/*
 * Geography model — neutral floating shell
 *
 * The compiled model bundle remains the source of truth for the scene,
 * teaching state, keyboard shortcuts and event handlers. This file owns the
 * presentation shell only: a full-viewport scene with floating, neutral glass
 * controls that keep the existing DOM contract intact.
 */

:root {
  --geo-ink: #070b10;
  --geo-ink-soft: #0d141b;
  --geo-surface: rgba(11, 17, 24, 0.72);
  --geo-surface-strong: rgba(12, 19, 27, 0.88);
  --geo-surface-soft: rgba(18, 27, 35, 0.5);
  --geo-surface-active: rgba(218, 239, 235, 0.14);
  --geo-surface-hover: rgba(232, 246, 243, 0.1);
  --geo-line: rgba(223, 240, 239, 0.18);
  --geo-line-strong: rgba(225, 247, 242, 0.34);
  --geo-line-soft: rgba(211, 235, 232, 0.1);
  --geo-text: #f2f7f6;
  --geo-text-soft: rgba(226, 238, 237, 0.74);
  --geo-text-muted: rgba(202, 218, 218, 0.55);
  --geo-mint: #c2e7dc;
  --geo-cyan: #69d8e4;
  --geo-warm: #f5be82;
  --geo-violet: #c3a7ff;
  --geo-shadow: 0 22px 70px rgba(0, 0, 0, 0.36);
  --geo-shadow-soft: 0 12px 34px rgba(0, 0, 0, 0.24);
  --geo-blur: blur(24px) saturate(122%);
  --geo-radius-lg: 24px;
  --geo-radius-md: 16px;
  --geo-radius-sm: 11px;
  --geo-ease: cubic-bezier(0.22, 0.75, 0.2, 1);
}

html,
body,
#root {
  width: 100%;
  min-width: 0;
  height: 100%;
  min-height: 100%;
  margin: 0;
  background: var(--geo-ink);
}

body {
  overflow: hidden;
  color: var(--geo-text);
  background:
    radial-gradient(circle at 74% 28%, rgba(88, 142, 150, 0.1), transparent 31rem),
    radial-gradient(circle at 18% 85%, rgba(91, 126, 115, 0.08), transparent 27rem),
    linear-gradient(135deg, #080c11 0%, #05080c 56%, #0b1217 100%);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Microsoft YaHei", sans-serif;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  font: inherit;
}

.app-root {
  position: relative;
  isolation: isolate;
  width: 100%;
  height: 100%;
  min-height: 100svh;
  overflow: hidden;
  background:
    radial-gradient(circle at 72% 43%, rgba(76, 130, 139, 0.08), transparent 34rem),
    linear-gradient(145deg, rgba(7, 12, 17, 0.44), rgba(4, 7, 11, 0.66));
}

.app-root::before,
.app-root::after {
  position: absolute;
  z-index: -1;
  inset: 0;
  content: "";
  pointer-events: none;
}

.app-root::before {
  background:
    linear-gradient(118deg, rgba(255, 255, 255, 0.025), transparent 28%, rgba(181, 224, 215, 0.025) 72%, transparent),
    radial-gradient(ellipse at 50% 110%, rgba(117, 178, 160, 0.06), transparent 52%);
}

.app-root::after {
  opacity: 0.32;
  background-image: linear-gradient(rgba(255, 255, 255, 0.018) 1px, transparent 1px), linear-gradient(90deg, rgba(255, 255, 255, 0.014) 1px, transparent 1px);
  background-size: 80px 80px;
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.72), transparent 70%);
}

/* Floating top toolbar. The external home anchor remains visible above it. */
.app-header {
  position: absolute;
  z-index: 40;
  top: max(16px, env(safe-area-inset-top));
  right: 20px;
  left: 20px;
  display: grid;
  min-height: 68px;
  grid-template-columns: minmax(250px, 1fr) auto auto auto auto;
  align-items: center;
  gap: 12px;
  padding: 12px 14px 12px 174px;
  border: 1px solid var(--geo-line);
  border-radius: 22px;
  color: var(--geo-text);
  background: linear-gradient(135deg, rgba(20, 29, 37, 0.78), rgba(8, 13, 19, 0.64));
  box-shadow: var(--geo-shadow-soft), inset 0 1px 0 rgba(255, 255, 255, 0.12), inset 0 -1px 0 rgba(177, 213, 208, 0.05);
  backdrop-filter: var(--geo-blur);
  -webkit-backdrop-filter: var(--geo-blur);
}

.app-header::after {
  position: absolute;
  top: 1px;
  right: 22px;
  left: 22px;
  height: 1px;
  border-radius: 999px;
  background: linear-gradient(90deg, transparent, rgba(246, 255, 252, 0.18), transparent);
  content: "";
  pointer-events: none;
}

