/* ============================================
   学漫剧 - 共享样式 (深色主题)
   ============================================ */

/* ── Reset & Base ── */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg-primary: #0a0e27;
  --bg-secondary: #111638;
  --bg-card: rgba(255, 255, 255, 0.06);
  --bg-card-hover: rgba(255, 255, 255, 0.1);
  --bg-glass: rgba(255, 255, 255, 0.08);
  --border-color: rgba(255, 255, 255, 0.1);
  --border-light: rgba(255, 255, 255, 0.15);
  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.7);
  --text-muted: rgba(255, 255, 255, 0.45);
  --accent-blue: #6366f1;
  --accent-purple: #8b5cf6;
  --accent-cyan: #06b6d4;
  --accent-gold: #f59e0b;
  --accent-orange: #f97316;
  --gradient-primary: linear-gradient(135deg, #6366f1, #8b5cf6);
  --gradient-hero: linear-gradient(135deg, #0a0e27 0%, #1a1040 50%, #0a0e27 100%);
  --gradient-card-blue: linear-gradient(135deg, #3b82f6, #6366f1);
  --gradient-card-gold: linear-gradient(135deg, #f59e0b, #f97316);
  --gradient-card-orange: linear-gradient(135deg, #f97316, #ef4444);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.15);
  --nav-height: 64px;
  --max-width: 1200px;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  height: auto;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  width: 100%;
}

/* ─ Navigation ── */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(10, 14, 39, 0.9);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  display: flex;
  align-items: center;
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
}

.nav-brand svg {
  width: 28px;
  height: 28px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.nav-links a {
  display: block;
  padding: 8px 16px;
  font-size: 14px;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  transition: color 0.2s, background 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text-primary);
  background: var(--bg-card);
}

.nav-auth {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn-login {
  padding: 8px 24px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  background: var(--gradient-primary);
  border: none;
  border-radius: 20px;
  cursor: pointer;
  transition: opacity 0.2s, transform 0.15s;
}

.btn-login:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

/* Mobile menu toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
  background: none;
  border: none;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}

.nav-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ── Hero Section ── */
.hero {
  padding: calc(var(--nav-height) + 60px) 24px 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
  background: var(--gradient-hero);
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.15) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(6, 182, 212, 0.1) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero h1 {
  font-size: 48px;
  font-weight: 800;
  margin-bottom: 16px;
  position: relative;
  z-index: 1;
}

.hero h1 .highlight {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero .subtitle {
  font-size: 18px;
  color: var(--text-secondary);
  margin-bottom: 32px;
  position: relative;
  z-index: 1;
}

.hero .hero-price {
  font-size: 14px;
  color: var(--text-muted);
  margin-top: 30px;
  margin-bottom: 12px;
  position: relative;
  z-index: 1;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  font-size: 16px;
  font-weight: 600;
  color: #fff;
  background: var(--gradient-primary);
  border: none;
  border-radius: 28px;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.2s;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  background: var(--bg-glass);
  border: 1px solid var(--border-light);
  border-radius: 28px;
  cursor: pointer;
  transition: background 0.2s, transform 0.15s;
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  transform: translateY(-2px);
}

/* ── Section Common ─ */
.section {
  padding: 80px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-header h2 {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 12px;
}

.section-header p {
  font-size: 16px;
  color: var(--text-secondary);
}

.section-dark {
  background: var(--bg-secondary);
}

/* ── Feature Cards Grid ── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  text-align: center;
  transition: transform 0.2s, border-color 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-blue);
  box-shadow: var(--shadow-glow);
}

.feature-icon {
  width: 52px;
  height: 52px;
  margin: 0 auto 16px;
  background: var(--bg-glass);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
}

.feature-icon svg {
  width: 26px;
  height: 26px;
  color: var(--accent-blue);
}

.feature-card h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 6px;
}

.feature-card p {
  font-size: 13px;
  color: var(--text-muted);
}

/* ── Pricing Cards ─ */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}

.pricing-grid-2 {
  grid-template-columns: repeat(2, 1fr);
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
  margin-bottom: 48px;
}

