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

:root {
  --color-bg: #000000;
  --color-text: #ffffff;
  --color-primary: #ff0050;
  --color-secondary: #1a1a1a;
  --color-border: #333333;
  --spacing: 8px;
  --radius: 8px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
}

body.ui-style-0 {
  --color-bg: #0a0a0a;
  --color-text: #ffffff;
  --color-primary: #00d9ff;
  --color-secondary: #1a1a1a;
}

.site-header {
  background: var(--color-secondary);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: calc(var(--spacing) * 2);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: calc(var(--spacing) * 3);
}

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

.site-nav {
  display: flex;
  gap: calc(var(--spacing) * 3);
  align-items: center;
  white-space: nowrap;
}

.site-nav a {
  color: var(--color-text);
  text-decoration: none;
  padding: calc(var(--spacing) * 1) calc(var(--spacing) * 2);
  border-radius: var(--radius);
  transition: all 0.3s ease;
  font-size: 0.95rem;
}

.site-nav a:hover,
.site-nav a.active {
  background: var(--color-primary);
  color: #fff;
}

@media (max-width: 768px) {
  .header-container {
    flex-wrap: nowrap;
    padding: calc(var(--spacing) * 1.5);
  }

  .site-logo a {
    font-size: 1.2rem;
  }

  .site-nav {
    gap: calc(var(--spacing) * 1);
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  .site-nav::-webkit-scrollbar {
    display: none;
  }

  .site-nav a {
    padding: calc(var(--spacing) * 0.5) calc(var(--spacing) * 1.5);
    font-size: 0.85rem;
    flex-shrink: 0;
  }
}

.main-content {
  max-width: 1400px;
  margin: 0 auto;
  padding: calc(var(--spacing) * 3);
}

.hero-section {
  text-align: center;
  padding: calc(var(--spacing) * 6) calc(var(--spacing) * 3);
  background: linear-gradient(135deg, var(--color-secondary) 0%, var(--color-bg) 100%);
  border-radius: var(--radius);
  margin-bottom: calc(var(--spacing) * 4);
}

.hero-title {
  font-size: 2rem;
  margin-bottom: calc(var(--spacing) * 2);
  font-weight: 700;
  line-height: 1.4;
}

.hero-description {
  font-size: 1.1rem;
  opacity: 0.9;
  max-width: 800px;
  margin: 0 auto;
  line-height: 1.8;
}

@media (max-width: 768px) {
  .main-content {
    padding: calc(var(--spacing) * 2);
  }

  .hero-section {
    padding: calc(var(--spacing) * 4) calc(var(--spacing) * 2);
  }

  .hero-title {
    font-size: 1.5rem;
  }

  .hero-description {
    font-size: 1rem;
  }
}

.site-intro {
  background: var(--color-secondary);
  padding: calc(var(--spacing) * 4);
  border-radius: var(--radius);
  margin-bottom: calc(var(--spacing) * 5);
}

.site-intro h2 {
  font-size: 1.5rem;
  margin-bottom: calc(var(--spacing) * 2);
  color: var(--color-primary);
}

.site-intro p {
  font-size: 1rem;
  line-height: 1.8;
  opacity: 0.95;
}

.video-section {
  margin-bottom: calc(var(--spacing) * 6);
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: calc(var(--spacing) * 3);
}

.section-header h2 {
  font-size: 1.8rem;
  font-weight: 700;
}

.more-link {
  color: var(--color-primary);
  text-decoration: none;
  font-size: 1rem;
  transition: opacity 0.3s ease;
}

.more-link:hover {
  opacity: 0.8;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: calc(var(--spacing) * 3);
}

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

@media (max-width: 480px) {
  .video-grid {
    grid-template-columns: 1fr;
  }
}

.video-card {
  background: var(--color-secondary);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 16px rgba(0, 0, 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: var(--color-bg);
}

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

@media (max-width: 768px) {
  .video-cover {
    padding-top: 50%;
  }
}

.video-info {
  padding: calc(var(--spacing) * 2);
}

.video-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: calc(var(--spacing) * 1);
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  line-height: 1.4;
}

.video-one-line {
  font-size: 0.9rem;
  opacity: 0.8;
  margin-bottom: calc(var(--spacing) * 1);
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.video-meta {
  display: flex;
  gap: calc(var(--spacing) * 2);
  font-size: 0.85rem;
  opacity: 0.7;
}

.page-header {
  text-align: center;
  margin-bottom: calc(var(--spacing) * 5);
  padding: calc(var(--spacing) * 4) 0;
}

.page-header h1 {
  font-size: 2.5rem;
  margin-bottom: calc(var(--spacing) * 2);
}

.page-description {
  font-size: 1.1rem;
  opacity: 0.9;
  max-width: 700px;
  margin: 0 auto;
}

@media (max-width: 768px) {
  .page-header h1 {
    font-size: 1.8rem;
  }

  .page-description {
    font-size: 1rem;
  }
}

.video-player-section {
  margin-bottom: calc(var(--spacing) * 4);
}

.video-player {
  max-width: 1000px;
  margin: 0 auto;
}

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

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

.player-play-btn:hover {
  transform: translate(-50%, -50%) scale(1.1);
  box-shadow: 0 0 20px rgba(255, 0, 80, 0.5);
}

.player-play-icon {
  font-size: 2rem;
  color: #fff;
  margin-left: 4px;
}

.detail-header {
  text-align: center;
  margin-bottom: calc(var(--spacing) * 4);
}

.detail-header h1 {
  font-size: 2.2rem;
  font-weight: 700;
}

@media (max-width: 768px) {
  .detail-header h1 {
    font-size: 1.6rem;
  }
}

.detail-info,
.detail-module,
.related-videos {
  background: var(--color-secondary);
  padding: calc(var(--spacing) * 4);
  border-radius: var(--radius);
  margin-bottom: calc(var(--spacing) * 3);
}

.detail-info h2,
.detail-module h2,
.related-videos h2 {
  font-size: 1.5rem;
  margin-bottom: calc(var(--spacing) * 3);
  color: var(--color-primary);
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: calc(var(--spacing) * 2);
}

.info-item {
  padding: calc(var(--spacing) * 1.5);
  background: var(--color-bg);
  border-radius: calc(var(--radius) / 2);
}

.info-label {
  font-weight: 600;
  opacity: 0.8;
}

.detail-module p {
  font-size: 1rem;
  line-height: 1.8;
  opacity: 0.95;
}

.tags-container {
  display: flex;
  flex-wrap: wrap;
  gap: calc(var(--spacing) * 1.5);
}

.tag {
  padding: calc(var(--spacing) * 1) calc(var(--spacing) * 2);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: calc(var(--radius) / 2);
  font-size: 0.9rem;
}

.site-footer {
  background: var(--color-secondary);
  border-top: 1px solid var(--color-border);
  padding: calc(var(--spacing) * 4);
  text-align: center;
  margin-top: calc(var(--spacing) * 6);
}

.site-footer p {
  opacity: 0.7;
  font-size: 0.9rem;
}

.back-to-top {
  position: fixed;
  right: calc(var(--spacing) * 3);
  bottom: calc(var(--spacing) * 3);
  width: 50px;
  height: 50px;
  background: var(--color-primary);
  color: #fff;
  border: none;
  border-radius: 50%;
  font-size: 1.5rem;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 999;
}

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

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

@media (max-width: 768px) {
  .back-to-top {
    right: calc(var(--spacing) * 2);
    bottom: calc(var(--spacing) * 2);
    width: 45px;
    height: 45px;
    font-size: 1.2rem;
  }
}