.geography-return-home {
  position: fixed;
  z-index: 60;
  top: max(28px, calc(env(safe-area-inset-top) + 12px));
  left: max(34px, calc(env(safe-area-inset-left) + 14px));
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  gap: 7px;
  padding: 8px 13px;
  border: 1px solid rgba(231, 247, 243, 0.3);
  border-radius: 999px;
  color: rgba(246, 252, 251, 0.95);
  background: rgba(8, 14, 20, 0.55);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.18), 0 8px 22px rgba(0, 0, 0, 0.2);
  backdrop-filter: blur(18px) saturate(125%);
  -webkit-backdrop-filter: blur(18px) saturate(125%);
  font-size: 13px;
  font-weight: 680;
  line-height: 1;
  text-decoration: none;
  transition: transform 180ms var(--geo-ease), background 180ms ease, border-color 180ms ease;
}

.geography-return-home:hover,
.geography-return-home:focus-visible {
  border-color: rgba(231, 247, 243, 0.58);
  background: rgba(27, 43, 48, 0.74);
  outline: none;
  transform: translateY(-1px);
}

.app-title,
.app-version,
.app-subtitle,
.bug-feedback,
.teacher-guide-trigger,
.mobile-panel-toggle {
  position: relative;
  z-index: 1;
}

.app-title {
  min-width: 0;
  margin: 0;
  overflow: hidden;
  color: var(--geo-text);
  font-size: clamp(16px, 1.35vw, 22px);
  font-weight: 730;
  letter-spacing: -0.025em;
  line-height: 1.15;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.app-version {
  padding: 5px 8px;
  border: 1px solid var(--geo-line);
  border-radius: 999px;
  color: var(--geo-text-muted);
  background: rgba(255, 255, 255, 0.045);
  font-size: 10px;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.06em;
  white-space: nowrap;
}

.app-subtitle {
  color: var(--geo-text-muted);
  font-size: 11px;
  letter-spacing: 0.015em;
  white-space: nowrap;
}

.bug-feedback {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--geo-text-muted);
  font-size: 11px;
  white-space: nowrap;
}

.bug-feedback svg {
  color: var(--geo-warm);
}

.bug-feedback strong {
  color: rgba(245, 226, 201, 0.74);
  font-weight: 600;
}

.teacher-guide-trigger,
.mobile-panel-toggle {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 8px 12px;
  border: 1px solid var(--geo-line);
  border-radius: 12px;
  color: var(--geo-text-soft);
  background: rgba(238, 249, 246, 0.06);
  cursor: pointer;
  transition: transform 180ms var(--geo-ease), background 180ms ease, border-color 180ms ease, color 180ms ease;
}

.teacher-guide-trigger:hover,
.teacher-guide-trigger:focus-visible,
.mobile-panel-toggle:hover,
.mobile-panel-toggle:focus-visible {
  border-color: var(--geo-line-strong);
  color: var(--geo-text);
  background: rgba(232, 247, 243, 0.12);
  outline: none;
  transform: translateY(-1px);
}

.teacher-guide-trigger svg,
.mobile-panel-toggle svg {
  color: var(--geo-mint);
}

.mobile-panel-toggle {
  display: none;
}

/* Full-viewport scene: the panel floats above it instead of taking its width. */
.app-main {
  position: relative;
  width: 100%;
  height: 100%;
  min-height: 0;
  overflow: hidden;
}

.app-scene {
  position: absolute;
  z-index: 0;
  inset: 0;
  width: 100%;
  height: 100%;
  min-width: 0;
  min-height: 0;
  overflow: hidden;
  background: transparent;
}

.app-scene::before {
  position: absolute;
  z-index: 1;
  inset: 0;
  background: radial-gradient(ellipse at 55% 50%, transparent 20%, rgba(0, 0, 0, 0.16) 74%, rgba(0, 0, 0, 0.34));
  content: "";
  pointer-events: none;
}

.app-scene canvas {
  display: block;
  width: 100% !important;
  height: 100% !important;
  outline: none;
}

/* Shared floating surface language. */
.app-sidebar,
.scene-legend,
.section-lock-badge,
.textbook-mode-heading,
.subtropical-concept-overlay,
.subtropical-deflection-inset,
.concept-playback-controls,
.pressure-comparison-overlay,
.teacher-guide-dialog {
  border: 1px solid var(--geo-line);
  background: linear-gradient(140deg, rgba(20, 29, 37, 0.78), rgba(8, 13, 19, 0.7));
  box-shadow: var(--geo-shadow), inset 0 1px 0 rgba(255, 255, 255, 0.095), inset 0 -1px 0 rgba(183, 224, 215, 0.045);
  backdrop-filter: var(--geo-blur);
  -webkit-backdrop-filter: var(--geo-blur);
}

