/* ========================================
   17C视频社区 - 暗黑潮流风格主样式
   ======================================== */

:root {
  --color-bg: #080810;
  --color-bg2: #0d0d1a;
  --color-bg3: #12121f;
  --color-gold: #f0c040;
  --color-gold2: #ffd700;
  --color-purple: #9b59b6;
  --color-purple2: #7c3aed;
  --color-neon: #bf00ff;
  --color-text: #e8e8f0;
  --color-text2: #a0a0c0;
  --color-border: rgba(155,89,182,0.25);
  --color-card: rgba(15,15,28,0.92);
  --grad-gold-purple: linear-gradient(135deg, #f0c040 0%, #9b59b6 50%, #bf00ff 100%);
  --grad-dark: linear-gradient(180deg, #080810 0%, #0d0d1a 100%);
  --shadow-neon: 0 0 20px rgba(191,0,255,0.4), 0 0 40px rgba(240,192,64,0.2);
  --shadow-card: 0 4px 32px rgba(0,0,0,0.6);
  --radius: 12px;
  --radius-sm: 6px;
  --transition: all 0.3s cubic-bezier(0.4,0,0.2,1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; font-size: 16px; }

body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
  line-height: 1.7;
  overflow-x: hidden;
}

/* ---- 粒子背景 ---- */
#particles-canvas {
  position: fixed; top: 0; left: 0;
  width: 100%; height: 100%;
  pointer-events: none; z-index: 0;
  opacity: 0.35;
}

/* ---- 导航 ---- */
.site-nav {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(8,8,16,0.92);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
  padding: 0 24px;
  height: 64px;
  display: flex; align-items: center; justify-content: space-between;
}

.nav-logo {
  display: flex; align-items: center; gap: 10px;
  text-decoration: none;
}

.nav-logo-text {
  font-size: 1.6rem; font-weight: 900; letter-spacing: 2px;
  background: var(--grad-gold-purple);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: none;
  filter: drop-shadow(0 0 8px rgba(240,192,64,0.5));
}

.nav-menu {
  display: flex; align-items: center; gap: 4px;
  list-style: none;
}

.nav-menu a {
  display: block; padding: 8px 14px;
  color: var(--color-text2); text-decoration: none;
  font-size: 0.9rem; font-weight: 500;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  position: relative;
}

.nav-menu a::after {
  content: ''; position: absolute; bottom: 4px; left: 50%; right: 50%;
  height: 2px; background: var(--grad-gold-purple);
  border-radius: 2px; transition: var(--transition);
}

.nav-menu a:hover { color: var(--color-gold); }
.nav-menu a:hover::after { left: 14px; right: 14px; }

.nav-toggle {
  display: none; flex-direction: column; gap: 5px;
  cursor: pointer; padding: 6px;
  background: none; border: none;
}
.nav-toggle span {
  display: block; width: 24px; height: 2px;
  background: var(--color-gold); border-radius: 2px;
  transition: var(--transition);
}

/* ---- 搜索框 ---- */
.search-bar-wrap {
  background: var(--color-bg2);
  border-bottom: 1px solid var(--color-border);
  padding: 12px 24px;
  margin-top: 64px;
  display: flex; justify-content: center;
}

.search-bar {
  display: flex; align-items: center;
  width: 100%; max-width: 680px;
  background: var(--color-bg3);
  border: 1px solid var(--color-border);
  border-radius: 40px;
  padding: 0 20px;
  gap: 10px;
  transition: var(--transition);
}

.search-bar:focus-within {
  border-color: var(--color-purple);
  box-shadow: 0 0 0 3px rgba(155,89,182,0.2);
}

.search-bar input {
  flex: 1; background: none; border: none; outline: none;
  color: var(--color-text); font-size: 0.95rem;
  padding: 12px 0;
}

.search-bar input::placeholder { color: var(--color-text2); }

.search-btn {
  background: var(--grad-gold-purple);
  border: none; border-radius: 20px;
  color: #fff; font-size: 0.85rem; font-weight: 600;
  padding: 7px 18px; cursor: pointer;
  transition: var(--transition);
}
.search-btn:hover { opacity: 0.85; transform: scale(1.04); }

/* ---- 通用容器 ---- */
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.section { padding: 80px 0; position: relative; z-index: 1; }
.section-alt { background: var(--color-bg2); }

