/* ==========================================================================
   videos.css - Giao diện Video Giải trí & Học ngoại ngữ PolyLingo
   Tông màu: Đỏ son (#B3261E), Vàng hoàng gia (#C9A227), Trắng kem (#FAF7F2)
   Tối ưu hóa: 1440px, 1024px, 768px, 375px (Mobile-first layout)
   ========================================================================== */

:root {
  --video-accent: #B3261E;
  --video-accent-dark: #8A1C16;
  --video-accent-light: #FFEDED;
  --video-gold: #C9A227;
  --video-gold-light: #FFF9E6;
  --video-gold-dark: #9A7B1C;
  --video-bg-card: #FFFFFF;
  --video-bg-alt: #F9F7F5;
  --video-text-main: #1F2937;
  --video-text-sub: #4B5563;
  --video-text-muted: #9CA3AF;
  --video-border: #E5E7EB;
  --video-border-subtle: #F3F4F6;
  --video-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --video-shadow-md: 0 4px 12px rgba(179, 38, 30, 0.08);
  --video-shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
  --video-radius: 14px;
}

/* 1. KHUNG CHÍNH (CONTAINER) */
.video-module-root {
  max-width: 1360px;
  margin: 0 auto;
  padding: 1.5rem 1rem 4rem;
  font-family: inherit;
  color: var(--video-text-main);
}

/* 2. THANH TIÊU ĐỀ & ĐIỀU HƯỚNG TRÊN */
.video-top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1.75rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--video-border);
}

.video-heading-wrap h1 {
  font-family: 'Noto Serif SC', 'Playfair Display', serif;
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--video-accent);
  margin: 0 0 0.35rem 0;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.video-heading-badge {
  font-family: inherit;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  background: var(--video-gold-light);
  color: var(--video-gold-dark);
  border: 1px solid rgba(201, 162, 39, 0.3);
}

.video-sub-desc {
  font-size: 0.925rem;
  color: var(--video-text-sub);
  margin: 0;
}

.video-top-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.video-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.55rem 1.1rem;
  border-radius: 10px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  text-decoration: none;
}

.video-btn-primary {
  background: linear-gradient(135deg, var(--video-accent), var(--video-accent-dark));
  color: #FFFFFF;
  box-shadow: 0 2px 6px rgba(179, 38, 30, 0.3);
}

.video-btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 10px rgba(179, 38, 30, 0.4);
}

.video-btn-outline {
  background: #FFFFFF;
  color: var(--video-accent);
  border-color: rgba(179, 38, 30, 0.35);
}

.video-btn-outline:hover {
  background: var(--video-accent-light);
  border-color: var(--video-accent);
}

.video-btn-secondary {
  background: var(--video-bg-alt);
  color: var(--video-text-main);
  border-color: var(--video-border);
}

.video-btn-secondary:hover {
  background: #EAE6DF;
}

/* 3. THANH TÌM KIẾM & BỘ LỌC */
.video-filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  align-items: center;
  margin-bottom: 2rem;
  background: var(--video-bg-card);
  padding: 1rem 1.25rem;
  border-radius: var(--video-radius);
  border: 1px solid var(--video-border);
  box-shadow: var(--video-shadow-sm);
}

.video-search-box {
  flex: 1 1 240px;
  position: relative;
}

.video-search-input {
  width: 100%;
  padding: 0.6rem 1rem 0.6rem 2.35rem;
  border-radius: 8px;
  border: 1px solid var(--video-border);
  font-size: 0.925rem;
  outline: none;
  background: var(--video-bg-alt);
  transition: border-color 0.2s, box-shadow 0.2s;
}

.video-search-input:focus {
  border-color: var(--video-accent);
  background: #FFFFFF;
  box-shadow: 0 0 0 3px rgba(179, 38, 30, 0.12);
}

.video-search-icon {
  position: absolute;
  left: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--video-text-muted);
  pointer-events: none;
}