.app-sidebar {
  position: absolute;
  z-index: 25;
  top: 102px;
  bottom: 20px;
  left: 22px;
  display: block;
  width: min(352px, calc(100vw - 44px));
  max-height: calc(100% - 122px);
  padding: 18px;
  overflow-x: hidden;
  overflow-y: auto;
  border-radius: var(--geo-radius-lg);
  scrollbar-color: rgba(214, 235, 231, 0.24) transparent;
  scrollbar-width: thin;
}

.app-sidebar::before {
  position: absolute;
  top: 1px;
  right: 16px;
  left: 16px;
  height: 1px;
  border-radius: 999px;
  background: linear-gradient(90deg, transparent, rgba(242, 255, 252, 0.15), transparent);
  content: "";
  pointer-events: none;
}

.app-sidebar::-webkit-scrollbar {
  width: 5px;
}

.app-sidebar::-webkit-scrollbar-thumb {
  border-radius: 999px;
  background: rgba(215, 238, 234, 0.22);
}

.app-sidebar section,
.control-panel,
.lesson-steps {
  min-width: 0;
}

.panel-title {
  margin: 0;
  color: var(--geo-text);
  font-size: 12px;
  font-weight: 720;
  letter-spacing: 0.1em;
  line-height: 1.25;
  text-transform: uppercase;
}

.lesson-heading-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.lesson-heading-row > span {
  color: var(--geo-text-muted);
  font-size: 10px;
  white-space: nowrap;
}

.step-indicators {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 7px;
  margin-bottom: 13px;
}

.step-dot {
  display: grid;
  min-height: 34px;
  place-items: center;
  padding: 0;
  border: 1px solid var(--geo-line);
  border-radius: 10px;
  color: var(--geo-text-muted);
  background: rgba(232, 248, 244, 0.045);
  cursor: pointer;
  font-size: 12px;
  font-weight: 700;
  transition: transform 180ms var(--geo-ease), background 180ms ease, border-color 180ms ease, color 180ms ease;
}

.step-dot:hover,
.step-dot:focus-visible {
  border-color: var(--geo-line-strong);
  color: var(--geo-text);
  background: var(--geo-surface-hover);
  outline: none;
  transform: translateY(-1px);
}

.step-dot.active {
  border-color: rgba(208, 238, 229, 0.62);
  color: #07100f;
  background: linear-gradient(145deg, #d6eee6, #9fcfc5);
  box-shadow: 0 5px 16px rgba(142, 207, 193, 0.16), inset 0 1px 0 rgba(255, 255, 255, 0.66);
}

.step-dot.dimmed {
  opacity: 0.62;
}

.step-description {
  min-height: 164px;
  padding: 15px;
  border: 1px solid var(--geo-line-soft);
  border-radius: var(--geo-radius-md);
  background: linear-gradient(145deg, rgba(235, 249, 245, 0.075), rgba(7, 13, 18, 0.18));
}

.step-title {
  margin-bottom: 8px;
  color: var(--geo-text);
  font-size: 15px;
  font-weight: 740;
  letter-spacing: -0.015em;
  line-height: 1.35;
}

.step-text,
.step-teaching-cue p,
.thermal-notes li,
.subtropical-notes li,
.subtropical-notes > p,
.textbook-mode-note {
  color: var(--geo-text-soft);
  font-size: 12px;
  line-height: 1.72;
}

.step-text {
  margin: 0;
}

.step-text.muted {
  color: var(--geo-text-muted);
}

.step-teaching-cue {
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px solid var(--geo-line-soft);
}

.step-teaching-cue p {
  margin: 4px 0;
}

.step-teaching-cue strong {
  color: var(--geo-mint);
  font-weight: 650;
}

.step-nav {
  display: grid;
  grid-template-columns: 1fr 1.16fr 1fr;
  gap: 7px;
  margin-top: 11px;
}

.nav-btn,
.action-btn,
.reset-btn,
.concept-exit-btn,
.concept-demo-button,
.projection-toggle,
.view-mode-btn,
.season-btn,
.toggle-btn,
.circulation-focus-control button,
.concept-playback-controls button,
.pressure-cause-card button,
.teacher-guide-start,
.teacher-guide-secondary {
  appearance: none;
  border: 1px solid var(--geo-line);
  border-radius: var(--geo-radius-sm);
  color: var(--geo-text-soft);
  background: rgba(231, 247, 244, 0.055);
  cursor: pointer;
  transition: transform 180ms var(--geo-ease), background 180ms ease, border-color 180ms ease, color 180ms ease, box-shadow 180ms ease;
}