.trial-notice {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.3);
  border-radius: var(--radius-md);
  font-size: 14px;
  color: var(--text-secondary);
  text-align: center;
  justify-content: center;
}

.trial-contact {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  margin-top: 12px;
  font-size: 14px;
  color: var(--text-primary);
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 36px 28px;
  position: relative;
  transition: transform 0.2s, box-shadow 0.2s;
}

.pricing-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
}

.pricing-card.featured {
  border-color: var(--accent-gold);
  background: linear-gradient(180deg, rgba(245, 158, 11, 0.08) 0%, var(--bg-card) 100%);
}

.pricing-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  padding: 4px 16px;
  font-size: 12px;
  font-weight: 600;
  border-radius: 12px;
  background: var(--gradient-card-gold);
  color: #fff;
}

.pricing-card .plan-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}

.pricing-card .plan-icon.blue {
  background: var(--gradient-card-blue);
}

.pricing-card .plan-icon.gold {
  background: var(--gradient-card-gold);
}

.pricing-card .plan-icon.orange {
  background: var(--gradient-card-orange);
}

.pricing-card .plan-icon svg {
  width: 22px;
  height: 22px;
  color: #fff;
}

.pricing-card .plan-name {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 4px;
  text-align: center;
}

.pricing-card .plan-desc {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 16px;
  text-align: center;
}

.pricing-card .plan-price {
  font-size: 40px;
  font-weight: 800;
  margin-bottom: 4px;
  text-align: center;
}

.pricing-card .plan-price .currency {
  font-size: 20px;
  font-weight: 600;
}

.pricing-card .plan-price .period {
  font-size: 14px;
  font-weight: 400;
  color: var(--text-secondary);
}

.pricing-card .plan-features {
  list-style: none;
  margin: 20px 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: center;
}

.pricing-card .plan-features li {
  font-size: 14px;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 8px;
  justify-content: center;
}

.pricing-card .plan-features li::before {
  content: '✓';
  color: var(--accent-cyan);
  font-weight: 700;
  flex-shrink: 0;
}

.pricing-card .plan-btn {
  display: block;
  width: 100%;
  padding: 12px;
  font-size: 15px;
  font-weight: 600;
  text-align: center;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: opacity 0.2s, transform 0.15s;
}

.pricing-card .plan-btn:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.pricing-card .plan-btn.btn-outline {
  background: transparent;
  border: 1px solid var(--border-light);
  color: var(--text-primary);
}

.pricing-card .plan-btn.btn-gold {
  background: var(--gradient-card-gold);
  color: #fff;
}

.pricing-card .plan-btn.btn-orange {
  background: var(--gradient-card-orange);
  color: #fff;
}

/* ── Comparison Table ─ */
.comparison-table-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 600px;
}

.comparison-table th,
.comparison-table td {
  padding: 14px 20px;
  text-align: center;
  font-size: 14px;
  border-bottom: 1px solid var(--border-color);
}

.comparison-table th {
  background: var(--bg-glass);
  font-weight: 600;
  color: var(--text-primary);
}

.comparison-table td {
  color: var(--text-secondary);
}

.comparison-table tr:last-child td {
  border-bottom: none;
}

.comparison-table .check {
  color: var(--accent-cyan);
  font-weight: 700;
}

.comparison-table .cross {
  color: var(--text-muted);
}

/* ── Video Cards Grid ── */
.video-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 32px;
  align-items: center;
}

.video-search {
  flex: 1;
  min-width: 200px;
  max-width: 360px;
  position: relative;
}

.video-search input {
  width: 100%;
  padding: 10px 16px 10px 40px;
  font-size: 14px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  outline: none;
  transition: border-color 0.2s;
}

.video-search input::placeholder {
  color: var(--text-muted);
}

.video-search input:focus {
  border-color: var(--accent-blue);
}

.video-search svg {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  width: 18px;
  height: 18px;
  color: var(--text-muted);
}