.video-select-filter {
  padding: 0.6rem 1rem;
  border-radius: 8px;
  border: 1px solid var(--video-border);
  background: var(--video-bg-alt);
  font-size: 0.9rem;
  color: var(--video-text-main);
  outline: none;
  cursor: pointer;
}

.video-select-filter:focus {
  border-color: var(--video-accent);
}

/* 4. LƯỚI THẺ VIDEO (GRID) */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
  gap: 1.5rem;
}

.video-card {
  background: var(--video-bg-card);
  border-radius: var(--video-radius);
  border: 1px solid var(--video-border);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
  cursor: pointer;
  position: relative;
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--video-shadow-md);
  border-color: rgba(179, 38, 30, 0.4);
}

/* Thumbnail 16:9 */
.video-thumb-wrap {
  position: relative;
  width: 100%;
  padding-top: 56.25%; /* 16:9 ratio */
  background: #1A1A1A;
  overflow: hidden;
}

.video-thumb-img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.video-card:hover .video-thumb-img {
  transform: scale(1.04);
}

.video-thumb-placeholder {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, #2D1515 0%, #171111 100%);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--video-gold);
  gap: 0.5rem;
}

.video-thumb-play-overlay {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: rgba(179, 38, 30, 0.9);
  color: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.4);
  transition: transform 0.2s ease, background 0.2s ease;
}

.video-card:hover .video-thumb-play-overlay {
  transform: translate(-50%, -50%) scale(1.12);
  background: var(--video-accent);
}

.video-badge-duration {
  position: absolute;
  right: 0.6rem;
  bottom: 0.6rem;
  background: rgba(0, 0, 0, 0.78);
  color: #FFFFFF;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
}

.video-badge-status {
  position: absolute;
  left: 0.6rem;
  top: 0.6rem;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.2rem 0.55rem;
  border-radius: 6px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.25);
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.video-badge-watched {
  background: #10B981;
  color: #FFFFFF;
}

.video-badge-progress {
  background: var(--video-gold);
  color: #382400;
}

.video-badge-local {
  position: absolute;
  right: 0.6rem;
  top: 0.6rem;
  background: #4F46E5;
  color: #FFFFFF;
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.2rem 0.5rem;
  border-radius: 6px;
}

.video-card-body {
  padding: 1rem 1.15rem;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.video-card-tags {
  display: flex;
  gap: 0.45rem;
  margin-bottom: 0.6rem;
}

.video-tag {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.15rem 0.5rem;
  border-radius: 6px;
  background: var(--video-accent-light);
  color: var(--video-accent);
}

.video-tag-topic {
  background: var(--video-bg-alt);
  color: var(--video-text-sub);
}

.video-card-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--video-text-main);
  line-height: 1.4;
  margin: 0 0 0.5rem 0;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.video-card-desc {
  font-size: 0.85rem;
  color: var(--video-text-sub);
  line-height: 1.45;
  margin: 0 0 1rem 0;
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.video-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--video-border-subtle);
  padding-top: 0.75rem;
  font-size: 0.825rem;
}

.video-card-progress-bar {
  height: 4px;
  background: var(--video-border);
  border-radius: 2px;
  overflow: hidden;
  width: 100%;
  margin-bottom: 0.6rem;
}

.video-card-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--video-gold), var(--video-accent));
  transition: width 0.3s ease;
}

/* 5. TRẠNG THÁI RỖNG (EMPTY STATE) */
.video-empty-state {
  text-align: center;
  padding: 3.5rem 1.5rem;
  background: var(--video-bg-card);
  border-radius: var(--video-radius);
  border: 1px dashed var(--video-border);
  max-width: 540px;
  margin: 2rem auto;
}

.video-empty-icon {
  font-size: 3.5rem;
  margin-bottom: 1rem;
}

.video-empty-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--video-text-main);
  margin-bottom: 0.5rem;
}

.video-empty-desc {
  font-size: 0.925rem;
  color: var(--video-text-sub);
  margin-bottom: 1.5rem;
  line-height: 1.5;
}

