator.is-error {
  border-color: rgba(248, 113, 113, 0.52);
  background: rgba(127, 29, 29, 0.88);
  color: #fee2e2;
}

@media (max-width: 768px) {
  .board-follow-state-indicator {
    right: 12px;
    bottom: 84px;
    max-width: min(300px, calc(100vw - 24px));
    padding: 7px 10px;
    font-size: 12px;
  }

  .board-follow-state-indicator__label {
    font-size: 11px;
  }
}

@media print {
  .board-follow-state-indicator {
    display: none !important;
  }
}

/* ------------------------------------------------------------
 * 画面同期ツールバー（Phase 17）
 * ------------------------------------------------------------ */
.tool-button--board-sync {
  border-color: rgba(56, 189, 248, 0.45);
}

.tool-button--board-sync.is-active {
  background: rgba(14, 165, 233, 0.24);
  border-color: rgba(125, 211, 252, 0.85);
  color: #e0f2fe;
}

.topbar-tool-panel--board-sync {
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.field-group--sync-control {
  align-items: center;
  gap: 8px;
}

.board-sync-switch {
  display: inline-flex;
  align-items: center;
  cursor: pointer;
  user-select: none;
}

.board-sync-switch-input {
  position: absolute;
  inline-size: 1px;
  block-size: 1px;
  opacity: 0;
  pointer-events: none;
}

.board-sync-switch-track {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  min-width: 146px;
  border: 1px solid rgba(148, 163, 184, 0.45);
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.75);
  overflow: hidden;
  box-shadow: inset 0 1px 2px rgba(15, 23, 42, 0.45);
}

.board-sync-switch-option {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  min-height: 30px;
  padding: 0 12px;
  font-size: 0.82rem;
  font-weight: 700;
  color: rgba(226, 232, 240, 0.72);
  transition: background 0.16s ease, color 0.16s ease;
}

.board-sync-switch-input:not(:checked) + .board-sync-switch-track .board-sync-switch-option--off {
  background: rgba(71, 85, 105, 0.92);
  color: #f8fafc;
}

.board-sync-switch-input:checked + .board-sync-switch-track .board-sync-switch-option--on {
  background: rgba(34, 197, 94, 0.88);
  color: #052e16;
}

.board-sync-switch-input:focus-visible + .board-sync-switch-track {
  outline: 2px solid rgba(125, 211, 252, 0.95);
  outline-offset: 2px;
}

.board-sync-switch-input:disabled + .board-sync-switch-track,
.checkbox-field--board-sync-full input:disabled + span,
.checkbox-field--board-sync-bulk input:disabled + span,
.checkbox-field--board-sync-full.is-disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

.checkbox-field--board-sync-bulk,
.checkbox-field--board-sync-full {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  border: 1px solid rgba(148, 163, 184, 0.35);
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.52);
  font-weight: 700;
}

.board-sync-toolbar-status {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.55);
  color: rgba(226, 232, 240, 0.86);
  font-size: 0.82rem;
}


/* ===== Blackboard status panel dock overlay fix 2026-05-06 =====
 * 状態パネルは通話パネルより手前に重ね、開閉ボタンは1つに統合します。
 * 通話パネル側CSSへ混ぜず、黒板状態パネルだけをここで扱います。
 */
.board-rightbar-layer > .right-status-panel,
.board-app.is-mobile-right-menu-open .board-rightbar-layer > .right-status-panel {
  z-index: 80 !important;
  background: rgba(0, 0, 0, 0.75) !important;
  border-color: rgba(255, 255, 255, 0.16) !important;
  box-shadow: 0 14px 34px rgba(0, 0, 0, 0.32) !important;
  backdrop-filter: none !important;
}

.board-rightbar-layer > .right-status-panel .right-status-panel__body,
.board-app.is-mobile-right-menu-open .board-rightbar-layer > .right-status-panel .right-status-panel__body {
  background: transparent !important;
}

.board-rightbar-layer > .right-status-panel .status-panel-box,
.board-app.is-mobile-right-menu-open .board-rightbar-layer > .right-status-panel .status-panel-box {
  background: rgba(0, 0, 0, 0.28) !important;
  border-color: rgba(255, 255, 255, 0.12) !important;
}

/* 状態パネルの開閉は右下の統合ボタンで行うため、パネル内の畳むボタンは使いません。 */
.right-status-panel__close {
  display: none !important;
}

/* 既存の開くボタンを、開閉兼用の小ボタンとして常時表示します。 */
.board-side-toggle,
.board-side-toggle.is-open {
  position: fixed !important;
  right: max(8px, env(safe-area-inset-right, 0px)) !important;
  bottom: max(10px, env(safe-area-inset-bottom, 0px)) !important;
  z-index: 2147482860 !important;
  display: grid !important;
  place-items: center !important;
  width: 30px !important;
  min-width: 30px !important;
  height: 30px !important;
  min-height: 30px !important;
  padding: 0 !important;
  border-radius: 999px !important;
  border: 1px solid rgba(255, 255, 255, 0.18) !important;
  background: rgba(0, 0, 0, 0.72) !important;
  color: rgba(255, 255, 255, 0.92) !important;
  font-size: 12px !important;
  font-weight: 800 !important;
  line-height: 1 !important;
  box-shadow: 0 8px 22px rgba(0, 0, 0, 0.3) !important;
  opacity: 1 !important;
  visibility: visible !important;
  pointer-events: auto !important;
}

.board-side-toggle.is-open {
  background: rgba(0, 0, 0, 0.84) !important;
  border-color: rgba(0, 250, 150, 0.32) !important;
}

@media (max-width: 960px) {
  .board-side-toggle,
  .board-side-toggle.is-open {
    right: max(8px, env(safe-area-inset-right, 0px)) !important;
    bottom: calc(max(10px, env(safe-area-inset-bottom, 0px)) + 2px) !important;
  }

  .board-mobile-zoom-panel {
    padding-right: 46px !important;
  }
}

@media (min-width: 961px) {
  .board-side-toggle,
  .board-side-toggle.is-open {
    right: 10px !important;
    bottom: 10px !important;
  }
}


/*
 * Phase status-panel-fix2: 状態パネルは初期閉じ、右下小ボタン1つで開閉します。
 * 通話パネルや黒板本体には触れず、状態パネル開閉UIだけを調整します。
 */
.board-side-toggle,
.board-side-toggle.is-open {
  right: max(3px, env(safe-area-inset-right, 0px)) !important;
  bottom: max(3px, env(safe-area-inset-bottom, 0px)) !important;
  z-index: 2147482860 !important;
  display: grid !important;
  place-items: center !important;
  width: 24px !important;
  min-width: 24px !important;
  height: 24px !important;
  min-height: 24px !important;
  padding: 0 !important;
  border-radius: 999px !important;
  font-size: 10px !important;
  line-height: 1 !important;
  letter-spacing: -0.08em !important;
  opacity: 0.92 !important;
  visibility: visible !important;
  pointer-events: auto !important;
}

.board-side-toggle.is-open {
  background: rgba(0, 0, 0, 0.84) !important;
  border-color: rgba(0, 250, 150, 0.32) !important;
}

@media (max-width: 960px) {
  .board-side-toggle,
  .board-side-toggle.is-open {
    right: max(2px, env(safe-area-inset-right, 0px)) !important;
    bottom: max(2px, env(safe-area-inset-bottom, 0px)) !important;
    width: 22px !important;
    min-width: 22px !important;
    height: 22px !important;
    min-height: 22px !important;
    font-size: 9px !important;
  }

  .board-mobile-zoom-panel {
    padding-right: 34px !important;
  }
}