.nav-btn,
.action-btn,
.reset-btn,
.concept-exit-btn,
.projection-toggle,
.concept-demo-button,
.teacher-guide-start,
.teacher-guide-secondary {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 8px 10px;
  font-size: 11px;
  font-weight: 650;
}

.nav-btn:hover:not(:disabled),
.nav-btn:focus-visible:not(:disabled),
.action-btn:hover:not(:disabled),
.action-btn:focus-visible:not(:disabled),
.reset-btn:hover:not(:disabled),
.reset-btn:focus-visible:not(:disabled),
.concept-exit-btn:hover:not(:disabled),
.concept-exit-btn:focus-visible:not(:disabled),
.concept-demo-button:hover:not(:disabled),
.concept-demo-button:focus-visible:not(:disabled),
.projection-toggle:hover:not(:disabled),
.projection-toggle:focus-visible:not(:disabled),
.view-mode-btn:hover:not(:disabled),
.view-mode-btn:focus-visible:not(:disabled),
.season-btn:hover:not(:disabled),
.season-btn:focus-visible:not(:disabled),
.toggle-btn:hover:not(:disabled),
.toggle-btn:focus-visible:not(:disabled),
.circulation-focus-control button:hover:not(:disabled),
.circulation-focus-control button:focus-visible:not(:disabled),
.concept-playback-controls button:hover:not(:disabled),
.concept-playback-controls button:focus-visible:not(:disabled),
.pressure-cause-card button:hover:not(:disabled),
.pressure-cause-card button:focus-visible:not(:disabled),
.teacher-guide-start:hover:not(:disabled),
.teacher-guide-start:focus-visible:not(:disabled),
.teacher-guide-secondary:hover:not(:disabled),
.teacher-guide-secondary:focus-visible:not(:disabled) {
  border-color: var(--geo-line-strong);
  color: var(--geo-text);
  background: rgba(232, 248, 244, 0.12);
  outline: none;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.1);
  transform: translateY(-1px);
}

button:focus-visible,
a:focus-visible {
  outline: 2px solid rgba(203, 239, 229, 0.78);
  outline-offset: 3px;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.38;
}

.nav-btn {
  min-width: 0;
  padding-inline: 5px;
}

.sidebar-section-divider {
  height: 1px;
  margin: 18px 0;
  background: linear-gradient(90deg, transparent, var(--geo-line), transparent);
}

.control-panel {
  display: grid;
  gap: 10px;
}

.control-panel > .panel-title:not(:first-child) {
  margin-top: 10px;
}

.view-mode-control,
.season-control {
  display: grid;
  gap: 6px;
}

.view-mode-control {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.season-control {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.view-mode-btn,
.season-btn {
  display: inline-flex;
  min-height: 37px;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 7px 6px;
  font-size: 11px;
  font-weight: 640;
}

.view-mode-btn svg,
.season-btn svg,
.projection-toggle svg,
.concept-demo-button svg,
.reset-btn svg {
  color: var(--geo-text-muted);
  flex: 0 0 auto;
}

.view-mode-btn.active,
.season-btn.active,
.projection-toggle.active,
.concept-demo-button.active,
.toggle-btn.active,
.circulation-focus-control button.active,
.concept-speed-control button.active {
  border-color: rgba(211, 240, 232, 0.48);
  color: var(--geo-text);
  background: linear-gradient(145deg, rgba(211, 239, 232, 0.19), rgba(142, 190, 181, 0.09));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.13), 0 5px 18px rgba(89, 152, 139, 0.08);
}

.view-mode-btn.active svg,
.season-btn.active svg,
.projection-toggle.active svg,
.concept-demo-button.active svg {
  color: var(--geo-mint);
}

.textbook-mode-note {
  margin: -2px 0 2px;
  padding: 9px 10px;
  border-left: 2px solid rgba(201, 207, 255, 0.6);
  color: rgba(224, 226, 255, 0.72);
  background: rgba(167, 172, 255, 0.055);
}

.projection-toggle {
  width: 100%;
}

.circulation-focus-control {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 6px;
}

.circulation-focus-control button {
  min-height: 34px;
  padding: 6px 4px;
  font-size: 11px;
  font-weight: 650;
}

.concept-demo-button {
  justify-content: flex-start;
  width: 100%;
  text-align: left;
}

.concept-demo-button svg {
  color: var(--geo-warm);
}

.polar-front-button svg {
  color: var(--geo-cyan);
}

.pressure-comparison-button svg {
  color: var(--geo-violet);
}

.toggle-list {
  display: grid;
  gap: 5px;
}

.toggle-btn {
  display: grid;
  min-height: 35px;
  grid-template-columns: 10px minmax(0, 1fr) auto;
  align-items: center;
  gap: 8px;
  padding: 6px 9px;
  text-align: left;
}