.video-empty-actions {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* 6. GIAO DIỆN TRANG XEM VIDEO (WATCH PAGE) */
.video-watch-container {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.video-watch-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
  background: var(--video-bg-card);
  padding: 0.75rem 1.25rem;
  border-radius: var(--video-radius);
  border: 1px solid var(--video-border);
}

.video-back-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--video-accent);
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  background: none;
  border: none;
  padding: 0.3rem 0.6rem;
  border-radius: 6px;
  transition: background 0.15s;
}

.video-back-btn:hover {
  background: var(--video-accent-light);
}

.video-watch-title-area {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.video-watch-main-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin: 0;
  color: var(--video-text-main);
}

/* Bố cục 2 cột cho trang xem (Desktop) */
.video-watch-grid {
  display: grid;
  grid-template-columns: 1.7fr 1.1fr;
  gap: 1.5rem;
  align-items: start;
}

/* Cột bên trái: Player, Phụ đề, Controls, Shadowing */
.video-player-column {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* Khung video YouTube / Giả lập */
.video-player-frame-wrap {
  position: relative;
  width: 100%;
  padding-top: 56.25%; /* 16:9 */
  background: #0D0D0D;
  border-radius: var(--video-radius);
  overflow: hidden;
  box-shadow: var(--video-shadow-md);
}

.video-iframe-el,
.video-sample-player-el {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: none;
}

/* Khung video mẫu khi chưa có link YouTube */
.video-sample-player-el {
  background: radial-gradient(circle at center, #261717 0%, #0F0A0A 100%);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: #FFFFFF;
  padding: 1.5rem;
  text-align: center;
}

.video-sample-badge {
  background: var(--video-gold);
  color: #2D1A00;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  margin-bottom: 0.8rem;
}

.video-sample-time-display {
  font-size: 2.2rem;
  font-family: monospace;
  font-weight: 700;
  color: var(--video-gold-light);
  margin-bottom: 0.5rem;
  letter-spacing: 2px;
}

.video-sample-tip {
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.75);
  max-width: 400px;
  line-height: 1.4;
}

/* Thông báo file:// hoặc lỗi YouTube */
.video-fallback-banner {
  background: #FFFBEB;
  border: 1px solid #FCD34D;
  color: #92400E;
  padding: 0.75rem 1rem;
  border-radius: 10px;
  font-size: 0.875rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

/* 7. KHUNG PHỤ ĐỀ LỚN & ĐA CHẾ ĐỘ */
.video-sub-box {
  background: var(--video-bg-card);
  border-radius: var(--video-radius);
  border: 1px solid var(--video-border);
  padding: 1.25rem 1.5rem;
  box-shadow: var(--video-shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  position: relative;
  min-height: 140px;
  justify-content: center;
}

.video-sub-mode-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--video-border-subtle);
  font-size: 0.825rem;
  color: var(--video-text-sub);
}

.video-sub-mode-select {
  padding: 0.3rem 0.6rem;
  border-radius: 6px;
  border: 1px solid var(--video-border);
  font-size: 0.825rem;
  background: var(--video-bg-alt);
  color: var(--video-text-main);
  outline: none;
  cursor: pointer;
}

.video-sub-content {
  text-align: center;
  padding: 0.5rem 0;
}

.video-sub-zh {
  font-family: 'Noto Serif SC', 'PingFang SC', sans-serif;
  font-size: 1.85rem;
  font-weight: 700;
  color: #111827;
  line-height: 1.45;
  margin-bottom: 0.35rem;
}

.video-sub-word {
  display: inline-block;
  padding: 0 0.15rem;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.15s ease;
  position: relative;
}

.video-sub-word:hover {
  background: var(--video-gold-light);
  color: var(--video-accent-dark);
  box-shadow: 0 0 0 2px var(--video-gold);
}

.video-sub-py {
  font-size: 1.05rem;
  color: var(--video-accent);
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.video-sub-vi {
  font-size: 1rem;
  color: #374151;
  font-weight: 500;
}

.video-sub-hidden-notice {
  color: var(--video-text-muted);
  font-style: italic;
  font-size: 0.95rem;
}