.section-header { text-align: center; margin-bottom: 48px; }
.section-tag {
  display: inline-block;
  background: rgba(155,89,182,0.15);
  border: 1px solid var(--color-purple);
  color: var(--color-purple);
  font-size: 0.78rem; font-weight: 700; letter-spacing: 2px;
  padding: 4px 14px; border-radius: 20px;
  margin-bottom: 12px; text-transform: uppercase;
}
.section-title {
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 800; line-height: 1.2;
  background: var(--grad-gold-purple);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.section-desc {
  color: var(--color-text2); font-size: 1rem;
  margin-top: 12px; max-width: 560px; margin-left: auto; margin-right: auto;
}

/* ---- 首屏Banner ---- */
.hero {
  min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  position: relative; overflow: hidden;
  padding-top: 120px;
}

.hero-bg {
  position: absolute; inset: 0;
  background-image: url('../images/banner_hero.jpg');
  background-size: cover; background-position: center;
  filter: brightness(0.35) saturate(1.4);
  z-index: 0;
}

.hero-overlay {
  position: absolute; inset: 0;
  background: radial-gradient(ellipse at center, rgba(155,89,182,0.18) 0%, rgba(8,8,16,0.7) 70%);
  z-index: 1;
}

.hero-content {
  position: relative; z-index: 2;
  text-align: center; max-width: 860px; padding: 0 24px;
}

.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: rgba(240,192,64,0.1);
  border: 1px solid rgba(240,192,64,0.4);
  color: var(--color-gold); font-size: 0.82rem; font-weight: 600;
  padding: 6px 18px; border-radius: 20px; margin-bottom: 24px;
  letter-spacing: 1px;
}

.hero-badge-dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--color-gold);
  animation: pulse 1.5s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.4); }
}

.hero-title {
  font-size: clamp(2.4rem, 6vw, 5rem);
  font-weight: 900; line-height: 1.1;
  letter-spacing: -1px; margin-bottom: 20px;
}

.hero-title .brand {
  background: var(--grad-gold-purple);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 0 20px rgba(240,192,64,0.5));
}

.hero-sub {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--color-text2); margin-bottom: 36px; line-height: 1.6;
}

.hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

.btn-primary {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--grad-gold-purple);
  color: #fff; font-size: 1rem; font-weight: 700;
  padding: 14px 32px; border-radius: 40px;
  text-decoration: none; border: none; cursor: pointer;
  transition: var(--transition);
  box-shadow: var(--shadow-neon);
}
.btn-primary:hover { transform: translateY(-3px) scale(1.04); box-shadow: 0 0 30px rgba(191,0,255,0.6); }

.btn-secondary {
  display: inline-flex; align-items: center; gap: 8px;
  background: transparent;
  color: var(--color-gold); font-size: 1rem; font-weight: 700;
  padding: 13px 32px; border-radius: 40px;
  text-decoration: none;
  border: 2px solid var(--color-gold);
  cursor: pointer; transition: var(--transition);
}
.btn-secondary:hover { background: rgba(240,192,64,0.12); transform: translateY(-3px); }

.hero-stats {
  display: flex; gap: 40px; justify-content: center;
  margin-top: 56px; flex-wrap: wrap;
}

.hero-stat { text-align: center; }
.hero-stat-num {
  font-size: 2rem; font-weight: 900;
  background: var(--grad-gold-purple);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-stat-label { font-size: 0.82rem; color: var(--color-text2); margin-top: 4px; }

/* ---- 视频卡片 ---- */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
}

.video-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
  cursor: pointer;
}

.video-card:hover {
  transform: translateY(-6px);
  border-color: var(--color-purple);
  box-shadow: var(--shadow-neon);
}

.video-thumb {
  position: relative; aspect-ratio: 16/9;
  overflow: hidden; background: #0d0d1a;
}

.video-thumb img {
  width: 100%; height: 100%; object-fit: cover;
  transition: transform 0.4s ease;
}

.video-card:hover .video-thumb img { transform: scale(1.06); }

.video-play-btn {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  background: rgba(0,0,0,0.5);
  opacity: 0; transition: var(--transition);
}

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

.play-icon {
  width: 56px; height: 56px;
  background: var(--grad-gold-purple);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 0 24px rgba(191,0,255,0.6);
  transition: transform 0.2s;
}

.play-icon::after {
  content: '';
  width: 0; height: 0;
  border-style: solid;
  border-width: 9px 0 9px 18px;
  border-color: transparent transparent transparent #fff;
  margin-left: 4px;
}

