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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  color: #1a1a1a;
  background: #fff;
}

body.ui-style-1 {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: #000;
  color: #fff;
}

.layout {
  display: flex;
  min-height: 100vh;
}

.layout__side {
  width: 260px;
  background: #f8f8f8;
  padding: 24px;
  border-right: 1px solid #e5e5e5;
}

body.ui-style-1 .layout__side {
  background: #1a1a1a;
  border-right-color: #333;
}

.layout__main {
  flex: 1;
  padding: 24px;
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
}

.site-logo {
  font-size: 24px;
  font-weight: 700;
  color: #ff6700;
  text-decoration: none;
  display: block;
  margin-bottom: 32px;
}

body.ui-style-1 .site-logo {
  color: #fff;
}

.side-nav {
  list-style: none;
}

.side-nav__item {
  margin-bottom: 8px;
}

.side-nav__link {
  display: block;
  padding: 12px 16px;
  color: #333;
  text-decoration: none;
  border-radius: 8px;
  transition: all 0.3s;
}

body.ui-style-1 .side-nav__link {
  color: #e5e5e5;
}

.side-nav__link:hover,
.side-nav__link.active {
  background: #ff6700;
  color: #fff;
}

body.ui-style-1 .side-nav__link:hover,
body.ui-style-1 .side-nav__link.active {
  background: #ff4400;
}

.site-intro {
  padding: 32px;
  background: #f8f8f8;
  border-radius: 12px;
  margin-bottom: 32px;
}

body.ui-style-1 .site-intro {
  background: #1a1a1a;
  border: 1px solid #333;
}

.site-intro__title {
  font-size: 28px;
  margin-bottom: 16px;
  color: #1a1a1a;
}

body.ui-style-1 .site-intro__title {
  color: #fff;
}

.site-intro__text {
  font-size: 15px;
  line-height: 1.8;
  color: #666;
}

body.ui-style-1 .site-intro__text {
  color: #999;
}

.filter-bar {
  display: flex;
  gap: 16px;
  padding: 20px;
  background: #f8f8f8;
  border-radius: 8px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

body.ui-style-1 .filter-bar {
  background: #1a1a1a;
  border: 1px solid #333;
}

.filter-tag {
  padding: 8px 16px;
  background: #fff;
  border: 1px solid #ddd;
  border-radius: 20px;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.3s;
}

body.ui-style-1 .filter-tag {
  background: #2a2a2a;
  border-color: #444;
  color: #e5e5e5;
}

.filter-tag:hover {
  background: #ff6700;
  border-color: #ff6700;
  color: #fff;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 24px;
  margin-bottom: 32px;
}

.video-card {
  background: #fff;
  border-radius: 12px;
  overflow: hidden;
  transition: transform 0.3s, box-shadow 0.3s;
  border: 1px solid #e5e5e5;
}

body.ui-style-1 .video-card {
  background: #1a1a1a;
  border-color: #333;
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.1);
}

body.ui-style-1 .video-card:hover {
  box-shadow: 0 8px 24px rgba(255,255,255,0.1);
}

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

.video-cover {
  position: relative;
  padding-top: 140%;
  overflow: hidden;
  background: #f0f0f0;
}

body.ui-style-1 .video-cover {
  background: #2a2a2a;
}

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

.video-info {
  padding: 16px;
}

.video-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  color: #1a1a1a;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

body.ui-style-1 .video-title {
  color: #fff;
}

.video-one-line {
  font-size: 13px;
  color: #666;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

body.ui-style-1 .video-one-line {
  color: #999;
}

.module-section {
  margin-bottom: 48px;
}

.module-section__title {
  font-size: 24px;
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 2px solid #ff6700;
  color: #1a1a1a;
}

body.ui-style-1 .module-section__title {
  color: #fff;
  border-bottom-color: #ff4400;
}

.page-header {
  margin-bottom: 32px;
}

.page-header__title {
  font-size: 32px;
  margin-bottom: 16px;
  color: #1a1a1a;
}

body.ui-style-1 .page-header__title {
  color: #fff;
}

.page-header__desc {
  font-size: 15px;
  color: #666;
  line-height: 1.8;
}

body.ui-style-1 .page-header__desc {
  color: #999;
}

.video-player-section {
  margin-bottom: 32px;
}

.video-player {
  background: #000;
  border-radius: 12px;
  overflow: hidden;
}

.video-player-inner {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  background: #000;
}

.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;
}

.player-play-btn:hover {
  background: rgba(255, 103, 0, 1);
  transform: translate(-50%, -50%) scale(1.1);
}

.player-play-icon {
  color: #fff;
  font-size: 32px;
}

.detail-header {
  margin-bottom: 32px;
}

.detail-title {
  font-size: 36px;
  margin-bottom: 24px;
  color: #1a1a1a;
}

body.ui-style-1 .detail-title {
  color: #fff;
}

.detail-info {
  background: #f8f8f8;
  padding: 24px;
  border-radius: 12px;
  margin-bottom: 32px;
}

body.ui-style-1 .detail-info {
  background: #1a1a1a;
  border: 1px solid #333;
}

