html {
  box-sizing: border-box;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

*,
*::before,
*::after {
  box-sizing: inherit;
}

body {
  overflow-x: hidden;
}

img,
svg,
video,
canvas,
iframe {
  max-width: 100%;
}

img,
svg,
video,
canvas {
  height: auto;
}

iframe {
  border: 0;
}

table {
  max-width: 100%;
}

th,
td,
p,
li,
h1,
h2,
h3,
h4,
button,
a,
label,
textarea,
input {
  overflow-wrap: anywhere;
}

button,
[role="button"],
input,
select,
textarea,
a {
  touch-action: manipulation;
}

button,
.button,
.btn,
.nav-btn,
.logout-btn,
.start-btn,
.topic-btn,
.subject-pill,
.small-chip,
.action-btn,
.primary-btn,
.secondary-btn,
.option-btn,
.sort-item,
.tab-link,
.direction-card,
.continent-card,
.ocean-label-card,
.drag-card,
.drag-item,
.meaning-card,
.choice-card,
.material-card,
.state-card,
.province-card,
.symbol-card,
.map-type-card {
  min-height: 44px;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible,
[tabindex]:focus-visible {
  outline: 4px solid rgba(47, 111, 228, 0.35);
  outline-offset: 3px;
}

button:disabled,
[aria-disabled="true"],
.disabled,
.locked {
  cursor: not-allowed !important;
  pointer-events: none;
  opacity: 0.58;
  filter: grayscale(0.25);
}

.video-frame,
.video-wrap,
.video-container,
.responsive-video {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
}

.video-frame iframe,
.video-wrap iframe,
.video-container iframe,
.responsive-video iframe {
  display: block;
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.table-wrap {
  width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.table-wrap table {
  min-width: 560px;
}

.mobile-drag-selected {
  outline: 4px solid rgba(245, 158, 11, 0.45) !important;
  outline-offset: 3px;
  transform: translateY(-1px);
}

.mobile-drop-ready {
  box-shadow: 0 0 0 4px rgba(47, 111, 228, 0.18) !important;
}

.mobile-touch-tip {
  margin-top: 10px;
  padding: 10px 12px;
  border: 2px dashed rgba(47, 111, 228, 0.32);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.78);
  color: #334155;
  font-size: 0.95rem;
  font-weight: 800;
}

@media (hover: none) {
  .nav-btn:active,
  .logout-btn:active,
  .start-btn:active,
  .topic-btn:active,
  .action-btn:active,
  .primary-btn:active,
  .secondary-btn:active,
  .option-btn:active,
  .sort-item:active,
  .tab-link:active,
  .direction-card:active,
  .continent-card:active,
  .ocean-label-card:active,
  .drag-card:active,
  .drag-item:active,
  .meaning-card:active,
  .choice-card:active {
    transform: translateY(1px);
  }
}

@media (max-width: 900px) {
  body {
    font-size: 17px;
  }

  .top-banner,
  .app-header {
    padding: 22px 20px !important;
  }

  .banner-inner,
  .header-inner,
  .quick-nav,
  .quick-tabs,
  .welcome-card,
  .hero-card,
  .subject-grid,
  .topic-grid,
  .dashboard-grid,
  .card-grid,
  .section-grid,
  .notes-list,
  .grid-2,
  .grid-3,
  .practice-layout,
  .sort-area,
  .sim-layout,
  .cycle-sim-layout,
  .tester,
  .think-grid,
  .finish-stats {
    grid-template-columns: 1fr !important;
  }

  .header-actions,
  .nav-actions,
  .tab-row,
  .pill-row,
  .button-row,
  .exercise-actions,
  .round-tabs,
  .tabs {
    justify-content: flex-start !important;
  }

  .page-shell,
  .main-wrap {
    width: 100% !important;
    padding-left: 18px !important;
    padding-right: 18px !important;
  }

  .content-section,
  .hero-card,
  .welcome-card,
  .nav-panel,
  .tab-panel,
  .quiz-card,
  .activity-panel,
  .info-card {
    border-radius: 18px !important;
  }