.video-card:hover .play-icon { transform: scale(1.12); }

.video-duration {
  position: absolute; bottom: 8px; right: 8px;
  background: rgba(0,0,0,0.75);
  color: #fff; font-size: 0.75rem; font-weight: 600;
  padding: 2px 8px; border-radius: 4px;
}

.video-tag {
  position: absolute; top: 8px; left: 8px;
  background: var(--grad-gold-purple);
  color: #fff; font-size: 0.7rem; font-weight: 700;
  padding: 2px 10px; border-radius: 4px;
  letter-spacing: 0.5px;
}

.video-info { padding: 14px 16px; }
.video-title {
  font-size: 0.95rem; font-weight: 700;
  color: var(--color-text); margin-bottom: 8px;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical;
  overflow: hidden; line-height: 1.4;
}

.video-meta {
  display: flex; gap: 14px; align-items: center;
  font-size: 0.78rem; color: var(--color-text2);
}

.video-meta span { display: flex; align-items: center; gap: 4px; }
.video-meta .icon { font-size: 0.85rem; }

/* ---- 弹幕社区 ---- */
.danmaku-wrap {
  background: var(--color-bg3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px;
  overflow: hidden; position: relative;
  height: 80px;
}

.danmaku-track {
  display: flex; gap: 32px;
  white-space: nowrap;
  animation: danmaku-scroll 18s linear infinite;
}

@keyframes danmaku-scroll {
  0% { transform: translateX(100%); }
  100% { transform: translateX(-100%); }
}

.danmaku-item {
  display: inline-flex; align-items: center; gap: 8px;
  background: rgba(155,89,182,0.12);
  border: 1px solid rgba(155,89,182,0.3);
  color: var(--color-text); font-size: 0.88rem;
  padding: 6px 16px; border-radius: 20px;
  white-space: nowrap;
}

/* ---- 话题标签 ---- */
.topic-grid {
  display: flex; flex-wrap: wrap; gap: 12px;
  justify-content: center; margin-bottom: 32px;
}

.topic-tag {
  background: rgba(155,89,182,0.12);
  border: 1px solid var(--color-purple);
  color: var(--color-purple);
  font-size: 0.88rem; font-weight: 600;
  padding: 8px 20px; border-radius: 20px;
  cursor: pointer; transition: var(--transition);
  text-decoration: none;
}
.topic-tag:hover {
  background: var(--color-purple);
  color: #fff;
  box-shadow: 0 0 16px rgba(155,89,182,0.5);
}

/* ---- AI工具卡片 ---- */
.ai-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 20px;
}

.ai-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px 20px;
  text-align: center;
  transition: var(--transition);
  cursor: pointer;
}

.ai-card:hover {
  border-color: var(--color-gold);
  box-shadow: 0 0 24px rgba(240,192,64,0.25);
  transform: translateY(-4px);
}

.ai-icon {
  font-size: 2.4rem; margin-bottom: 14px;
  display: block;
}

.ai-card h3 {
  font-size: 1rem; font-weight: 700;
  color: var(--color-gold); margin-bottom: 8px;
}

.ai-card p { font-size: 0.85rem; color: var(--color-text2); line-height: 1.5; }

/* ---- 专家卡片 ---- */
.expert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 24px;
}

.expert-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px 20px;
  text-align: center;
  transition: var(--transition);
}

.expert-card:hover {
  border-color: var(--color-purple);
  box-shadow: var(--shadow-neon);
  transform: translateY(-4px);
}

.expert-avatar {
  width: 90px; height: 90px;
  border-radius: 50%; object-fit: cover;
  border: 3px solid transparent;
  background-clip: padding-box;
  box-shadow: 0 0 0 3px var(--color-purple);
  margin: 0 auto 16px;
  display: block;
}

.expert-name { font-size: 1.05rem; font-weight: 700; color: var(--color-gold); margin-bottom: 4px; }
.expert-title { font-size: 0.82rem; color: var(--color-purple); margin-bottom: 10px; }
.expert-desc { font-size: 0.83rem; color: var(--color-text2); line-height: 1.5; }

/* ---- 评价卡片 ---- */
.review-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}

.review-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  transition: var(--transition);
}

.review-card:hover {
  border-color: var(--color-gold);
  transform: translateY(-3px);
}

