/* ========================================
   Responsive CSS - Multi-device adaptation
   Covers: PC (1920+), Tablet (768-1024), Mobile (375-767)
   Loaded AFTER page-specific CSS to fill gaps
   ======================================== */

/* ===== Global Box Model ===== */
*, *::before, *::after {
  box-sizing: border-box;
}

/* ===== Safe Area (Notch / Home Indicator) ===== */
:root {
  --sat: env(safe-area-inset-top, 0px);
  --sab: env(safe-area-inset-bottom, 0px);
  --sal: env(safe-area-inset-left, 0px);
  --sar: env(safe-area-inset-right, 0px);
}

/* ===== Touch Device Optimization ===== */
@media (hover: none) and (pointer: coarse) {
  /* Increase touch targets on touch devices */
  button, a, [role="button"], .clickable,
  .nav-btn, .back-btn, .level-btn, .scene-btn,
  .scene-card, .word-card, .meaning-card {
    min-height: 44px;
    min-width: 44px;
  }

  /* Use :active for touch feedback instead of hover */
  .scene-card:active {
    border-color: #6366f1;
    background: rgba(99, 102, 241, 0.08);
  }

  .nav-btn:active,
  .back-btn:active {
    background: #6366f1;
    color: white;
  }

  /* Prevent iOS zoom on input focus */
  input[type="text"],
  input[type="search"],
  textarea,
  select {
    font-size: 16px !important;
  }
}

/* ===== Tablet Portrait (601px - 1024px) ===== */
@media (min-width: 601px) and (max-width: 1024px) {
  /* Scene select grid */
  .scene-grid {
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 14px;
  }

  /* Word match - adjust layout */
  .game-area {
    gap: 30px;
  }

  .words-column {
    max-width: 320px;
  }

  .meanings-column {
    max-width: 260px;
  }

  /* Home page feature grid */
  .feature-grid,
  .mode-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ===== Mobile (max-width: 600px) ===== */
@media (max-width: 600px) {
  /* ===== Common Mobile ===== */
  html {
    font-size: 15px;
  }

  body {
    -webkit-text-size-adjust: 100%;
    -webkit-tap-highlight-color: transparent;
    overflow-x: hidden;
  }

  /* ===== Header / Nav ===== */
  .nav-header,
  .header {
    padding: 12px 16px;
    padding-top: calc(12px + var(--sat));
  }

  .nav-header .nav-title,
  .header-title {
    font-size: 15px;
  }

  /* ===== Home Page ===== */
  .hero-title {
    font-size: 32px;
  }

  .hero-subtitle {
    font-size: 15px;
  }

  .feature-grid,
  .mode-grid {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .feature-card,
  .mode-card {
    padding: 20px;
  }

  /* ===== Scene Select ===== */
  .level-filter {
    padding: 12px 16px;
    gap: 6px;
  }

  .level-btn {
    padding: 8px 14px;
    font-size: 13px;
  }

  .scene-list {
    padding: 16px;
  }

  .scene-grid {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .scene-card {
    padding: 14px;
  }

  .scene-name {
    font-size: 14px;
  }

  .scene-btn {
    padding: 10px 12px;
    font-size: 13px;
  }

  .search-box {
    padding: 12px 16px;
  }

  .search-input {
    font-size: 16px;
    padding: 12px 16px 12px 44px;
  }

  /* ===== Chat / Practice Pages ===== */
  .main-content {
    padding: 70px 16px 160px;
  }

  .chat-area {
    padding: 16px;
    gap: 12px;
  }

  .message {
    max-width: 92%;
    gap: 8px;
  }

  .avatar {
    width: 32px;
    height: 32px;
    font-size: 16px;
  }

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

  .bottom-controls {
    padding: 12px 16px calc(16px + var(--sab));
  }

  .hold-btn {
    width: 64px;
    height: 64px;
    font-size: 24px;
  }

  .control-hint {
    font-size: 12px;
  }

  /* ===== Word Match Mobile ===== */
  .game-container {
    padding: 12px;
  }

  /* ===== AI Chat Page ===== */
  .chat-messages {
    padding: 16px;
  }

  .message-bubble {
    max-width: 90%;
    padding: 12px 16px;
  }

  .input-area {
    padding: 12px 16px calc(12px + var(--sab));
  }

  /* ===== Voice Call Page ===== */
  .call-controls {
    padding-bottom: calc(20px + var(--sab));
  }

  /* ===== Modal ===== */
  .modal {
    padding: 32px 24px;
    width: 92%;
    max-width: none;
    border-radius: 20px;
  }

  .modal-title {
    font-size: 22px;
  }

  .modal-icon {
    font-size: 56px;
  }
}

/* ===== Small Mobile (max-width: 380px) ===== */
@media (max-width: 380px) {
  .hero-title {
    font-size: 26px;
  }

  .words-column {
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
  }

  .word-card {
    padding: 10px 8px;
    min-height: 60px;
  }

  .hold-btn {
    width: 56px;
    height: 56px;
    font-size: 22px;
  }
}

/* ===== Landscape Mobile ===== */
@media (max-height: 500px) and (orientation: landscape) {
  .main-content {
    padding-top: 60px;
    padding-bottom: 120px;
  }

  .bottom-controls {
    padding: 8px 16px calc(8px + var(--sab));
  }

  .hold-btn {
    width: 52px;
    height: 52px;
    font-size: 20px;
  }

  .control-hint {
    display: none;
  }

  .chat-area {
    padding: 8px 16px;
  }

  .nav-header,
  .header {
    padding: 8px 16px;
    min-height: 48px;
  }
}

/* ===== Large PC (min-width: 1400px) ===== */
@media (min-width: 1400px) {
  .main-content,
  .game-container {
    max-width: 1000px;
  }

  .scene-list {
    max-width: 1100px;
  }

  .scene-grid {
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  }
}

/* ===== Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms;
    animation-iteration-count: 1;
    transition-duration: 0.01ms;
  }
}

/* ===== High Contrast ===== */
@media (prefers-contrast: high) {
  .bubble, .scene-card, .word-card, .meaning-card {
    border-width: 2px;
  }
}