/* === Mobile Breakpoints === */

/* ── Tablet & small desktop (768px) ── */
@media (max-width: 768px) {
  :root {
    --content-width: 100%;
  }

  /* Header */
  #app-header {
    padding: 0.75rem 1rem;
    padding-top: max(0.75rem, env(safe-area-inset-top));
    padding-left: max(1rem, env(safe-area-inset-left));
    padding-right: max(1rem, env(safe-area-inset-right));
  }

  .nav-brand {
    font-size: 1.1rem;
  }

  .nav-links {
    gap: 1rem;
  }

  .nav-link {
    font-size: 0.8rem;
    padding: 0.35rem 0.25rem; /* bigger touch target */
  }

  #app-content {
    padding-top: 4rem;
  }

  .screen {
    padding: 1.5rem 1rem 3rem;
    padding-bottom: max(3rem, env(safe-area-inset-bottom));
  }

  /* Landing */
  .landing-title {
    font-size: 2.5rem;
  }

  .landing-subtitle {
    font-size: 1rem;
  }

  .landing-desc {
    font-size: 0.85rem;
  }

  .landing-content .btn {
    width: 100%;
    justify-content: center;
  }

  /* Chapter */
  .chapter-heading {
    font-size: 1.5rem;
  }

  .chapter-content {
    gap: 1.25rem;
  }

  .block-scene {
    font-size: 1rem;
  }

  .block-scene,
  .block-observation,
  .block-analogy,
  .block-key-concept {
    padding: 1rem 1.25rem;
  }

  .block-interactive {
    padding: 1.25rem 0.75rem;
  }

  .block-question {
    font-size: 1.15rem;
  }

  .block-explanation {
    font-size: 0.95rem;
  }

  /* Quiz — touch-friendly targets */
  .quiz-question {
    font-size: 1.05rem;
  }

  .quiz-option {
    padding: 0.9rem 1rem;
    font-size: 0.95rem;
    min-height: 44px;
  }

  /* Chapter nav */
  .chapter-navigation {
    flex-direction: row;
    gap: 0.75rem;
  }

  .chapter-navigation .btn {
    flex: 1;
    justify-content: center;
    min-height: 44px;
  }

  .btn {
    padding: 0.65rem 1.25rem;
    font-size: 0.9rem;
    min-height: 44px; /* touch target */
  }

  /* Graph */
  #graph-container {
    height: 400px;
    border-radius: var(--radius-md);
  }

  /* Chapter cards */
  .chapter-card {
    padding: 1rem 1.25rem;
    gap: 1rem;
    min-height: 56px;
  }

  .chapter-card-num {
    font-size: 1.25rem;
    min-width: 2rem;
  }

  .chapter-card-info h3 {
    font-size: 0.95rem;
  }

  .chapter-card-info p {
    font-size: 0.8rem;
  }

  /* Topic Picker */
  .topic-grid {
    gap: 1rem;
    margin-top: 1.5rem;
  }

  .topic-card {
    padding: 1.25rem;
    gap: 1rem;
  }

  .topic-icon {
    font-size: 2rem;
  }

  .topic-title {
    font-size: 1.1rem;
  }

  .topic-seed {
    font-size: 0.85rem;
  }

  .topic-seed-desc {
    font-size: 0.8rem;
  }

  /* Interactive widgets */
  .amber-scene {
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
  }

  .compass-scene {
    gap: 1rem;
  }

  /* Diagrams */
  .block-diagram {
    padding: 0.75rem;
    overflow: hidden;
  }

  .diagram-svg-wrap {
    max-width: 100%;
  }

  .diagram-caption {
    font-size: 0.75rem;
  }

  /* Canvas interactives — proportional scaling */
  .interactive-canvas {
    width: 100% !important;
    height: auto !important;
    max-height: none;
  }

  .interactive-container {
    width: 100%;
  }

  .interactive-slider {
    flex-wrap: wrap;
    justify-content: center;
  }

  .interactive-slider input[type="range"] {
    width: 100px;
    height: 24px; /* easier to grab */
  }

  .interactive-slider input[type="range"]::-webkit-slider-thumb {
    width: 22px;
    height: 22px;
  }

  .interactive-slider input[type="range"]::-moz-range-thumb {
    width: 22px;
    height: 22px;
  }

  .interactive-controls {
    gap: 0.5rem;
    width: 100%;
    justify-content: center;
  }

  .interactive-btn {
    min-height: 36px;
    padding: 0.5rem 1rem;
  }

  .switch-btn {
    min-height: 44px;
    padding: 0.6rem 1.5rem;
  }
}

/* ── Small phones (480px) ── */
@media (max-width: 480px) {
  .landing-title {
    font-size: 2rem;
  }

  #main-nav {
    flex-direction: column;
    gap: 0.35rem;
  }

  .nav-brand {
    font-size: 1rem;
  }

  .nav-links {
    gap: 1.25rem;
  }

  .nav-link {
    font-size: 0.75rem;
    padding: 0.4rem 0.3rem;
  }

  #app-content {
    padding-top: 5rem;
  }

  .screen {
    padding: 1rem 0.75rem 2rem;
    padding-bottom: max(2rem, env(safe-area-inset-bottom));
  }