.filter-tag {
  padding: 8px 18px;
  font-size: 13px;
  font-weight: 500;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
}

.filter-tag:hover,
.filter-tag.active {
  background: var(--accent-blue);
  border-color: var(--accent-blue);
  color: #fff;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.video-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: transform 0.2s, border-color 0.2s, box-shadow 0.2s;
  cursor: pointer;
}

.video-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-blue);
  box-shadow: var(--shadow-glow);
}

.video-thumb {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: var(--bg-secondary);
  overflow: hidden;
}

.video-thumb img,
.video-thumb video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.video-thumb .play-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.3);
  opacity: 0.45;
  transition: opacity 0.2s;
}

.video-card:hover .play-overlay {
  opacity: 1;
}

.play-overlay svg {
  width: 48px;
  height: 48px;
  color: #fff;
  filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.5));
}

.video-badge {
  position: absolute;
  top: 10px;
  right: 10px;
  padding: 3px 10px;
  font-size: 11px;
  font-weight: 600;
  border-radius: 10px;
}

.video-badge.free {
  background: rgba(6, 182, 212, 0.9);
  color: #fff;
}

.video-badge.member {
  background: rgba(245, 158, 11, 0.9);
  color: #fff;
}

.video-duration {
  position: absolute;
  bottom: 10px;
  right: 10px;
  padding: 2px 8px;
  font-size: 12px;
  background: rgba(0, 0, 0, 0.7);
  border-radius: 4px;
  color: #fff;
}

.video-info {
  padding: 14px 16px;
}

.video-info h3 {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 6px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.video-meta {
  font-size: 12px;
  color: var(--text-muted);
  display: flex;
  gap: 12px;
}

/* ── Cases Showcase ── */
.cases-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.case-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: transform 0.2s, border-color 0.2s;
}

.case-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-blue);
}

.case-thumb {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: var(--bg-secondary);
  overflow: hidden;
}

.case-thumb video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.case-thumb .play-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.3);
  opacity: 0.45;
  transition: opacity 0.2s;
}

.case-card:hover .play-overlay {
  opacity: 1;
}

/* 触屏设备（无 hover）默认常显半透明播放遮罩；桌面端（有 hover）默认隐藏、悬停时显示 */
@media (hover: hover) {
  .video-thumb .play-overlay,
  .case-thumb .play-overlay {
    opacity: 0;
  }
}

.play-overlay svg {
  width: 48px;
  height: 48px;
  color: #fff;
  filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.5));
}

.case-info {
  padding: 16px;
}

.case-info h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 4px;
}

.case-info p {
  font-size: 13px;
  color: var(--text-muted);
}

/* ── Quick Links ─ */
.quick-links {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.quick-link-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  text-align: center;
  transition: transform 0.2s, border-color 0.2s;
  display: block;
}

.quick-link-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-blue);
}

.quick-link-card .ql-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 14px;
  background: var(--bg-glass);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
}

.quick-link-card .ql-icon svg {
  width: 28px;
  height: 28px;
  color: var(--accent-blue);
}

.quick-link-card h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.quick-link-card p {
  font-size: 13px;
  color: var(--text-muted);
}

/* ── Download Page ── */
.download-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  max-width: 700px;
  margin: 0 auto 40px;
}

.dl-card {
  display: flex;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: border-color 0.2s, transform 0.15s, box-shadow 0.2s;
}

.dl-card:hover {
  border-color: var(--accent-blue);
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

.dl-card .dl-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  background: var(--bg-glass);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-right: 18px;
  flex-shrink: 0;
}

.dl-card .dl-icon svg {
  width: 26px;
  height: 26px;
  color: var(--accent-blue);
}

.dl-card .dl-info {
  flex: 1;
}

.dl-card .dl-info h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
}

.dl-card .dl-info p {
  font-size: 13px;
  color: var(--text-muted);
}

.dl-card .dl-arrow {
  flex-shrink: 0;
  margin-left: 12px;
  color: var(--accent-blue);
}

