/* ============================================
   51视频 - 原创样式表
   品牌：51视频 | oemmxL.cn
   配色：深紫黑 + 活力橙 + 青绿
   ============================================ */

/* === CSS Variables === */
:root {
  --primary-dark: #1A0B2E;
  --primary-deep: #11001C;
  --secondary-orange: #FF6B35;
  --accent-cyan: #00D4AA;
  --gradient-start: #2D1B69;
  --gradient-end: #11001C;
  --text-light: #E8E0F0;
  --text-muted: #A89BBF;
  --card-bg: rgba(45, 27, 105, 0.55);
  --card-border: rgba(255, 107, 53, 0.2);
  --card-hover: rgba(0, 212, 170, 0.12);
  --shadow-glow: rgba(255, 107, 53, 0.3);
  --font-main: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --transition: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-main);
  background: linear-gradient(175deg, var(--gradient-start), var(--gradient-end));
  color: var(--text-light);
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
}
a { color: var(--accent-cyan); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--secondary-orange); }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
h1, h2, h3, h4, h5, h6 { line-height: 1.3; font-weight: 700; }

/* === Container === */
.container { max-width: 1280px; margin: 0 auto; padding: 0 20px; }

/* === Header / Navigation === */
.site-header {
  position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
  background: rgba(26, 11, 46, 0.92);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(255, 107, 53, 0.15);
  transition: background var(--transition);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  max-width: 1280px; margin: 0 auto; padding: 0 20px; height: 68px;
}
.logo-link { display: flex; align-items: center; gap: 10px; }
.logo-link img { height: 42px; width: auto; }
.logo-text { font-size: 1.4rem; font-weight: 800; color: var(--secondary-orange); letter-spacing: 1px; }
.logo-text span { color: var(--accent-cyan); }

.main-nav { display: flex; align-items: center; gap: 6px; }
.main-nav a {
  padding: 8px 16px; border-radius: var(--radius-sm);
  font-size: 0.95rem; font-weight: 500; color: var(--text-light);
  transition: all var(--transition); position: relative;
}
.main-nav a:hover, .main-nav a.active {
  color: var(--secondary-orange);
  background: rgba(255, 107, 53, 0.1);
}
.main-nav a::after {
  content: ''; position: absolute; bottom: 2px; left: 50%; width: 0; height: 2px;
  background: var(--secondary-orange); transition: all var(--transition); transform: translateX(-50%);
}
.main-nav a:hover::after, .main-nav a.active::after { width: 60%; }

.mobile-toggle { display: none; cursor: pointer; padding: 8px; }
.mobile-toggle span {
  display: block; width: 24px; height: 2px; background: var(--text-light);
  margin: 5px 0; transition: var(--transition);
}

/* === Search Bar === */
.search-bar-wrap {
  background: rgba(45, 27, 105, 0.4);
  border-bottom: 1px solid rgba(0, 212, 170, 0.1);
  padding: 12px 0; margin-top: 68px;
}
.search-bar {
  display: flex; max-width: 640px; margin: 0 auto;
  background: rgba(26, 11, 46, 0.8); border-radius: 40px;
  border: 1px solid rgba(255, 107, 53, 0.25); overflow: hidden;
  transition: border-color var(--transition);
}
.search-bar:focus-within { border-color: var(--accent-cyan); }
.search-bar input {
  flex: 1; padding: 12px 24px; background: transparent; border: none;
  color: var(--text-light); font-size: 0.95rem; outline: none;
}
.search-bar input::placeholder { color: var(--text-muted); }
.search-bar button {
  padding: 12px 28px; background: var(--secondary-orange); border: none;
  color: #fff; font-size: 0.95rem; cursor: pointer; font-weight: 600;
  transition: background var(--transition);
}
.search-bar button:hover { background: #e55a28; }