.review-stars { color: var(--color-gold); font-size: 1rem; margin-bottom: 12px; letter-spacing: 2px; }
.review-content { font-size: 0.9rem; color: var(--color-text2); line-height: 1.6; margin-bottom: 16px; font-style: italic; }
.review-user { display: flex; align-items: center; gap: 10px; }
.review-avatar {
  width: 38px; height: 38px; border-radius: 50%;
  background: var(--grad-gold-purple);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.9rem; font-weight: 700; color: #fff;
  flex-shrink: 0;
}
.review-name { font-size: 0.88rem; font-weight: 700; color: var(--color-text); }
.review-date { font-size: 0.75rem; color: var(--color-text2); margin-top: 2px; }

/* ---- FAQ ---- */
.faq-list { max-width: 800px; margin: 0 auto; }

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

.faq-item.active { border-color: var(--color-purple); }

.faq-question {
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 22px; cursor: pointer;
  font-size: 0.95rem; font-weight: 600; color: var(--color-text);
  user-select: none;
}

.faq-question:hover { color: var(--color-gold); }

.faq-arrow {
  width: 22px; height: 22px;
  border: 2px solid var(--color-purple);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.75rem; color: var(--color-purple);
  transition: transform 0.3s;
  flex-shrink: 0;
}

.faq-item.active .faq-arrow { transform: rotate(180deg); }

.faq-answer {
  max-height: 0; overflow: hidden;
  transition: max-height 0.35s ease, padding 0.3s;
  padding: 0 22px;
  font-size: 0.88rem; color: var(--color-text2); line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 200px;
  padding: 0 22px 18px;
}

/* ---- 合作伙伴 ---- */
.partner-grid {
  display: flex; flex-wrap: wrap; gap: 16px;
  justify-content: center; align-items: center;
}

.partner-logo {
  background: var(--color-bg3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 16px 28px;
  font-size: 0.9rem; font-weight: 700;
  color: var(--color-text2);
  transition: var(--transition);
  cursor: default;
}

.partner-logo:hover {
  border-color: var(--color-gold);
  color: var(--color-gold);
  box-shadow: 0 0 12px rgba(240,192,64,0.2);
}

/* ---- 联系模块 ---- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px; align-items: start;
}

.contact-info h3 {
  font-size: 1.4rem; font-weight: 800;
  color: var(--color-gold); margin-bottom: 20px;
}

.contact-item {
  display: flex; align-items: flex-start; gap: 14px;
  margin-bottom: 18px;
}

.contact-icon {
  width: 40px; height: 40px;
  background: rgba(155,89,182,0.15);
  border: 1px solid var(--color-purple);
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem; flex-shrink: 0;
}

.contact-text strong { display: block; font-size: 0.85rem; color: var(--color-gold); margin-bottom: 2px; }
.contact-text span { font-size: 0.88rem; color: var(--color-text2); }

.qr-box {
  background: var(--color-bg3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px; text-align: center;
}

.qr-placeholder {
  width: 140px; height: 140px;
  background: var(--grad-gold-purple);
  border-radius: 12px; margin: 0 auto 14px;
  display: flex; align-items: center; justify-content: center;
  font-size: 2.5rem;
}

.qr-box p { font-size: 0.85rem; color: var(--color-text2); }

/* ---- 页脚 ---- */
.site-footer {
  background: #050508;
  border-top: 1px solid var(--color-border);
  padding: 48px 0 24px;
  position: relative; z-index: 1;
}

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

.footer-brand .nav-logo-text { font-size: 1.8rem; display: block; margin-bottom: 14px; }
.footer-brand p { font-size: 0.85rem; color: var(--color-text2); line-height: 1.7; max-width: 280px; }

.footer-col h4 {
  font-size: 0.9rem; font-weight: 700;
  color: var(--color-gold); margin-bottom: 16px;
  letter-spacing: 1px;
}

.footer-links { list-style: none; }
.footer-links li { margin-bottom: 8px; }
.footer-links a {
  font-size: 0.85rem; color: var(--color-text2);
  text-decoration: none; transition: color 0.2s;
}
.footer-links a:hover { color: var(--color-gold); }

.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding-top: 24px;
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 12px;
}

.footer-copy { font-size: 0.82rem; color: var(--color-text2); }
.footer-copy a { color: var(--color-purple); text-decoration: none; }
.footer-copy a:hover { color: var(--color-gold); }