.dl-card .dl-arrow svg {
  width: 22px;
  height: 22px;
}

/* Version log */
.version-log {
  max-width: 700px;
  margin: 0 auto;
}

.version-log h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 24px;
  text-align: center;
}

.version-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  margin-bottom: 16px;
}

.version-item .ver-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}

.version-item .ver-tag {
  font-size: 14px;
  font-weight: 600;
  color: var(--accent-blue);
}

.version-item .ver-date {
  font-size: 13px;
  color: var(--text-muted);
}

.version-item ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.version-item ul li {
  font-size: 13px;
  color: var(--text-secondary);
  padding-left: 16px;
  position: relative;
}

.version-item ul li::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--accent-blue);
}

/* ── FAQ ── */
.faq-categories {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin-bottom: 36px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
  transition: border-color 0.2s;
}

.faq-item:hover {
  border-color: var(--border-light);
}

.faq-question {
  width: 100%;
  padding: 18px 24px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  background: none;
  border: none;
  text-align: left;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.faq-question svg {
  width: 18px;
  height: 18px;
  color: var(--text-muted);
  transition: transform 0.3s;
  flex-shrink: 0;
}

.faq-item.open .faq-question svg {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
}

.faq-item.open .faq-answer {
  max-height: 500px;
  padding: 0 24px 18px;
}

.faq-answer p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ── Contact / Form ── */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}

.contact-info-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.contact-info-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.contact-info-item .ci-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: var(--bg-glass);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.contact-info-item .ci-icon svg {
  width: 22px;
  height: 22px;
  color: var(--accent-blue);
}

.contact-info-item h4 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 4px;
}

.contact-info-item p {
  font-size: 14px;
  color: var(--text-secondary);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 6px;
  color: var(--text-secondary);
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px 16px;
  font-size: 14px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  outline: none;
  transition: border-color 0.2s;
  font-family: var(--font-family);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  border-color: var(--accent-blue);
}

.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

.form-group select option {
  background: var(--bg-secondary);
}

/* ── Learning Center ── */
.tutorial-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.tutorial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: transform 0.2s, border-color 0.2s;
}

.tutorial-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-blue);
}

.tutorial-card .tc-tag {
  display: inline-block;
  padding: 3px 10px;
  font-size: 11px;
  font-weight: 600;
  border-radius: 10px;
  margin-bottom: 12px;
}

.tutorial-card .tc-tag.free {
  background: rgba(6, 182, 212, 0.2);
  color: var(--accent-cyan);
}

.tutorial-card .tc-tag.member {
  background: rgba(245, 158, 11, 0.2);
  color: var(--accent-gold);
}

.tutorial-card h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

.tutorial-card p {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 14px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.tutorial-card .tc-meta {
  font-size: 12px;
  color: var(--text-muted);
  display: flex;
  justify-content: space-between;
}

/* ── Page Header (sub pages) ── */
.page-header {
  padding: calc(var(--nav-height) + 48px) 24px 48px;
  text-align: center;
  background: var(--gradient-hero);
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: '';
  position: absolute;
  top: -40%;
  right: -15%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.12) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.page-header h1 {
  font-size: 36px;
  font-weight: 800;
  margin-bottom: 12px;
  position: relative;
  z-index: 1;
}

.page-header p {
  font-size: 16px;
  color: var(--text-secondary);
  position: relative;
  z-index: 1;
}

/* ── Footer ── */
.site-footer {
  margin-top: auto;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 48px 0 24px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 36px;
}

.footer-brand h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
  text-align: center;
}

.footer-brand p {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.7;
  text-align: center;
}

.footer-col h4 {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--text-primary);
  text-align: center;
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: center;
}

.footer-col ul li a {
  font-size: 13px;
  color: var(--text-muted);
  transition: color 0.2s;
}

.footer-col ul li a:hover {
  color: var(--text-primary);
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-bottom p {
  font-size: 12px;
  color: var(--text-muted);
}