/* === Hero Section === */
.hero-section {
  position: relative; overflow: hidden;
  padding: 80px 0 60px; text-align: center;
  background: linear-gradient(180deg, rgba(45, 27, 105, 0.3) 0%, transparent 100%);
}
.hero-section::before {
  content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 100%;
  background: url('../images/hero-banner.jpg') center/cover no-repeat;
  opacity: 0.25; z-index: 0;
}
.hero-content { position: relative; z-index: 1; }
.hero-content h1 {
  font-size: 3rem; margin-bottom: 16px;
  background: linear-gradient(135deg, var(--secondary-orange), var(--accent-cyan));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-content h2 {
  font-size: 1.35rem; color: var(--text-muted); font-weight: 400; margin-bottom: 28px;
}
.hero-tags { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-top: 20px; }
.hero-tags span {
  padding: 6px 18px; border-radius: 20px; font-size: 0.85rem;
  background: rgba(255, 107, 53, 0.12); border: 1px solid rgba(255, 107, 53, 0.3);
  color: var(--secondary-orange);
}
.hero-btn {
  display: inline-block; margin-top: 30px; padding: 14px 42px;
  background: linear-gradient(135deg, var(--secondary-orange), #FF8F5E);
  color: #fff; font-size: 1.1rem; font-weight: 700;
  border-radius: 40px; border: none; cursor: pointer;
  box-shadow: 0 6px 30px var(--shadow-glow);
  transition: all var(--transition);
}
.hero-btn:hover { transform: translateY(-3px); box-shadow: 0 10px 40px var(--shadow-glow); color: #fff; }

/* === Section Common === */
.section { padding: 70px 0; }
.section-title {
  text-align: center; margin-bottom: 45px;
}
.section-title h2 {
  font-size: 2rem; margin-bottom: 10px; color: var(--text-light);
}
.section-title h2 .highlight { color: var(--secondary-orange); }
.section-title p { color: var(--text-muted); font-size: 1rem; }
.section-title .divider {
  width: 60px; height: 3px; margin: 14px auto 0;
  background: linear-gradient(90deg, var(--secondary-orange), var(--accent-cyan));
  border-radius: 2px;
}

/* === Video Cards Grid === */
.video-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
}
.video-card {
  position: relative; border-radius: var(--radius-md); overflow: hidden;
  background: var(--card-bg); border: 1px solid var(--card-border);
  transition: all var(--transition); cursor: pointer;
}
.video-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 40px rgba(255, 107, 53, 0.2);
  border-color: var(--secondary-orange);
}
.video-card .thumb {
  position: relative; overflow: hidden; aspect-ratio: 3/4;
}
.video-card .thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform var(--transition); }
.video-card:hover .thumb img { transform: scale(1.06); }
.video-card .play-btn {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%) scale(0.8);
  width: 64px; height: 64px; border-radius: 50%;
  background: rgba(255, 107, 53, 0.85); display: flex; align-items: center; justify-content: center;
  opacity: 0; transition: all var(--transition);
}
.video-card:hover .play-btn { opacity: 1; transform: translate(-50%, -50%) scale(1); }
.play-btn::after {
  content: ''; width: 0; height: 0;
  border-left: 20px solid #fff; border-top: 12px solid transparent; border-bottom: 12px solid transparent;
  margin-left: 4px;
}
.video-card .card-info { padding: 16px; }
.video-card .card-title { font-size: 1rem; font-weight: 600; margin-bottom: 8px; color: var(--text-light); }
.video-card .card-meta {
  display: flex; gap: 14px; font-size: 0.8rem; color: var(--text-muted);
}
.video-card .card-meta span { display: flex; align-items: center; gap: 4px; }
.video-card .card-tags { display: flex; gap: 6px; margin-top: 8px; flex-wrap: wrap; }
.video-card .card-tags span {
  padding: 2px 10px; border-radius: 12px; font-size: 0.72rem;
  background: rgba(0, 212, 170, 0.1); color: var(--accent-cyan);
  border: 1px solid rgba(0, 212, 170, 0.2);
}

/* === Feature Modules (影视/娱乐/AI) === */
.feature-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
}
.feature-card {
  padding: 32px 24px; border-radius: var(--radius-md);
  background: var(--card-bg); border: 1px solid var(--card-border);
  text-align: center; transition: all var(--transition);
}
.feature-card:hover {
  background: var(--card-hover); border-color: var(--accent-cyan);
  transform: translateY(-4px);
}
.feature-icon {
  width: 64px; height: 64px; margin: 0 auto 18px;
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, rgba(255, 107, 53, 0.2), rgba(0, 212, 170, 0.2));
  font-size: 1.8rem;
}
.feature-card h3 { font-size: 1.15rem; margin-bottom: 10px; color: var(--text-light); }
.feature-card p { font-size: 0.9rem; color: var(--text-muted); line-height: 1.6; }