.toggle-indicator {
  width: 7px;
  height: 7px;
  border: 1px solid rgba(223, 239, 236, 0.4);
  border-radius: 50%;
  background: transparent;
  box-shadow: 0 0 0 2px rgba(218, 242, 237, 0.025);
}

.toggle-btn.active .toggle-indicator {
  border-color: var(--geo-mint);
  background: var(--geo-mint);
  box-shadow: 0 0 0 3px rgba(194, 231, 220, 0.1);
}

.toggle-label {
  min-width: 0;
  color: var(--geo-text-soft);
  font-size: 11px;
}

.toggle-shortcut {
  min-width: 18px;
  color: var(--geo-text-muted);
  font-size: 10px;
  text-align: center;
}

.panel-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

.action-btn.secondary {
  min-height: 33px;
  color: var(--geo-text-muted);
  font-size: 10px;
}

.reset-btn {
  width: 100%;
  margin-top: 3px;
}

/* Context notes use the same surface hierarchy as the lesson panel. */
.thermal-notes,
.subtropical-notes {
  padding: 2px 2px 0;
}

.thermal-notes ol,
.subtropical-notes ol {
  display: grid;
  gap: 8px;
  margin: 14px 0 0;
  padding-left: 20px;
}

.thermal-notes li,
.subtropical-notes li {
  padding-left: 3px;
}

.thermal-notes li::marker,
.subtropical-notes li::marker {
  color: var(--geo-mint);
  font-weight: 700;
}

.subtropical-notes li {
  transition: color 180ms ease, opacity 180ms ease;
}

.subtropical-notes li:not(.active) {
  color: var(--geo-text-muted);
}

.subtropical-notes li.active {
  color: var(--geo-text);
}

.subtropical-notes > p {
  margin: 14px 0 0;
  padding: 10px 11px;
  border: 1px solid var(--geo-line-soft);
  border-radius: var(--geo-radius-sm);
  color: var(--geo-text-soft);
  background: rgba(245, 190, 130, 0.06);
}

.polar-front-notes > p {
  background: rgba(105, 216, 228, 0.055);
}

.concept-exit-btn {
  width: 100%;
  margin-top: 12px;
}

/* Scene status, legend and lock labels are informative overlays, not a new sidebar. */
.section-lock-badge,
.textbook-mode-heading,
.scene-legend {
  position: absolute;
  z-index: 12;
  pointer-events: none;
}

.section-lock-badge {
  top: 104px;
  right: 24px;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 9px 12px;
  border-radius: 999px;
  color: var(--geo-text-soft);
  font-size: 11px;
  font-weight: 650;
}

.section-lock-badge svg {
  color: var(--geo-mint);
}

.textbook-mode-heading {
  top: 106px;
  left: 50%;
  display: grid;
  gap: 3px;
  padding: 10px 14px;
  border-radius: var(--geo-radius-sm);
  color: var(--geo-text);
  text-align: center;
  transform: translateX(-50%);
}

.textbook-mode-heading strong {
  font-size: 13px;
  font-weight: 720;
}

.textbook-mode-heading span {
  color: var(--geo-text-muted);
  font-size: 10px;
}

.scene-legend {
  right: 24px;
  bottom: 24px;
  display: grid;
  min-width: 168px;
  gap: 8px;
  padding: 13px 14px;
  border-radius: var(--geo-radius-md);
}

.legend-title {
  color: var(--geo-text-muted);
  font-size: 10px;
  font-weight: 720;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.legend-row {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--geo-text-soft);
  font-size: 11px;
}

.legend-swatch,
.legend-arrow {
  flex: 0 0 auto;
}

.legend-swatch {
  width: 9px;
  height: 9px;
  border-radius: 50%;
}

/* Concept demonstrations float over the scene and keep their scientific tint. */
.subtropical-concept-overlay {
  position: absolute;
  z-index: 18;
  top: 104px;
  left: 50%;
  display: grid;
  width: min(700px, calc(100% - 440px));
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 7px;
  padding: 8px;
  border-radius: var(--geo-radius-md);
  transform: translateX(-50%);
}

.subtropical-concept-overlay button {
  display: grid;
  min-height: 50px;
  place-items: center;
  gap: 3px;
  padding: 7px 6px;
  border: 1px solid var(--geo-line);
  border-radius: 10px;
  color: var(--geo-text-muted);
  background: rgba(231, 247, 244, 0.045);
  cursor: pointer;
  font-size: 10px;
  line-height: 1.25;
  text-align: center;
  transition: background 180ms ease, border-color 180ms ease, color 180ms ease, transform 180ms var(--geo-ease);
}

.subtropical-concept-overlay button b {
  color: var(--geo-warm);
  font-size: 14px;
}