.footer-social { display: flex; gap: 12px; }
.social-btn {
  width: 36px; height: 36px;
  background: var(--color-bg3);
  border: 1px solid var(--color-border);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.9rem; color: var(--color-text2);
  text-decoration: none; transition: var(--transition);
}
.social-btn:hover {
  border-color: var(--color-gold);
  color: var(--color-gold);
  box-shadow: 0 0 12px rgba(240,192,64,0.3);
}

/* ---- 内页面包屑 ---- */
.breadcrumb {
  padding: 12px 0;
  font-size: 0.82rem; color: var(--color-text2);
}
.breadcrumb a { color: var(--color-purple); text-decoration: none; }
.breadcrumb a:hover { color: var(--color-gold); }
.breadcrumb span { margin: 0 8px; }

/* ---- 内页Banner ---- */
.page-hero {
  padding: 100px 0 60px;
  background: linear-gradient(180deg, rgba(155,89,182,0.08) 0%, transparent 100%);
  text-align: center;
}

.page-hero h1 {
  font-size: clamp(1.8rem, 4vw, 3rem);
  font-weight: 900;
  background: var(--grad-gold-purple);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 12px;
}

.page-hero p { font-size: 1rem; color: var(--color-text2); max-width: 560px; margin: 0 auto; }

/* ---- 标签徽章 ---- */
.badge {
  display: inline-block;
  font-size: 0.72rem; font-weight: 700;
  padding: 2px 10px; border-radius: 4px;
  letter-spacing: 0.5px;
}
.badge-hot { background: rgba(240,192,64,0.15); color: var(--color-gold); border: 1px solid var(--color-gold); }
.badge-new { background: rgba(155,89,182,0.15); color: var(--color-purple); border: 1px solid var(--color-purple); }
.badge-ai { background: rgba(0,200,255,0.1); color: #00c8ff; border: 1px solid #00c8ff; }

/* ---- 滚动进度条 ---- */
.scroll-progress {
  position: fixed; top: 64px; left: 0; right: 0;
  height: 2px; background: transparent; z-index: 999;
}
.scroll-progress-bar {
  height: 100%;
  background: var(--grad-gold-purple);
  width: 0%; transition: width 0.1s;
}

/* ---- 回到顶部 ---- */
.back-top {
  position: fixed; bottom: 32px; right: 24px;
  width: 44px; height: 44px;
  background: var(--grad-gold-purple);
  border-radius: 50%; border: none;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer; z-index: 999;
  box-shadow: var(--shadow-neon);
  opacity: 0; pointer-events: none;
  transition: var(--transition);
  color: #fff; font-size: 1.1rem;
  text-decoration: none;
}
.back-top.visible { opacity: 1; pointer-events: auto; }
.back-top:hover { transform: translateY(-4px); }

/* ---- 分割线装饰 ---- */
.neon-divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-purple), var(--color-gold), transparent);
  margin: 0; border: none;
}

/* ---- 懒加载占位 ---- */
img[loading="lazy"] { background: var(--color-bg3); }

/* ---- 响应式 ---- */
@media (max-width: 1024px) {
  .footer-top { grid-template-columns: 1fr 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .nav-menu { display: none; flex-direction: column; position: absolute; top: 64px; left: 0; right: 0; background: rgba(8,8,16,0.98); padding: 16px; border-bottom: 1px solid var(--color-border); }
  .nav-menu.open { display: flex; }
  .nav-toggle { display: flex; }
  .hero-stats { gap: 24px; }
  .footer-top { grid-template-columns: 1fr; gap: 24px; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .video-grid { grid-template-columns: 1fr 1fr; }
  .expert-grid { grid-template-columns: 1fr 1fr; }
  .review-grid { grid-template-columns: 1fr; }
  .ai-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 480px) {
  .video-grid { grid-template-columns: 1fr; }
  .expert-grid { grid-template-columns: 1fr; }
  .ai-grid { grid-template-columns: 1fr; }
  .hero-btns { flex-direction: column; align-items: center; }
  .container { padding: 0 16px; }
  .section { padding: 56px 0; }
}

/* ---- 动画 ---- */
.fade-in { opacity: 0; transform: translateY(24px); transition: opacity 0.6s ease, transform 0.6s ease; }
.fade-in.visible { opacity: 1; transform: none; }

.glow-text {
  text-shadow: 0 0 20px rgba(240,192,64,0.5), 0 0 40px rgba(155,89,182,0.3);
}