.detail-info__title {
  font-size: 20px;
  margin-bottom: 16px;
  color: #1a1a1a;
}

body.ui-style-1 .detail-info__title {
  color: #fff;
}

.info-item {
  display: flex;
  padding: 8px 0;
  border-bottom: 1px solid #e5e5e5;
}

body.ui-style-1 .info-item {
  border-bottom-color: #333;
}

.info-item__label {
  width: 100px;
  font-weight: 600;
  color: #666;
}

body.ui-style-1 .info-item__label {
  color: #999;
}

.info-item__value {
  flex: 1;
  color: #1a1a1a;
}

body.ui-style-1 .info-item__value {
  color: #e5e5e5;
}

.content-module {
  background: #fff;
  padding: 24px;
  border-radius: 12px;
  margin-bottom: 24px;
  border: 1px solid #e5e5e5;
}

body.ui-style-1 .content-module {
  background: #1a1a1a;
  border-color: #333;
}

.content-module__title {
  font-size: 22px;
  margin-bottom: 16px;
  color: #1a1a1a;
}

body.ui-style-1 .content-module__title {
  color: #fff;
}

.content-module__text {
  font-size: 15px;
  line-height: 1.8;
  color: #333;
}

body.ui-style-1 .content-module__text {
  color: #ccc;
}

.related-section {
  margin-top: 48px;
}

.related-section__title {
  font-size: 24px;
  margin-bottom: 24px;
  color: #1a1a1a;
}

body.ui-style-1 .related-section__title {
  color: #fff;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 20px;
}

.video-card--related {
  background: #f8f8f8;
}

body.ui-style-1 .video-card--related {
  background: #2a2a2a;
}

.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 50px;
  height: 50px;
  background: #ff6700;
  color: #fff;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s;
  font-size: 20px;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: #ff4400;
  transform: translateY(-4px);
}

.pagination {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 32px;
}

.pagination__btn {
  padding: 8px 16px;
  background: #f8f8f8;
  border: 1px solid #ddd;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.3s;
}

body.ui-style-1 .pagination__btn {
  background: #2a2a2a;
  border-color: #444;
  color: #e5e5e5;
}

.pagination__btn:hover,
.pagination__btn.active {
  background: #ff6700;
  border-color: #ff6700;
  color: #fff;
}

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

.top-list__item {
  display: flex;
  align-items: center;
  padding: 16px;
  background: #f8f8f8;
  border-radius: 8px;
  margin-bottom: 12px;
  counter-increment: rank;
  position: relative;
}

body.ui-style-1 .top-list__item {
  background: #1a1a1a;
  border: 1px solid #333;
}

.top-list__item::before {
  content: counter(rank);
  font-size: 24px;
  font-weight: 700;
  color: #ff6700;
  margin-right: 16px;
  min-width: 40px;
  text-align: center;
}

.top-list__cover {
  width: 80px;
  height: 112px;
  border-radius: 6px;
  overflow: hidden;
  margin-right: 16px;
}

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

.top-list__info {
  flex: 1;
}

.top-list__title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  color: #1a1a1a;
}

body.ui-style-1 .top-list__title {
  color: #fff;
}

.top-list__desc {
  font-size: 14px;
  color: #666;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

body.ui-style-1 .top-list__desc {
  color: #999;
}

.group {
  margin-bottom: 48px;
}

.group__title {
  font-size: 22px;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid #ddd;
  color: #1a1a1a;
}

body.ui-style-1 .group__title {
  color: #fff;
  border-bottom-color: #444;
}

.group__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 20px;
}

@media (max-width: 768px) {
  .layout {
    flex-direction: column;
  }

  .layout__side {
    width: 100%;
    border-right: none;
    border-bottom: 1px solid #e5e5e5;
  }

  body.ui-style-1 .layout__side {
    border-bottom-color: #333;
  }

  .side-nav {
    display: flex;
    gap: 8px;
    overflow-x: auto;
  }

  .side-nav__item {
    margin-bottom: 0;
  }

  .side-nav__link {
    white-space: nowrap;
    padding: 8px 16px;
  }

  .video-grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 16px;
  }

  .video-cover {
    padding-top: 120%;
  }

  .related-grid {
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 12px;
  }

  .filter-bar {
    gap: 8px;
    padding: 12px;
  }

  .module-section__title {
    font-size: 20px;
  }

  .detail-title {
    font-size: 28px;
  }

  .top-list__item {
    flex-wrap: wrap;
  }

  .top-list__item::before {
    position: absolute;
    top: 16px;
    left: 16px;
    font-size: 20px;
    min-width: 30px;
  }

  .top-list__cover {
    margin-left: 50px;
  }

  .layout__main {
    padding: 16px;
  }
}