/* === Expert Section === */
.expert-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px;
}
.expert-card {
  padding: 28px 20px; border-radius: var(--radius-md);
  background: var(--card-bg); border: 1px solid var(--card-border);
  text-align: center; transition: all var(--transition);
}
.expert-card:hover { border-color: var(--accent-cyan); transform: translateY(-4px); }
.expert-avatar {
  width: 100px; height: 100px; border-radius: 50%; margin: 0 auto 16px;
  overflow: hidden; border: 3px solid rgba(255, 107, 53, 0.4);
}
.expert-avatar img { width: 100%; height: 100%; object-fit: cover; }
.expert-card h4 { font-size: 1.05rem; margin-bottom: 4px; }
.expert-card .role { font-size: 0.85rem; color: var(--secondary-orange); margin-bottom: 10px; }
.expert-card .desc { font-size: 0.82rem; color: var(--text-muted); margin-bottom: 14px; }
.expert-card .btn-group { display: flex; gap: 8px; justify-content: center; }
.btn-sm {
  padding: 6px 16px; border-radius: 20px; font-size: 0.8rem; cursor: pointer;
  border: 1px solid var(--accent-cyan); color: var(--accent-cyan);
  background: transparent; transition: all var(--transition);
}
.btn-sm:hover { background: var(--accent-cyan); color: var(--primary-dark); }
.btn-sm.orange { border-color: var(--secondary-orange); color: var(--secondary-orange); }
.btn-sm.orange:hover { background: var(--secondary-orange); color: #fff; }

/* === Partner Logo Wall === */
.partner-wall {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 30px; align-items: center;
}
.partner-item {
  padding: 18px 30px; border-radius: var(--radius-sm);
  background: rgba(45, 27, 105, 0.4); border: 1px solid rgba(255, 107, 53, 0.15);
  font-size: 1.1rem; font-weight: 600; color: var(--text-muted);
  transition: all var(--transition);
}
.partner-item:hover { border-color: var(--secondary-orange); color: var(--text-light); }

/* === FAQ Section === */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  margin-bottom: 12px; border-radius: var(--radius-sm);
  background: var(--card-bg); border: 1px solid var(--card-border);
  overflow: hidden;
}
.faq-question {
  padding: 18px 24px; cursor: pointer; display: flex;
  justify-content: space-between; align-items: center;
  font-weight: 600; font-size: 1rem; transition: background var(--transition);
}
.faq-question:hover { background: rgba(255, 107, 53, 0.08); }
.faq-question .arrow {
  width: 20px; height: 20px; transition: transform var(--transition);
  color: var(--secondary-orange); font-size: 1.2rem;
}
.faq-item.open .faq-question .arrow { transform: rotate(180deg); }
.faq-answer {
  max-height: 0; overflow: hidden; transition: max-height 0.4s ease;
  padding: 0 24px; color: var(--text-muted); font-size: 0.92rem; line-height: 1.7;
}
.faq-item.open .faq-answer { max-height: 300px; padding: 0 24px 18px; }

/* === Reviews === */
.review-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.review-card {
  padding: 24px; border-radius: var(--radius-md);
  background: var(--card-bg); border: 1px solid var(--card-border);
}
.review-header { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; }
.review-avatar {
  width: 44px; height: 44px; border-radius: 50%;
  background: linear-gradient(135deg, var(--secondary-orange), var(--accent-cyan));
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 1.1rem; color: #fff;
}
.review-name { font-weight: 600; font-size: 0.95rem; }
.review-date { font-size: 0.78rem; color: var(--text-muted); }
.review-stars { color: var(--secondary-orange); font-size: 0.9rem; margin-bottom: 8px; }
.review-text { font-size: 0.9rem; color: var(--text-muted); line-height: 1.65; }

/* === Contact Section === */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.contact-info-list { display: flex; flex-direction: column; gap: 18px; }
.contact-item {
  display: flex; align-items: flex-start; gap: 14px;
  padding: 16px; border-radius: var(--radius-sm);
  background: var(--card-bg); border: 1px solid var(--card-border);
}
.contact-icon {
  width: 42px; height: 42px; border-radius: 50%; flex-shrink: 0;
  background: rgba(255, 107, 53, 0.15); display: flex;
  align-items: center; justify-content: center; font-size: 1.2rem;
}
.contact-item h4 { font-size: 0.95rem; margin-bottom: 4px; }
.contact-item p { font-size: 0.85rem; color: var(--text-muted); }
.qrcode-wrap { display: flex; gap: 24px; justify-content: center; }
.qrcode-item { text-align: center; }
.qrcode-item img { width: 160px; height: 160px; border-radius: var(--radius-sm); margin-bottom: 8px; }
.qrcode-item p { font-size: 0.85rem; color: var(--text-muted); }