/* 8. THANH ĐIỀU KHIỂN HỌC TẬP (LEARNING CONTROLS) */
.video-controls-bar {
  background: var(--video-bg-card);
  border-radius: var(--video-radius);
  border: 1px solid var(--video-border);
  padding: 0.85rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.video-ctrl-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.video-ctrl-btn {
  background: var(--video-bg-alt);
  border: 1px solid var(--video-border);
  color: var(--video-text-main);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.45rem 0.85rem;
  border-radius: 8px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: all 0.15s ease;
}

.video-ctrl-btn:hover {
  background: #EAE6DF;
  border-color: #D1D5DB;
}

.video-ctrl-btn.active {
  background: var(--video-accent);
  color: #FFFFFF;
  border-color: var(--video-accent);
}

.video-ctrl-play-btn {
  background: var(--video-accent);
  color: #FFFFFF;
  border-color: var(--video-accent);
  padding: 0.5rem 1.2rem;
  font-size: 0.95rem;
}

.video-ctrl-play-btn:hover {
  background: var(--video-accent-dark);
}

.video-time-indicator {
  font-size: 0.85rem;
  font-family: monospace;
  font-weight: 600;
  color: var(--video-text-sub);
  padding: 0 0.4rem;
}

.video-speed-selector {
  display: flex;
  background: var(--video-bg-alt);
  border-radius: 8px;
  border: 1px solid var(--video-border);
  overflow: hidden;
}

.video-speed-btn {
  background: none;
  border: none;
  padding: 0.35rem 0.65rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--video-text-sub);
  cursor: pointer;
  transition: all 0.15s;
}

.video-speed-btn.active {
  background: var(--video-accent);
  color: #FFFFFF;
}

/* 9. CHẾ ĐỘ NÓI THEO (SHADOWING PANEL) */
.video-shadow-panel {
  background: linear-gradient(135deg, #FFFDF8 0%, #FFF5F5 100%);
  border: 2px solid var(--video-gold);
  border-radius: var(--video-radius);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  box-shadow: 0 4px 14px rgba(201, 162, 39, 0.15);
}

.video-shadow-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.video-shadow-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--video-accent-dark);
  display: flex;
  align-items: center;
  gap: 0.45rem;
  margin: 0;
}

.video-shadow-body {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.85rem;
  text-align: center;
}

.video-shadow-target-zh {
  font-size: 1.5rem;
  font-weight: 700;
  color: #1F2937;
  font-family: 'Noto Serif SC', serif;
}

.video-shadow-mic-btn {
  width: 68px;
  height: 68px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--video-accent), var(--video-accent-dark));
  color: #FFFFFF;
  border: none;
  font-size: 1.75rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 15px rgba(179, 38, 30, 0.35);
  transition: transform 0.2s, box-shadow 0.2s;
}

.video-shadow-mic-btn:hover {
  transform: scale(1.06);
}

.video-shadow-mic-btn.listening {
  animation: pulse-ring 1.3s cubic-bezier(0.24, 0, 0.38, 1) infinite;
  background: #DC2626;
}

@keyframes pulse-ring {
  0% { box-shadow: 0 0 0 0 rgba(220, 38, 38, 0.6); }
  70% { box-shadow: 0 0 0 16px rgba(220, 38, 38, 0); }
  100% { box-shadow: 0 0 0 0 rgba(220, 38, 38, 0); }
}

.video-shadow-result-wrap {
  width: 100%;
  background: #FFFFFF;
  border: 1px solid var(--video-border);
  border-radius: 10px;
  padding: 0.85rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.video-shadow-chars-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.3rem;
  font-size: 1.25rem;
  font-weight: 700;
}

.video-char-ok {
  color: #059669;
  background: #D1FAE5;
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
}

.video-char-bad {
  color: #DC2626;
  background: #FEE2E2;
  text-decoration: line-through;
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
}

.video-shadow-score-badge {
  font-size: 0.95rem;
  font-weight: 700;
  display: inline-block;
  padding: 0.25rem 0.85rem;
  border-radius: 999px;
  margin: 0 auto;
}