.subtropical-concept-overlay button:hover,
.subtropical-concept-overlay button:focus-visible,
.subtropical-concept-overlay button.active {
  border-color: rgba(245, 190, 130, 0.55);
  color: var(--geo-text);
  background: rgba(245, 190, 130, 0.12);
  outline: none;
  transform: translateY(-1px);
}

.polar-front-overlay button b {
  color: var(--geo-cyan);
}

.polar-front-overlay button:hover,
.polar-front-overlay button:focus-visible,
.polar-front-overlay button.active {
  border-color: rgba(105, 216, 228, 0.52);
  background: rgba(105, 216, 228, 0.1);
}

.subtropical-deflection-inset {
  position: absolute;
  z-index: 17;
  bottom: 26px;
  left: 398px;
  width: min(220px, 18vw);
  padding: 9px;
  border-radius: var(--geo-radius-md);
  opacity: 0.94;
}

.subtropical-deflection-inset svg,
.polar-front-inset svg {
  display: block;
  width: 100%;
  height: auto;
}

.concept-playback-controls {
  position: absolute;
  z-index: 21;
  bottom: 24px;
  left: 50%;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px;
  border-radius: 999px;
  transform: translateX(-50%);
}

.concept-playback-controls > button,
.concept-speed-control button {
  display: inline-flex;
  min-width: 32px;
  min-height: 30px;
  align-items: center;
  justify-content: center;
  gap: 5px;
  padding: 5px 8px;
  border-radius: 9px;
  font-size: 10px;
}

.concept-play-toggle {
  min-width: 62px !important;
}

.concept-speed-control {
  display: inline-flex;
  gap: 3px;
  padding: 3px;
  border: 1px solid var(--geo-line-soft);
  border-radius: 10px;
  background: rgba(0, 0, 0, 0.12);
}

.concept-stage-status {
  min-width: 49px;
  color: var(--geo-text-muted);
  font-size: 10px;
  text-align: center;
}

/* Pressure comparison remains a true modal, with neutral chrome and semantic colors. */
.pressure-comparison-overlay {
  position: absolute;
  z-index: 70;
  inset: 112px 24px 24px;
  display: grid;
  grid-template-rows: auto auto 1fr auto;
  gap: 14px;
  padding: 20px;
  overflow: auto;
  border-radius: var(--geo-radius-lg);
}

.pressure-comparison-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
}

.pressure-comparison-header > div > span {
  color: var(--geo-violet);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.12em;
}

.pressure-comparison-header h2 {
  margin: 5px 0 0;
  color: var(--geo-text);
  font-size: clamp(20px, 2.2vw, 30px);
  letter-spacing: -0.04em;
}

.pressure-comparison-header > button {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  border: 1px solid var(--geo-line);
  border-radius: 50%;
  color: var(--geo-text-soft);
  background: rgba(232, 247, 244, 0.06);
  cursor: pointer;
}

.pressure-cause-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  color: var(--geo-text-muted);
  font-size: 11px;
}

.pressure-cause-legend span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.pressure-cause-grid {
  display: grid;
  min-height: 0;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 9px;
}

.pressure-cause-card {
  display: flex;
  min-width: 0;
  flex-direction: column;
  gap: 9px;
  padding: 13px;
  border: 1px solid var(--geo-line-soft);
  border-radius: var(--geo-radius-md);
  background: rgba(5, 10, 15, 0.28);
}

.pressure-cause-card.thermal {
  box-shadow: inset 0 2px 0 rgba(245, 190, 130, 0.34);
}

.pressure-cause-card.dynamic {
  box-shadow: inset 0 2px 0 rgba(105, 216, 228, 0.3);
}

.pressure-cause-card-top {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: start;
  gap: 9px;
}

.pressure-cause-card-top > b {
  color: var(--geo-text-muted);
  font-size: 12px;
}

.pressure-cause-card-top h3 {
  margin: 0;
  color: var(--geo-text);
  font-size: 13px;
}

.pressure-cause-card-top span {
  color: var(--geo-text-muted);
  font-size: 10px;
}

.pressure-cause-card-top i {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  font-size: 10px;
  font-style: normal;
  white-space: nowrap;
}

.pressure-cause-card-top i.high {
  color: var(--geo-cyan);
}

.pressure-cause-card-top i.low {
  color: var(--geo-warm);
}

.pressure-cause-animation {
  min-height: 88px;
  border: 1px solid var(--geo-line-soft);
  border-radius: 10px;
  background: rgba(0, 0, 0, 0.12);
}

.pressure-cause-card p,
.pressure-cause-card strong {
  margin: 0;
  color: var(--geo-text-soft);
  font-size: 11px;
  line-height: 1.55;
}

.pressure-cause-card strong {
  color: var(--geo-text);
  font-weight: 650;
}

.pressure-cause-card button {
  min-height: 30px;
  margin-top: auto;
  padding: 5px 8px;
  font-size: 10px;
}