  .option-grid,
  .options,
  .direction-bank,
  .item-bank,
  .targets,
  .match-targets,
  .keyword-grid {
    grid-template-columns: 1fr 1fr !important;
  }

  .sort-item,
  .option-btn,
  .action-btn,
  .primary-btn,
  .secondary-btn,
  .nav-btn,
  .topic-btn {
    padding: 12px 14px;
  }
}

@media (max-width: 600px) {
  body {
    font-size: 16px;
  }

  .top-banner,
  .app-header {
    padding: 18px 14px !important;
  }

  .banner-inner,
  .header-inner,
  .top-bar,
  .brand,
  .section-header {
    align-items: flex-start !important;
  }

  .top-bar,
  .brand,
  .header-actions,
  .nav-actions,
  .tab-row,
  .pill-row,
  .button-row,
  .exercise-actions,
  .round-tabs,
  .tabs {
    flex-direction: column !important;
    width: 100%;
  }

  .header-actions > *,
  .nav-actions > *,
  .tab-row > *,
  .pill-row > *,
  .button-row > *,
  .exercise-actions > *,
  .round-tabs > *,
  .tabs > *,
  .logout-btn,
  .start-btn {
    width: 100%;
  }

  .nav-btn,
  .topic-btn,
  .action-btn,
  .primary-btn,
  .secondary-btn,
  .option-btn,
  .tab-link,
  .sort-item {
    justify-content: center;
    text-align: center;
  }

  .page-shell,
  .main-wrap {
    padding: 16px 12px 30px !important;
  }

  .content-section,
  .hero-card,
  .welcome-card,
  .nav-panel,
  .tab-panel,
  .quiz-card,
  .activity-panel,
  .info-card,
  .note-card {
    padding: 16px !important;
    border-radius: 16px !important;
  }

  h1 {
    font-size: clamp(1.8rem, 10vw, 2.5rem) !important;
    letter-spacing: 0 !important;
  }

  h2 {
    font-size: clamp(1.45rem, 7vw, 2rem) !important;
    letter-spacing: 0 !important;
  }

  h3 {
    font-size: clamp(1.15rem, 5vw, 1.45rem) !important;
  }

  .crest-wrap,
  .school-logo-box,
  .brand-icon {
    width: 64px !important;
    height: 64px !important;
    border-radius: 16px !important;
  }

  .option-grid,
  .options,
  .direction-bank,
  .item-bank,
  .targets,
  .match-targets,
  .keyword-grid,
  .finish-stats {
    grid-template-columns: 1fr !important;
  }

  .item-bank {
    display: grid !important;
  }

  .sort-item,
  .direction-card,
  .continent-card,
  .ocean-label-card,
  .drag-card,
  .drag-item,
  .meaning-card,
  .choice-card {
    width: 100% !important;
    min-width: 0 !important;
    white-space: normal !important;
  }

  .compass-stage,
  .map-stage,
  .continent-map,
  .ocean-map,
  .diagram-practice-stage,
  .cycle-scene,
  .water-scene,
  .test-scene {
    min-height: min(520px, 115vw) !important;
  }

  .drop-point,
  .continent-drop,
  .ocean-drop-zone,
  .province-zone,
  .capital-zone,
  .ocean-zone {
    min-width: 76px !important;
    width: auto !important;
    max-width: 34vw !important;
    min-height: 38px !important;
    padding: 5px !important;
    font-size: 0.72rem !important;
    line-height: 1.15 !important;
  }

  .drop-zone,
  .bin {
    min-height: 44px !important;
    padding: 8px !important;
    line-height: 1.2 !important;
  }

  textarea,
  input,
  select {
    font-size: 16px !important;
  }
}

@media (min-width: 901px) {
  .page-shell,
  .main-wrap,
  .banner-inner,
  .header-inner {
    max-width: min(1220px, calc(100vw - 48px));
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}