  .chapter-heading {
    font-size: 1.3rem;
  }

  .chapter-num {
    font-size: 0.75rem;
  }

  .screen-title {
    font-size: 1.5rem;
  }

  .block-scene {
    font-size: 0.95rem;
    padding-left: 1rem;
  }

  .block-explanation {
    font-size: 0.9rem;
  }

  .block-key-concept,
  .block-analogy {
    font-size: 0.9rem;
    padding: 0.9rem 1rem;
  }

  .block-interactive {
    padding: 1rem 0.5rem;
  }

  /* Chapter cards */
  .chapter-card {
    padding: 0.85rem 1rem;
    gap: 0.75rem;
  }

  .chapter-card-num {
    font-size: 1.1rem;
    min-width: 1.75rem;
  }

  .chapter-card-info h3 {
    font-size: 0.9rem;
  }

  .chapter-card-info p {
    font-size: 0.75rem;
  }

  /* Topic picker */
  .topic-card {
    padding: 1rem;
    gap: 0.85rem;
  }

  .topic-icon {
    font-size: 1.75rem;
  }

  .topic-title {
    font-size: 1rem;
  }

  .topic-badge {
    font-size: 0.6rem;
    padding: 0.15rem 0.4rem;
  }

  /* Quiz */
  .quiz-option {
    padding: 0.85rem 0.9rem;
    font-size: 0.9rem;
  }

  .quiz-question {
    font-size: 1rem;
  }

  /* Graph */
  #graph-container {
    height: 350px;
  }

  /* Diagrams — ensure captions readable */
  .diagram-caption {
    font-size: 0.7rem;
    letter-spacing: 0.04em;
  }

  /* Chapter navigation */
  .chapter-navigation {
    gap: 0.5rem;
    margin-top: 2rem;
    padding-top: 1.5rem;
  }

  .chapter-navigation .btn {
    font-size: 0.85rem;
    padding: 0.6rem 0.75rem;
  }

  /* Interactive widgets */
  .amber-piece {
    width: 60px;
    height: 60px;
    font-size: 1.25rem;
  }

  .amber-wool {
    width: 65px;
    height: 65px;
  }

  .compass-dial {
    width: 85px;
    height: 85px;
  }

  .compass-needle {
    width: 60px;
    margin-left: -30px;
  }

  .interactive-slider label {
    min-width: auto;
    font-size: 0.75rem;
  }

  .interactive-slider input[type="range"] {
    width: 80px;
  }

  .slider-value {
    font-size: 0.8rem;
  }
}

/* ── Tiny phones (360px) ── */
@media (max-width: 360px) {
  .landing-title {
    font-size: 1.75rem;
  }

  .landing-subtitle {
    font-size: 0.9rem;
  }

  .screen {
    padding: 0.75rem 0.5rem 2rem;
  }

  .chapter-heading {
    font-size: 1.15rem;
  }

  .nav-links {
    gap: 1rem;
  }

  .topic-card {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .topic-badge {
    position: static;
    align-self: center;
    margin-top: 0.25rem;
  }

  .chapter-card-status {
    display: none;
  }
}

/* === Large screens === */
@media (min-width: 1200px) {
  .chapter-grid {
    grid-template-columns: 1fr 1fr;
  }
}

/* === Landscape phones — shorter viewports === */
@media (max-height: 500px) and (orientation: landscape) {
  #landing-screen {
    min-height: auto;
  }

  .landing-title {
    font-size: 2rem;
  }

  .landing-subtitle {
    margin-bottom: 0.5rem;
  }

  .landing-desc {
    margin-bottom: 1rem;
  }

  #app-content {
    padding-top: 3.5rem;
  }

  .screen {
    padding: 1rem 1rem 2rem;
  }

  #graph-container {
    height: 300px;
  }
}

/* === Touch device hints === */
@media (hover: none) and (pointer: coarse) {
  /* Larger touch targets on touch devices */
  .quiz-option {
    min-height: 48px;
  }

  .chapter-card {
    min-height: 60px;
  }

  .nav-link {
    min-height: 36px;
    display: inline-flex;
    align-items: center;
  }

  /* Remove hover effects that don't apply on touch */
  .chapter-card:hover:not(.locked) {
    transform: none;
  }

  .topic-card:hover {
    transform: none;
  }

  /* Active state instead of hover for touch feedback */
  .quiz-option:active:not(:disabled) {
    background: var(--bg-card);
    border-color: var(--accent-electric);
  }

  .chapter-card:active:not(.locked) {
    border-color: var(--accent-electric);
    background: var(--bg-card);
  }

  .topic-card:active {
    border-color: var(--accent-electric);
    background: var(--bg-card);
  }

  .btn:active:not(:disabled) {
    transform: scale(0.97);
  }
}