.pressure-comparison-summary {
  padding-top: 12px;
  border-top: 1px solid var(--geo-line-soft);
  color: var(--geo-text-muted);
  font-size: 11px;
}

.pressure-comparison-summary b {
  color: var(--geo-mint);
}

/* Teacher guide modal. */
.teacher-guide-backdrop {
  position: fixed;
  z-index: 100;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 24px;
  background: rgba(2, 5, 8, 0.58);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.teacher-guide-dialog {
  position: relative;
  width: min(720px, 100%);
  max-height: min(760px, calc(100svh - 48px));
  overflow: auto;
  border-radius: var(--geo-radius-lg);
}

.teacher-guide-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  padding: 22px 24px 12px;
}

.teacher-guide-kicker {
  color: var(--geo-mint);
  font-size: 10px;
  font-weight: 720;
  letter-spacing: 0.13em;
}

.teacher-guide-header h2 {
  margin: 5px 0 0;
  color: var(--geo-text);
  font-size: 24px;
  letter-spacing: -0.04em;
}

.teacher-guide-close {
  display: grid;
  width: 35px;
  height: 35px;
  place-items: center;
  border: 1px solid var(--geo-line);
  border-radius: 50%;
  color: var(--geo-text-soft);
  background: rgba(232, 247, 244, 0.06);
  cursor: pointer;
}

.teacher-guide-content {
  display: grid;
  gap: 14px;
  padding: 0 24px 20px;
}

.teacher-guide-content p,
.teacher-route-list li,
.teacher-warning-list li,
.teacher-shortcuts li {
  color: var(--geo-text-soft);
  font-size: 12px;
  line-height: 1.7;
}

.teacher-core-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.teacher-core-grid > section,
.teacher-shortcuts,
.teacher-warning-list,
.teacher-route-list {
  padding: 13px;
  border: 1px solid var(--geo-line-soft);
  border-radius: var(--geo-radius-md);
  background: rgba(232, 247, 244, 0.035);
}

.teacher-guide-content h3 {
  margin: 0 0 7px;
  color: var(--geo-text);
  font-size: 12px;
}

.teacher-guide-content ul,
.teacher-guide-content ol {
  margin: 0;
  padding-left: 20px;
}

.teacher-guide-footer {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  padding: 15px 24px 20px;
  border-top: 1px solid var(--geo-line-soft);
}

/* Mobile drawer: no feature is removed; the same panel becomes a scrollable sheet. */
.mobile-panel-backdrop {
  position: absolute;
  z-index: 22;
  inset: 0;
  display: block;
  border: 0;
  background: rgba(1, 5, 8, 0.48);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition: opacity 220ms ease;
}

.mobile-panel-backdrop.visible {
  opacity: 1;
  pointer-events: auto;
}

@media (max-width: 1260px) {
  .app-header {
    grid-template-columns: minmax(210px, 1fr) auto auto auto;
  }

  .app-subtitle {
    display: none;
  }

  .app-sidebar {
    width: 326px;
  }

  .subtropical-concept-overlay {
    width: min(630px, calc(100% - 410px));
  }
}

@media (max-width: 900px) and (min-width: 761px) {
  .app-header {
    left: 14px;
    right: 14px;
    padding-left: 156px;
  }

  .app-sidebar {
    top: 98px;
    bottom: 14px;
    left: 14px;
    width: 294px;
    padding: 15px;
  }

  .subtropical-concept-overlay {
    left: calc(50% + 110px);
    width: min(500px, calc(100% - 340px));
  }

  .subtropical-deflection-inset {
    left: 324px;
    width: 150px;
  }

  .scene-legend {
    right: 14px;
    bottom: 14px;
  }
}

@media (max-width: 760px) {
  .app-header {
    top: max(10px, env(safe-area-inset-top));
    right: 10px;
    left: 10px;
    min-height: 54px;
    grid-template-columns: minmax(0, 1fr) auto auto auto;
    gap: 6px;
    padding: 8px 8px 8px 110px;
    border-radius: 18px;
  }

  .geography-return-home {
    top: max(18px, calc(env(safe-area-inset-top) + 8px));
    left: max(18px, calc(env(safe-area-inset-left) + 8px));
    min-height: 32px;
    padding: 7px 9px;
    font-size: 11px;
  }

  .app-title {
    font-size: 14px;
  }

  .app-version {
    padding: 4px 6px;
    font-size: 9px;
  }

  .bug-feedback {
    position: absolute;
    top: calc(100% + 6px);
    right: 70px;
    padding: 4px 7px;
    border: 1px solid var(--geo-line-soft);
    border-radius: 999px;
    background: rgba(8, 14, 20, 0.58);
    font-size: 9px;
  }