.video-shadow-pass {
  background: #D1FAE5;
  color: #065F46;
}

.video-shadow-fail {
  background: #FEF3C7;
  color: #92400E;
}

/* 10. CỘT BẢNG LỜI THOẠI (TRANSCRIPT COLUMN) */
.video-transcript-column {
  background: var(--video-bg-card);
  border-radius: var(--video-radius);
  border: 1px solid var(--video-border);
  box-shadow: var(--video-shadow-sm);
  display: flex;
  flex-direction: column;
  max-height: 720px;
  overflow: hidden;
}

.video-transcript-header {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--video-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #FAFAF9;
}

.video-transcript-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--video-text-main);
  margin: 0;
  display: flex;
  align-items: center;
  gap: 0.45rem;
}

.video-transcript-list {
  overflow-y: auto;
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  flex: 1;
}

.video-transcript-item {
  padding: 0.75rem 0.85rem;
  border-radius: 10px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.18s ease;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  background: var(--video-bg-alt);
}

.video-transcript-item:hover {
  background: #F0ECE4;
  border-color: #D6D1C7;
}

.video-transcript-item.active {
  background: var(--video-gold-light);
  border-color: var(--video-gold);
  box-shadow: 0 2px 6px rgba(201, 162, 39, 0.2);
}

.video-transcript-item-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.75rem;
  color: var(--video-text-muted);
}

.video-transcript-time {
  font-family: monospace;
  font-weight: 600;
  color: var(--video-accent);
}

.video-transcript-zh {
  font-family: 'Noto Serif SC', serif;
  font-size: 1.05rem;
  font-weight: 700;
  color: #111827;
  line-height: 1.4;
}

.video-transcript-py {
  font-size: 0.825rem;
  color: var(--video-accent);
  font-weight: 500;
}

.video-transcript-vi {
  font-size: 0.825rem;
  color: #4B5563;
}

/* 11. BÀI KIỂM TRA CUỐI VIDEO (END QUIZ) */
.video-quiz-panel {
  background: var(--video-bg-card);
  border-radius: var(--video-radius);
  border: 2px solid var(--video-accent);
  padding: 1.5rem;
  box-shadow: var(--video-shadow-md);
  margin-top: 1rem;
}

.video-quiz-header {
  text-align: center;
  margin-bottom: 1.25rem;
}

.video-quiz-header h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--video-accent);
  margin: 0 0 0.35rem 0;
}

.video-quiz-card {
  background: var(--video-bg-alt);
  border: 1px solid var(--video-border);
  border-radius: 12px;
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.video-quiz-q-num {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--video-accent);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 0.4rem;
}

.video-quiz-question {
  font-size: 1.05rem;
  font-weight: 700;
  color: #1F2937;
  margin-bottom: 1rem;
}

.video-quiz-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.6rem;
}

.video-quiz-opt-btn {
  background: #FFFFFF;
  border: 1px solid var(--video-border);
  border-radius: 8px;
  padding: 0.7rem 0.9rem;
  text-align: left;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
}

.video-quiz-opt-btn:hover:not(:disabled) {
  background: var(--video-accent-light);
  border-color: var(--video-accent);
}

.video-quiz-opt-btn.correct {
  background: #D1FAE5 !important;
  border-color: #10B981 !important;
  color: #065F46 !important;
}

.video-quiz-opt-btn.wrong {
  background: #FEE2E2 !important;
  border-color: #EF4444 !important;
  color: #991B1B !important;
}

.video-quiz-summary {
  text-align: center;
  padding: 1rem;
  background: var(--video-gold-light);
  border-radius: 10px;
  margin-top: 1rem;
}

/* 12. POPUP TRA TỪ TỨC THÌ (WORD LOOKUP MODAL) */
.video-lookup-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  backdrop-filter: blur(2px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.video-lookup-card {
  background: #FFFFFF;
  border-radius: 16px;
  box-shadow: var(--video-shadow-lg);
  max-width: 420px;
  width: 100%;
  padding: 1.5rem;
  position: relative;
  border: 1px solid var(--video-border);
  animation: zoomIn 0.2s ease-out;
}

