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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  line-height: 1.6;
  background: #f5f5f5;
  color: #333;
}

body.ui-style-1 {
  --primary-color: #ff6700;
  --bg-dark: #1a1a1a;
  --bg-light: #fff;
  --text-dark: #333;
  --text-light: #666;
  background: var(--bg-dark);
  color: #fff;
}

.site-nav {
  background: var(--bg-dark);
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  gap: 2rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,0.3);
}

.nav-logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
  text-decoration: none;
}

.site-nav a {
  color: #fff;
  text-decoration: none;
  font-size: 1rem;
  transition: color 0.3s;
}

.site-nav a:hover {
  color: var(--primary-color);
}

@media (max-width: 768px) {
  .site-nav {
    padding: 0.75rem 1rem;
    gap: 1rem;
    flex-wrap: nowrap;
    overflow-x: auto;
    white-space: nowrap;
  }

  .nav-logo {
    font-size: 1.2rem;
  }

  .site-nav a {
    font-size: 0.9rem;
    flex-shrink: 0;
  }
}

.site-footer {
  background: var(--bg-dark);
  color: #999;
  text-align: center;
  padding: 2rem;
  margin-top: 3rem;
}

main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 2rem;
}

h1 {
  font-size: 2rem;
  margin-bottom: 1.5rem;
  color: #fff;
}

.intro-section {
  background: rgba(255, 255, 255, 0.05);
  padding: 2rem;
  border-radius: 12px;
  margin-bottom: 3rem;
  line-height: 1.8;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

@media (max-width: 768px) {
  .video-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }
}

.video-card {
  background: rgba(255, 255, 255, 0.08);
  border-radius: 12px;
  overflow: hidden;
  transition: transform 0.3s, box-shadow 0.3s;
  position: relative;
}

.video-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 12px 24px rgba(255, 103, 0, 0.3);
}

.video-card__link {
  text-decoration: none;
  color: inherit;
  display: block;
}

.video-cover {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  overflow: hidden;
  background: #000;
}

.video-cover img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.video-info {
  padding: 1rem;
}

.video-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: #fff;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.video-one-line {
  font-size: 0.85rem;
  color: #aaa;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.video-meta {
  font-size: 0.8rem;
  color: #888;
  margin-top: 0.5rem;
}

.video-section {
  margin-bottom: 3rem;
}

.section-title {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  color: #fff;
  border-left: 4px solid var(--primary-color);
  padding-left: 1rem;
}

.video-player-section {
  margin-bottom: 2rem;
}

.video-player {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
}

.video-player-inner {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  background: #000;
  border-radius: 12px;
  overflow: hidden;
}

.player-play-btn {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 80px;
  height: 80px;
  background: rgba(255, 103, 0, 0.9);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  transition: all 0.3s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.player-play-btn:hover {
  background: var(--primary-color);
  transform: translate(-50%, -50%) scale(1.1);
}

.player-play-icon {
  font-size: 2rem;
  color: #fff;
  margin-left: 5px;
}

.detail-main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

.detail-header h1 {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
}

.info-block, .content-module {
  background: rgba(255, 255, 255, 0.05);
  padding: 2rem;
  border-radius: 12px;
  margin-bottom: 2rem;
  line-height: 1.8;
}

.info-block h2, .content-module h2 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
  color: var(--primary-color);
}

.info-item {
  margin-bottom: 0.8rem;
  font-size: 1rem;
}

.info-item strong {
  color: #fff;
  display: inline-block;
  min-width: 80px;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 1.5rem;
}

.video-card--related {
  background: rgba(255, 255, 255, 0.05);
}

.page-header {
  margin-bottom: 2rem;
}

.page-header h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.page-desc {
  font-size: 1.1rem;
  color: #aaa;
  line-height: 1.8;
  background: rgba(255, 255, 255, 0.05);
  padding: 1.5rem;
  border-radius: 8px;
}

.page--grid .video-grid, .page--with-sidebar .video-grid, .page--grouped .group__grid {
  margin-top: 2rem;
}

.page--top .top-list__items {
  list-style: none;
  counter-reset: top-counter;
}

.page--top .top-list__item {
  counter-increment: top-counter;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 12px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  position: relative;
}

.page--top .top-list__item::before {
  content: counter(top-counter);
  position: absolute;
  left: -10px;
  top: -10px;
  width: 40px;
  height: 40px;
  background: var(--primary-color);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: 700;
}

.page--top .top-list__item:nth-child(1)::before { background: #ffd700; color: #000; }
.page--top .top-list__item:nth-child(2)::before { background: #c0c0c0; color: #000; }
.page--top .top-list__item:nth-child(3)::before { background: #cd7f32; color: #000; }

.top-list__cover {
  flex-shrink: 0;
  width: 150px;
  height: 84px;
  border-radius: 8px;
  overflow: hidden;
}

.top-list__cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.top-list__info {
  flex: 1;
}

.top-list__title {
  font-size: 1.3rem;
  margin-bottom: 0.5rem;
  color: #fff;
}

.top-list__desc {
  font-size: 0.95rem;
  color: #aaa;
  line-height: 1.5;
}

.page--grouped .group {
  margin-bottom: 3rem;
}

.page--grouped .group__title {
  font-size: 1.8rem;
  margin-bottom: 1.5rem;
  color: var(--primary-color);
  border-bottom: 2px solid var(--primary-color);
  padding-bottom: 0.5rem;
}

@media (max-width: 768px) {
  main, .detail-main {
    padding: 1rem;
  }

  h1, .detail-header h1 {
    font-size: 1.8rem;
  }

  .video-card__link {
    display: flex;
    flex-direction: column;
  }

  .video-cover {
    padding-top: 45%;
  }

  .video-title {
    font-size: 0.95rem;
  }

  .video-one-line {
    font-size: 0.8rem;
  }

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

  .page--top .top-list__item {
    flex-direction: column;
    align-items: flex-start;
  }

  .top-list__cover {
    width: 100%;
    height: auto;
    padding-top: 56.25%;
    position: relative;
  }

  .top-list__cover img {
    position: absolute;
    top: 0;
    left: 0;
  }
}

.back-to-top {
  position: fixed;
  right: 2rem;
  bottom: 2rem;
  width: 50px;
  height: 50px;
  background: var(--primary-color);
  color: #fff;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: none;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  z-index: 99;
  transition: all 0.3s;
}

.back-to-top.show {
  display: flex;
}

.back-to-top:hover {
  transform: translateY(-5px);
  box-shadow: 0 4px 12px rgba(255, 103, 0, 0.5);
}