  .bug-feedback strong {
    display: inline;
  }

  .teacher-guide-trigger,
  .mobile-panel-toggle {
    min-width: 34px;
    min-height: 34px;
    padding: 6px;
  }

  .teacher-guide-trigger span {
    position: absolute;
    width: 1px;
    height: 1px;
    margin: -1px;
    padding: 0;
    overflow: hidden;
    border: 0;
    clip: rect(0 0 0 0);
    white-space: nowrap;
  }

  .mobile-panel-toggle {
    display: inline-flex;
  }

  .app-sidebar {
    top: auto;
    right: 10px;
    bottom: max(10px, env(safe-area-inset-bottom));
    left: 10px;
    width: auto;
    max-height: min(76svh, 630px);
    padding: 16px;
    border-radius: 25px;
    transform: translateY(calc(100% + 24px));
    transition: transform 260ms var(--geo-ease), opacity 180ms ease;
    opacity: 0;
    pointer-events: none;
  }

  .app-sidebar.mobile-open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .app-sidebar::after {
    display: block;
    width: 42px;
    height: 4px;
    margin: -6px auto 13px;
    border-radius: 999px;
    background: rgba(223, 243, 239, 0.3);
    content: "";
  }

  .app-scene::before {
    background: radial-gradient(ellipse at 50% 48%, transparent 18%, rgba(0, 0, 0, 0.2) 78%, rgba(0, 0, 0, 0.36));
  }

  .section-lock-badge {
    top: 80px;
    right: 12px;
    padding: 7px 9px;
    font-size: 9px;
  }

  .textbook-mode-heading {
    top: 80px;
    left: 50%;
    max-width: calc(100% - 24px);
    padding: 8px 10px;
  }

  .textbook-mode-heading strong {
    font-size: 11px;
  }

  .subtropical-concept-overlay {
    top: 80px;
    right: 10px;
    left: 10px;
    width: auto;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    transform: none;
  }

  .subtropical-concept-overlay button {
    min-height: 44px;
  }

  .subtropical-deflection-inset {
    right: 10px;
    bottom: 90px;
    left: auto;
    width: 142px;
  }

  .concept-playback-controls {
    right: 10px;
    bottom: max(12px, env(safe-area-inset-bottom));
    left: 10px;
    justify-content: center;
    transform: none;
  }

  .scene-legend {
    right: 12px;
    bottom: 14px;
    min-width: 142px;
    padding: 10px 11px;
  }

  .pressure-comparison-overlay {
    inset: 76px 10px 10px;
    gap: 12px;
    padding: 15px;
    border-radius: 21px;
  }

  .pressure-cause-grid {
    grid-template-columns: 1fr;
  }

  .pressure-cause-card {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(120px, 0.7fr);
    align-items: start;
  }

  .pressure-cause-card-top,
  .pressure-cause-card p,
  .pressure-cause-card strong,
  .pressure-cause-card > button {
    grid-column: 1;
  }

  .pressure-cause-animation {
    grid-column: 2;
    grid-row: 1 / span 4;
  }

  .teacher-guide-backdrop {
    padding: 12px;
  }

  .teacher-guide-header,
  .teacher-guide-content,
  .teacher-guide-footer {
    padding-right: 16px;
    padding-left: 16px;
  }

  .teacher-guide-header h2 {
    font-size: 20px;
  }

  .teacher-core-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 420px) {
  .app-header {
    padding-left: 105px;
  }

  .app-title {
    font-size: 12px;
  }

  .bug-feedback {
    right: 58px;
    max-width: 164px;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .step-nav {
    grid-template-columns: 1fr 1fr;
  }

  .step-nav .nav-btn:nth-child(2) {
    grid-column: 1 / -1;
    grid-row: 1;
  }

  .step-nav .nav-btn:first-child {
    grid-column: 1;
    grid-row: 2;
  }

  .step-nav .nav-btn:last-child {
    grid-column: 2;
    grid-row: 2;
  }

  .concept-playback-controls {
    gap: 3px;
    padding: 5px;
  }

  .concept-playback-controls > button,
  .concept-speed-control button {
    min-width: 28px;
    padding-inline: 5px;
  }

  .concept-play-toggle {
    min-width: 54px !important;
  }

  .concept-stage-status {
    min-width: 42px;
    font-size: 9px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}

@media (prefers-reduced-transparency: reduce) {
  .app-header,
  .app-sidebar,
  .scene-legend,
  .section-lock-badge,
  .textbook-mode-heading,
  .subtropical-concept-overlay,
  .subtropical-deflection-inset,
  .concept-playback-controls,
  .pressure-comparison-overlay,
  .teacher-guide-dialog {
    background: var(--geo-surface-strong);
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
  }
}