body.ui-style-7 {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Microsoft YaHei", sans-serif;
  background: linear-gradient(to bottom, #f5f7fa 0%, #e8ecf1 100%);
}

.video-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 20px rgba(0,0,0,0.15);
}

.video-grid .video-card {
  transition: all 0.3s ease;
}

main section {
  animation: fadeInUp 0.6s ease;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

nav a {
  position: relative;
  overflow: hidden;
}

nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: white;
  transition: all 0.3s;
  transform: translateX(-50%);
}

nav a:hover::after {
  width: 80%;
}

.video-card {
  position: relative;
  overflow: hidden;
}

.video-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
  transition: left 0.5s;
}

.video-card:hover::before {
  left: 100%;
}

a {
  transition: color 0.3s ease;
}

a:hover {
  color: #3498db;
}

button, .btn {
  cursor: pointer;
  transition: all 0.3s ease;
}

button:hover, .btn:hover {
  transform: scale(1.05);
}

.hero h1 {
  background: linear-gradient(135deg, #2c3e50 0%, #3498db 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

  .rank-topic-section {
    grid-template-columns: 1fr !important;
  }

  main section {
    padding: 20px !important;
  }

  h1 {
    font-size: 24px !important;
  }

  h2 {
    font-size: 20px !important;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 15px;
  }

  nav a {
    padding: 6px 4px;
    font-size: 12px;
  }
}

.list-content > div > div {
  transition: all 0.3s ease;
}

.list-content > div > div:hover {
  background: #f8f9fa;
  transform: translateX(5px);
}

.ranked-list > div:nth-child(1) {
  background: linear-gradient(135deg, #fff5f5 0%, #ffe8e8 100%);
}

.ranked-list > div:nth-child(2) {
  background: linear-gradient(135deg, #fff8f0 0%, #ffe8d0 100%);
}

.ranked-list > div:nth-child(3) {
  background: linear-gradient(135deg, #fffef0 0%, #fff8d0 100%);
}

footer {
  border-top: 4px solid #3498db;
}

::selection {
  background: #3498db;
  color: white;
}

::-webkit-scrollbar {
  width: 10px;
}

::-webkit-scrollbar-track {
  background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
  background: #888;
  border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
  background: #555;
}