/* === How-To Guide === */
.howto-steps {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
  max-width: 900px; margin: 30px auto 0;
}
.howto-step {
  text-align: center; padding: 24px 16px;
  border-radius: var(--radius-md); background: var(--card-bg);
  border: 1px solid var(--card-border); position: relative;
}
.step-num {
  width: 40px; height: 40px; border-radius: 50%; margin: 0 auto 12px;
  background: var(--secondary-orange); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 1.1rem;
}
.howto-step h4 { font-size: 0.95rem; margin-bottom: 6px; }
.howto-step p { font-size: 0.82rem; color: var(--text-muted); }

/* === Community Section === */
.community-section {
  position: relative; overflow: hidden;
}
.community-section::before {
  content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 100%;
  background: url('../images/community-bg.jpg') center/cover no-repeat;
  opacity: 0.15; z-index: 0;
}
.community-section .container { position: relative; z-index: 1; }
.community-features {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px;
}
.comm-feat {
  padding: 24px; border-radius: var(--radius-md);
  background: rgba(26, 11, 46, 0.7); border: 1px solid rgba(0, 212, 170, 0.2);
  text-align: center; transition: all var(--transition);
}
.comm-feat:hover { border-color: var(--accent-cyan); background: rgba(0, 212, 170, 0.08); }
.comm-feat h4 { font-size: 1.05rem; margin-bottom: 8px; color: var(--accent-cyan); }
.comm-feat p { font-size: 0.88rem; color: var(--text-muted); }

/* === Social Share === */
.social-share {
  display: flex; justify-content: center; gap: 16px; margin-top: 30px;
}
.share-btn {
  padding: 10px 24px; border-radius: 24px; font-size: 0.88rem;
  border: 1px solid rgba(255, 107, 53, 0.3); color: var(--text-light);
  background: rgba(45, 27, 105, 0.5); cursor: pointer;
  transition: all var(--transition);
}
.share-btn:hover { border-color: var(--secondary-orange); background: rgba(255, 107, 53, 0.15); }

/* === Footer === */
.site-footer {
  background: rgba(17, 0, 28, 0.9); border-top: 1px solid rgba(255, 107, 53, 0.15);
  padding: 50px 0 20px;
}
.footer-grid {
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px;
  margin-bottom: 40px;
}
.footer-brand .logo-link { margin-bottom: 14px; }
.footer-brand p { font-size: 0.88rem; color: var(--text-muted); line-height: 1.6; }
.footer-col h4 {
  font-size: 1rem; margin-bottom: 16px; color: var(--secondary-orange);
  position: relative; padding-bottom: 8px;
}
.footer-col h4::after {
  content: ''; position: absolute; bottom: 0; left: 0;
  width: 30px; height: 2px; background: var(--accent-cyan);
}
.footer-col a { display: block; padding: 4px 0; font-size: 0.88rem; color: var(--text-muted); }
.footer-col a:hover { color: var(--accent-cyan); }
.footer-bottom {
  text-align: center; padding-top: 20px;
  border-top: 1px solid rgba(255, 107, 53, 0.1);
  font-size: 0.82rem; color: var(--text-muted);
}
.footer-bottom .update-time { margin-top: 6px; color: var(--accent-cyan); }

/* === Breadcrumb === */
.breadcrumb {
  padding: 14px 0; font-size: 0.85rem; color: var(--text-muted);
  margin-top: 68px;
}
.breadcrumb a { color: var(--accent-cyan); }
.breadcrumb span { margin: 0 8px; }

/* === Inner Page Content === */
.page-hero {
  padding: 50px 0 40px; text-align: center;
  background: linear-gradient(180deg, rgba(45, 27, 105, 0.4) 0%, transparent 100%);
}
.page-hero h1 { font-size: 2.4rem; margin-bottom: 12px; }
.page-hero p { color: var(--text-muted); font-size: 1.05rem; }

.content-section { padding: 50px 0; }
.content-section h2 { font-size: 1.6rem; margin-bottom: 18px; color: var(--text-light); }
.content-section h3 { font-size: 1.25rem; margin-bottom: 12px; color: var(--secondary-orange); }
.content-section p { margin-bottom: 16px; color: var(--text-muted); line-height: 1.75; }
.content-section ul { padding-left: 20px; margin-bottom: 16px; }
.content-section ul li { padding: 4px 0; color: var(--text-muted); position: relative; padding-left: 16px; }
.content-section ul li::before {
  content: ''; position: absolute; left: 0; top: 12px;
  width: 6px; height: 6px; border-radius: 50%; background: var(--accent-cyan);
}