@keyframes zoomIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

.video-lookup-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: none;
  border: none;
  font-size: 1.25rem;
  cursor: pointer;
  color: var(--video-text-muted);
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.video-lookup-close:hover {
  background: var(--video-bg-alt);
  color: var(--video-text-main);
}

.video-lookup-head {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.video-lookup-hanzi {
  font-family: 'Noto Serif SC', serif;
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--video-accent);
  line-height: 1;
}

.video-lookup-py {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--video-gold-dark);
}

.video-lookup-audio-btn {
  background: var(--video-accent-light);
  border: none;
  color: var(--video-accent);
  width: 32px;
  height: 32px;
  border-radius: 50%;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.95rem;
  transition: transform 0.15s;
}

.video-lookup-audio-btn:hover {
  transform: scale(1.1);
}

.video-lookup-mean-box {
  background: var(--video-bg-alt);
  border-radius: 8px;
  padding: 0.85rem;
  margin-bottom: 1rem;
  font-size: 0.95rem;
  line-height: 1.5;
  color: #1F2937;
}

.video-lookup-mean-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--video-text-muted);
  margin-bottom: 0.25rem;
}

.video-lookup-actions {
  display: flex;
  gap: 0.6rem;
}

/* 13. MODAL THÊM VIDEO & HƯỚNG DẪN */
.video-modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(3px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.video-modal-box {
  background: #FFFFFF;
  border-radius: 16px;
  box-shadow: var(--video-shadow-lg);
  max-width: 600px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  padding: 1.75rem;
  position: relative;
  border: 1px solid var(--video-border);
}

.video-modal-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--video-accent);
  margin: 0 0 1.25rem 0;
}

.video-form-group {
  margin-bottom: 1rem;
}

.video-form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
  color: var(--video-text-main);
}

.video-form-input,
.video-form-select,
.video-form-textarea {
  width: 100%;
  padding: 0.65rem 0.85rem;
  border-radius: 8px;
  border: 1px solid var(--video-border);
  font-size: 0.9rem;
  background: var(--video-bg-alt);
  outline: none;
  font-family: inherit;
}

.video-form-input:focus,
.video-form-select:focus,
.video-form-textarea:focus {
  border-color: var(--video-accent);
  background: #FFFFFF;
}

.video-code-export-box {
  background: #1E1E1E;
  color: #D4D4D4;
  font-family: Consolas, monospace;
  font-size: 0.825rem;
  padding: 1rem;
  border-radius: 8px;
  overflow-x: auto;
  max-height: 220px;
  white-space: pre;
}

/* 14. PHÍM TẮT TIỆN ÍCH */
.video-shortcuts-guide {
  font-size: 0.78rem;
  color: var(--video-text-muted);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.video-kbd {
  background: #F3F4F6;
  border: 1px solid #D1D5DB;
  border-radius: 4px;
  padding: 0.1rem 0.35rem;
  font-family: monospace;
  font-size: 0.72rem;
  color: #374151;
  box-shadow: 0 1px 1px rgba(0,0,0,0.1);
}

/* 15. RESPONSIVE BREAKPOINTS (1024px & 375px) */
@media (max-width: 1024px) {
  .video-watch-grid {
    grid-template-columns: 1fr;
  }
  .video-transcript-column {
    max-height: 480px;
  }
}

@media (max-width: 640px) {
  .video-module-root {
    padding: 1rem 0.6rem 3rem;
  }
  .video-heading-wrap h1 {
    font-size: 1.4rem;
  }
  .video-sub-zh {
    font-size: 1.4rem;
  }
  .video-sub-py {
    font-size: 0.95rem;
  }
  .video-sub-vi {
    font-size: 0.9rem;
  }
  .video-quiz-options {
    grid-template-columns: 1fr;
  }
  .video-controls-bar {
    justify-content: center;
  }
}