/* 全局样式增强 */
.video-grid .video-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}

.video-list > div:last-child {
  border-bottom: none;
}

.detail-article {
  box-shadow: 0 2px 12px rgba(0,0,0,0.08);
}

.related-section > div > div:hover {
  transform: translateY(-3px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
  transition: all 0.3s ease;
}

/* 返回顶部按钮 */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 50px;
  height: 50px;
  background: #e74c3c;
  color: white;
  border: none;
  border-radius: 50%;
  font-size: 1.5rem;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 1000;
  box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

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

.back-to-top:hover {
  background: #c0392b;
  transform: translateY(-3px);
}

/* UI样式变体 */
.ui-style-0 { --primary-color: #e74c3c; }
.ui-style-1 { --primary-color: #3498db; }
.ui-style-2 { --primary-color: #2ecc71; }
.ui-style-3 { --primary-color: #f39c12; }
.ui-style-4 { --primary-color: #9b59b6; }
.ui-style-5 { --primary-color: #1abc9c; }
.ui-style-6 { --primary-color: #e67e22; }
.ui-style-7 { --primary-color: #34495e; }
.ui-style-8 { --primary-color: #16a085; }
.ui-style-9 { --primary-color: #27ae60; }
.ui-style-10 { --primary-color: #2980b9; }
.ui-style-11 { --primary-color: #8e44ad; }
.ui-style-12 { --primary-color: #c0392b; }
.ui-style-13 { --primary-color: #d35400; }
.ui-style-14 { --primary-color: #7f8c8d; }
.ui-style-15 { --primary-color: #2c3e50; }

/* 响应式优化 */
@media (max-width: 768px) {
  .hero-section {
    padding: 1.5rem !important;
  }

  .hero-section h1 {
    font-size: 1.5rem !important;
  }

  .hero-section p {
    font-size: 1rem !important;
  }

  .video-grid {
    grid-template-columns: 1fr !important;
    gap: 1rem !important;
  }

  .detail-article {
    padding: 1.5rem !important;
  }

  .detail-article h1 {
    font-size: 1.6rem !important;
  }

  .back-to-top {
    width: 45px;
    height: 45px;
    bottom: 1rem;
    right: 1rem;
  }
}

@media (max-width: 480px) {
  .info-section > div {
    grid-template-columns: 1fr !important;
  }
}

/* 动画效果 */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.video-card,
.video-list > div {
  animation: fadeIn 0.5s ease-out;
}

/* 链接样式增强 */
.container a {
  transition: color 0.3s ease;
}

.container a:hover {
  opacity: 0.8;
}

/* 标题装饰 */
section > h2 {
  position: relative;
  padding-left: 1rem;
}

section > h2::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 70%;
  background: currentColor;
  border-radius: 2px;
}