.footer-bottom a {
  color: var(--text-muted);
  transition: color 0.2s;
}

.footer-bottom a:hover {
  color: var(--text-secondary);
}

/* ── Mobile Notice ── */
.mobile-notice {
  display: none;
  text-align: center;
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 14px;
  color: var(--text-secondary);
}

/* ── Contact CTA ── */
.contact-cta-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  max-width: 600px;
  margin: 0 auto;
}

.contact-cta-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  text-align: center;
  transition: transform 0.2s, border-color 0.2s, box-shadow 0.2s;
}

.contact-cta-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-blue);
  box-shadow: var(--shadow-glow);
}

.contact-cta-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 14px;
  background: #fff;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
}

.contact-cta-icon svg {
  width: 28px;
  height: 28px;
  color: var(--accent-blue);
}

.contact-cta-card h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 16px;
}

.contact-qr {
  width: 130px;
  height: 130px;
  border-radius: var(--radius-md);
  object-fit: cover;
  object-position: center 80%;
  margin: 0 auto 12px;
  display: block;
  background: #fff;
  padding: 6px;
}

.contact-qq-num {
  font-size: 28px;
  font-weight: 700;
  color: var(--accent-blue);
  margin: 12px 0;
  letter-spacing: 2px;
}

.contact-cta-hint {
  font-size: 13px;
  color: var(--text-muted);
}

/* ── Footer Contact ── */
.footer-contact {
  text-align: center;
}

.footer-qr-wrap {
  margin-bottom: 8px;
}

.footer-qr {
  width: 100px;
  height: 100px;
  border-radius: var(--radius-sm);
  object-fit: cover;
  object-position: center 80%;
  background: #fff;
  padding: 4px;
  display: block;
  margin: 0 auto 4px;
}

.footer-qr-label {
  font-size: 12px;
  color: var(--text-muted);
}

.footer-qq {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* ── Responsive ── */
@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .video-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .quick-links {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    height: calc(100vh - var(--nav-height));
    background: rgba(10, 14, 39, 0.92);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 24px;
    gap: 4px;
    z-index: 1001;
    overflow-y: auto;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    padding: 16px;
    font-size: 16px;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
  }

  .nav-links a:last-child {
    border-bottom: none;
  }

  .nav-links a:hover,
  .nav-links a.active {
    background: var(--bg-card);
  }

  .nav-toggle {
    display: flex;
  }

  .nav-auth {
    display: none;
  }

  .hero h1 {
    font-size: 32px;
  }

  .hero .subtitle {
    font-size: 16px;
  }

  .section-header h2 {
    font-size: 24px;
  }

  .pricing-grid,
  .pricing-grid-2 {
    grid-template-columns: 1fr;
    max-width: 400px;
    margin-left: auto;
    margin-right: auto;
  }

  .video-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .cases-grid {
    grid-template-columns: 1fr;
  }

  .tutorial-grid {
    grid-template-columns: 1fr;
  }

  .download-cards {
    grid-template-columns: 1fr;
  }

  .contact-grid {
    grid-template-columns: 1fr;
  }

  .contact-cta-grid {
    grid-template-columns: 1fr;
    max-width: 320px;
  }

  .quick-links {
    grid-template-columns: 1fr 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
    gap: 8px;
  }

  .footer-bottom p {
    font-size: 11px;
  }

  .page-header h1 {
    font-size: 28px;
  }

  .mobile-notice {
    display: block;
  }

  .desktop-only {
    display: none !important;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: calc(var(--nav-height) + 40px) 16px 48px;
  }

  .hero h1 {
    font-size: 26px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .btn-primary, .btn-secondary {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }

  .video-grid {
    grid-template-columns: 1fr;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .quick-links {
    grid-template-columns: 1fr;
  }

  .video-filters {
    flex-direction: column;
    align-items: stretch;
  }

  .video-search {
    max-width: 100%;
  }

  .section {
    padding: 48px 0;
  }

  .container {
    padding: 0 16px;
  }

  .site-footer {
    padding: 36px 0 20px;
  }
}