/* 全站样式 - UI Style 7 - Layout C */

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

.video-card {
  background: white;
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
  transition: transform 0.3s, box-shadow 0.3s;
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.video-card h3 {
  font-size: 1.125rem;
  margin-bottom: 0.5rem;
  color: #1f2937;
}

.video-card h3 a {
  color: inherit;
  transition: color 0.3s;
}

.video-card h3 a:hover {
  color: #667eea;
}

.video-card .meta {
  color: #6b7280;
  font-size: 0.875rem;
  margin-bottom: 0.75rem;
}

.video-card .one-line {
  color: #4b5563;
  line-height: 1.6;
  margin-bottom: 0.75rem;
}

.video-card .tags {
  color: #9ca3af;
  font-size: 0.875rem;
}

.video-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.video-item {
  background: white;
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
  transition: box-shadow 0.3s;
}

.video-item:hover {
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

/* 响应式调整 */
@media (max-width: 768px) {
  .video-grid {
    grid-template-columns: 1fr;
  }

  .container {
    padding: 0 0.75rem;
  }

  main.container {
    padding: 1rem 0.75rem !important;
  }

  .video-card, .video-item {
    padding: 1rem;
  }

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

  h2 {
    font-size: 1.25rem !important;
  }
}

/* 返回顶部按钮 */
#backToTop {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: #667eea;
  color: white;
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  display: none;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
  transition: all 0.3s;
  z-index: 1000;
}

#backToTop:hover {
  background: #5568d3;
  transform: translateY(-4px);
}

#backToTop.show {
  display: flex;
}