/* ==========================================================================
   TOEIC MASTER RESPONSIVE — responsive.css
   Mobile-First Optimization, Touch Drawer, Breakpoints
   ========================================================================== */

/* Mobile Bottom Navigation Bar for Exam */
.mobile-exam-bottom-bar {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 90;
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 1px solid var(--border-glass);
  padding: 10px 16px;
  padding-bottom: max(10px, env(safe-area-inset-bottom, 10px));
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.4);
  gap: 8px;
  flex-wrap: nowrap;
}

/* Mobile Drawer (Bottom Sheet) */
.mobile-palette-drawer {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 200;
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
}

.mobile-palette-drawer.open {
  opacity: 1;
  pointer-events: auto;
}

.drawer-content {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  max-height: 85vh;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-glass);
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  padding: 20px 18px;
  padding-bottom: max(20px, env(safe-area-inset-bottom, 20px));
  display: flex;
  flex-direction: column;
  transform: translateY(100%);
  transition: transform var(--transition-normal);
  box-shadow: var(--shadow-lg);
}

.mobile-palette-drawer.open .drawer-content {
  transform: translateY(0);
}

.drawer-drag-handle {
  width: 44px;
  height: 5px;
  background: var(--border-subtle);
  border-radius: var(--radius-full);
  margin: -8px auto 14px;
}

.drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

/* Eliminate nested scroll traps in mobile palette drawer */
.drawer-palette-scroll {
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
  max-height: calc(85vh - 160px);
  padding-right: 2px;
}

.mobile-palette-drawer .palette-grid {
  max-height: none !important;
  overflow-y: visible !important;
}

/* ── Responsive Breakpoints ── */
@media (max-width: 1024px) {
  .exam-layout {
    grid-template-columns: 1fr;
    gap: 20px;
    padding-bottom: 100px;
  }

  .exam-sidebar-col {
    display: none; /* Hidden on tablet/mobile, opened via drawer */
  }

  /* Unify: Hide duplicate timer and submit from top navbar on mobile/tablet */
  .exam-navbar #desktop-timer-wrap,
  .exam-navbar .nav-links {
    display: none !important;
  }

  .mobile-exam-bottom-bar {
    display: flex;
  }

  .mobile-palette-drawer {
    display: block;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 12px;
  }

  .app-navbar {
    padding: 10px 14px;
  }

  .exam-navbar {
    padding: 8px 12px;
    gap: 8px;
    display: flex;
    align-items: center;
    justify-content: space-between;
  }
  
  .exam-navbar .nav-brand {
    width: auto;
    display: flex;
    align-items: center;
    gap: 6px;
    flex-shrink: 0;
  }

  .exam-exit-link {
    padding: 5px 8px;
    font-size: 0.82rem;
  }

  .exam-navbar .brand-badge {
    padding: 3px 8px;
    font-size: 0.78rem;
  }

  .header-audio-player {
    flex: 1;
    min-width: 0;
    max-width: none;
    margin: 0;
    padding: 3px 8px;
    gap: 8px;
  }

  .header-audio-player .master-lc-play-btn {
    width: 28px;
    height: 28px;
    min-width: 28px;
    font-size: 0.76rem;
  }

  .header-audio-player .master-lc-times {
    font-size: 0.68rem;
  }

  @media (max-width: 380px) {
    .exam-exit-link .exit-label {
      display: none;
    }
  }

  .mobile-exam-bottom-bar {
    padding: 10px 14px;
    gap: 8px;
  }

  .mobile-exam-bottom-bar .exam-timer {
    background: rgba(6, 182, 212, 0.08);
    border: 1px solid rgba(6, 182, 212, 0.3);
    padding: 6px 10px;
    border-radius: var(--radius-full);
    font-size: 1rem;
    font-weight: 800;
    color: var(--cyan);
    display: flex;
    align-items: center;
    gap: 4px;
    letter-spacing: 0.5px;
  }

  .mobile-exam-bottom-bar .btn-secondary {
    padding: 7px 12px;
    font-size: 0.82rem;
    border-radius: var(--radius-full);
  }

  .mobile-exam-bottom-bar .btn-danger {
    padding: 7px 14px;
    font-size: 0.85rem;
    border-radius: var(--radius-full);
  }

  .nav-brand {
    font-size: 1.05rem;
    gap: 6px;
  }

  .brand-badge {
    padding: 2px 6px;
    font-size: 0.72rem;
  }

  .nav-link-btn {
    padding: 6px 10px;
    font-size: 0.82rem;
  }

  .hero-section {
    padding: 32px 0 24px;
  }

  .hero-title {
    font-size: 1.85rem;
    line-height: 1.25;
    margin-bottom: 12px;
  }

  .hero-subtitle {
    font-size: 0.92rem;
    line-height: 1.5;
    margin-bottom: 24px;
  }

  .mode-tabs {
    flex-direction: column;
    width: 100%;
    border-radius: var(--radius-lg);
    padding: 4px;
    margin-bottom: 24px;
  }

  .mode-tab-btn {
    padding: 10px 14px;
    font-size: 0.88rem;
    text-align: center;
    width: 100%;
  }

  .tests-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .test-card {
    padding: 18px 16px;
  }

  .test-title {
    font-size: 1.15rem;
  }

  /* Requirement 1: Make images full-width on mobile */
  .question-item .q-image-container,
  .passages-card .q-image-container,
  .group-review-card .q-image-container,
  .interactive-passage-container {
    margin-left: -12px;
    margin-right: -12px;
    width: calc(100% + 24px);
    max-width: none;
    border-radius: 4px;
    border-left: none;
    border-right: none;
  }

  .q-image-container img,
  .interactive-passage-img {
    width: 100% !important;
    max-width: 100% !important;
    max-height: none !important;
    height: auto !important;
    object-fit: contain !important;
  }