/* === Lazy Load Placeholder === */
.lazy-img {
  background: rgba(45, 27, 105, 0.3);
  transition: opacity 0.5s ease;
}
.lazy-img[data-src] { opacity: 0.6; }

/* === Video Duration Badge === */
.video-duration {
  position: absolute; bottom: 10px; right: 10px;
  background: rgba(0,0,0,0.75); color: #fff; padding: 2px 8px;
  border-radius: 4px; font-size: 0.75rem; font-weight: 600;
  z-index: 2;
}

/* === Video Player Overlay === */
.video-player-overlay {
  display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%;
  background: rgba(0,0,0,0.85); z-index: 9999;
  align-items: center; justify-content: center;
}
.video-player-overlay.active { display: flex; }
.video-player-modal {
  width: 90%; max-width: 800px; background: var(--primary-dark);
  border-radius: var(--radius-lg); overflow: hidden;
  border: 1px solid var(--card-border); position: relative;
}
.close-player {
  position: absolute; top: 12px; right: 16px; z-index: 10;
  background: none; border: none; color: #fff; font-size: 2rem;
  cursor: pointer; line-height: 1; transition: color var(--transition);
}
.close-player:hover { color: var(--secondary-orange); }
.player-container { position: relative; }
.fake-player { position: relative; aspect-ratio: 16/9; background: #000; overflow: hidden; }
.player-poster {
  position: absolute; top: 0; left: 0; width: 100%; height: 100%;
  background-size: cover; background-position: center;
  filter: blur(2px) brightness(0.6);
}
.player-controls {
  position: absolute; bottom: 0; left: 0; width: 100%;
  background: linear-gradient(transparent, rgba(0,0,0,0.8));
  padding: 20px 16px 12px;
}
.progress-bar {
  width: 100%; height: 4px; background: rgba(255,255,255,0.2);
  border-radius: 2px; margin-bottom: 10px; cursor: pointer;
}
.progress-fill {
  width: 0; height: 100%; background: var(--secondary-orange);
  border-radius: 2px; transition: width 0.3s linear;
}
.controls-row {
  display: flex; align-items: center; gap: 12px; color: #fff; font-size: 0.85rem;
}
.ctrl-btn {
  background: none; border: none; color: #fff; font-size: 1.1rem;
  cursor: pointer; padding: 4px; transition: color var(--transition);
}
.ctrl-btn:hover { color: var(--secondary-orange); }
.time-display { font-size: 0.8rem; color: rgba(255,255,255,0.7); }
.player-title { flex: 1; text-align: center; font-weight: 600; font-size: 0.9rem; }
.player-notice {
  text-align: center; padding: 14px; font-size: 0.85rem;
  color: var(--text-muted); background: rgba(45,27,105,0.3);
}

/* === Responsive === */
@media (max-width: 1024px) {
  .video-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .expert-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .howto-steps { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .main-nav { display: none; }
  .main-nav.open {
    display: flex; flex-direction: column; position: absolute;
    top: 68px; left: 0; width: 100%; background: rgba(26, 11, 46, 0.98);
    padding: 20px; gap: 4px; border-bottom: 1px solid var(--card-border);
  }
  .main-nav.open a { padding: 12px 16px; width: 100%; }
  .mobile-toggle { display: block; }
  .hero-content h1 { font-size: 2rem; }
  .hero-content h2 { font-size: 1.1rem; }
  .video-grid { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: 1fr; }
  .expert-grid { grid-template-columns: 1fr; }
  .review-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .howto-steps { grid-template-columns: 1fr 1fr; }
  .community-features { grid-template-columns: 1fr; }
  .partner-wall { gap: 14px; }
  .partner-item { padding: 12px 20px; font-size: 0.95rem; }
  .section { padding: 45px 0; }
  .section-title h2 { font-size: 1.6rem; }
  .qrcode-wrap { flex-direction: column; align-items: center; }
}

@media (max-width: 480px) {
  .header-inner { height: 56px; }
  .logo-link img { height: 32px; }
  .logo-text { font-size: 1.1rem; }
  .search-bar-wrap { margin-top: 56px; }
  .breadcrumb { margin-top: 56px; }
  .hero-content h1 { font-size: 1.6rem; }
  .social-share { flex-wrap: wrap; }
}