  /* Requirement 3: Compact question cards and smaller font size */
  .question-item {
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    margin-bottom: 10px;
  }

  .passages-card, .group-review-card {
    padding: 10px 12px;
    margin-bottom: 12px;
  }

  .question-header {
    margin-bottom: 4px;
  }

  .q-number-badge {
    font-size: 0.84rem;
  }

  .question-text {
    font-size: 0.88rem;
    line-height: 1.45;
    margin-bottom: 6px;
  }

  .options-group {
    gap: 6px;
  }

  .option-btn {
    padding: 7px 10px;
    font-size: 0.86rem;
    min-height: 40px;
    gap: 8px;
  }

  .option-letter {
    width: 24px;
    height: 24px;
    font-size: 0.78rem;
  }

  .audio-player-box {
    padding: 5px 10px;
    margin-bottom: 6px;
  }

  .audio-play-btn {
    width: 30px;
    height: 30px;
    font-size: 0.85rem;
  }

  .palette-grid {
    grid-template-columns: repeat(6, 1fr);
    gap: 6px;
  }

  .palette-btn {
    height: 38px;
    font-size: 0.82rem;
  }

  .score-val {
    font-size: 2.2rem;
  }

  .score-circle-wrap {
    width: 130px;
    height: 130px;
    margin-bottom: 16px;
  }

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

  .explanation-toggle-btn {
    font-size: 0.78rem;
    padding: 4px 8px;
  }

  .explanation-panel {
    padding: 8px 10px;
    font-size: 0.82rem;
  }

  .translation-box {
    font-size: 0.84rem;
    padding: 6px 8px;
  }

  .interactive-passage-container {
    padding: 8px 10px;
  }

  .passage-click-hint {
    font-size: 0.78rem;
    padding: 5px 8px;
  }

  .group-subquestion-item {
    padding: 8px 10px;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 1.65rem;
  }

  /* Compact Navbar */
  .app-navbar {
    padding: 8px 12px;
  }

  .nav-brand {
    font-size: 0.98rem;
    gap: 6px;
  }

  .nav-links {
    gap: 6px;
  }

  .nav-link-btn {
    padding: 5px 8px;
    font-size: 0.8rem;
  }

  .theme-toggle-btn {
    width: 32px;
    height: 32px;
    font-size: 0.95rem;
  }

  .palette-grid {
    grid-template-columns: repeat(5, 1fr);
    gap: 6px;
  }

  .palette-btn {
    height: 38px;
    font-size: 0.82rem;
  }

  .mobile-exam-bottom-bar {
    padding: 8px 12px;
    padding-bottom: max(8px, env(safe-area-inset-bottom, 8px));
  }

  .exam-timer {
    font-size: 1rem;
  }

  .sentence-text-en {
    font-size: 0.92rem;
  }

  .sentence-text-vi {
    font-size: 0.88rem;
    padding: 6px 10px;
  }

  .sentence-lookup-card {
    padding: 12px 14px;
    margin-top: 10px;
  }

  .sentence-close-btn {
    padding: 2px 8px;
    font-size: 1.4rem;
  }

  /* Interactive Sentence Coordinates on Mobile */
  .sentence-overlay-box {
    border: 1px dashed rgba(99, 102, 241, 0.18);
    background: transparent;
  }

  .sentence-overlay-box.active {
    background: rgba(99, 102, 241, 0.06);
    border: 1.5px dashed var(--accent-primary);
    box-shadow: 0 0 4px rgba(99, 102, 241, 0.25);
  }

  /* Action buttons on Result page */
  .result-hero .result-action-btns .btn {
    width: 100%;
    white-space: normal;
    text-align: center;
    padding: 12px 14px;
    font-size: 0.92rem;
  }
}

/* Mobile Optimization for Review Mode (Result Page) */
@media (max-width: 768px) {
  .review-q-card {
    padding: 10px 10px;
    margin-bottom: 10px;
  }

  .group-review-card {
    padding: 10px 8px;
    margin-bottom: 10px;
  }

  .group-subquestion-item {
    padding: 6px 8px;
  }

  .review-opt-card {
    padding: 5px 8px;
    gap: 7px;
  }

  .review-opt-card .review-opt-letter {
    width: 19px;
    height: 19px;
    min-width: 19px;
    font-size: 0.70rem;
    margin-top: 1px;
  }

  .review-opt-en {
    font-size: 0.88rem;
    line-height: 1.35;
  }

  .review-opt-vi {
    font-size: 0.78rem;
    line-height: 1.35;
  }

  .opt-mark-icon {
    width: 15px;
    height: 15px;
    min-width: 15px;
    font-size: 0.80rem;
    margin-top: 1px;
  }
}

/* Super narrow mobile (e.g. 320px - 380px: iPhone SE, Galaxy Fold front screen) */
@media (max-width: 380px) {
  .exam-exit-link .exit-label {
    display: none;
  }

  .brand-badge {
    display: none;
  }

  .mobile-palette-btn-text {
    display: none;
  }

  .mobile-exam-bottom-bar {
    padding: 8px 8px;
    padding-bottom: max(8px, env(safe-area-inset-bottom, 8px));
    gap: 5px;
  }

  .mobile-exam-bottom-bar .mobile-timer-pill {
    padding: 4px 6px;
    font-size: 0.88rem;
    gap: 2px;
  }

  .mobile-exam-bottom-bar .mobile-palette-trigger {
    padding: 5px 8px;
    font-size: 0.78rem;
  }

  .mobile-exam-bottom-bar .mobile-submit-trigger {
    padding: 5px 8px;
    font-size: 0.8rem;
  }

  .palette-grid {
    grid-template-columns: repeat(4, 1fr);
    gap: 5px;
  }
}