/* 基础重置与变量定义 */
:root {
  --color-primary: #2563EB;
  --color-primary-hover: #1D4ED8;
  --color-text: #333333;
  --color-text-light: #6B7280;
  --color-bg: #FFFFFF;
  --color-bg-secondary: #F3F4F6;
  --color-border: #E5E7EB;
  --color-shadow: rgba(0, 0, 0, 0.1);
  --border-radius: 8px;
  --transition: all 0.2s ease;
}

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

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* 头部样式 */
.header {
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  padding: 20px 0;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
}

.title {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--color-text);
  text-align: center;
}

.search-container {
  position: relative;
  max-width: 500px;
  margin: 0 auto;
}

.search-input {
  width: 100%;
  padding: 12px 16px;
  padding-right: 40px;
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  font-size: 1rem;
  background-color: var(--color-bg);
  transition: var(--transition);
}

.search-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.search-clear {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  font-size: 1.2rem;
  color: var(--color-text-light);
  cursor: pointer;
  padding: 0;
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: var(--transition);
}

.search-clear:hover {
  background-color: var(--color-bg-secondary);
  color: var(--color-text);
}

/* 分类导航 */
.category-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 30px 0 20px;
  justify-content: center;
}

.category-btn {
  padding: 8px 16px;
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  color: var(--color-text-light);
  font-size: 0.875rem;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.category-btn:hover,
.category-btn.active {
  background-color: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

/* 链接容器 */
.links-container {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
  margin-bottom: 40px;
}

/* 链接卡片 */
.link-card {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: 20px;
  transition: var(--transition);
  text-decoration: none;
  color: inherit;
  display: block;
  position: relative;
  overflow: hidden;
}

.link-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, transparent 0%, rgba(37, 99, 235, 0.05) 100%);
  opacity: 0;
  transition: var(--transition);
}

.link-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px var(--color-shadow);
  border-color: var(--color-primary);
}

.link-card:hover::before {
  opacity: 1;
}

.link-header {
  display: flex;
  align-items: center;
  margin-bottom: 12px;
  gap: 12px;
}

.link-icon {
  width: 32px;
  height: 32px;
  border-radius: 6px;
  object-fit: cover;
  flex-shrink: 0;
  background-color: var(--color-bg-secondary);
  padding: 4px;
}

.link-name {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-text);
  margin: 0;
}

.link-description {
  color: var(--color-text-light);
  font-size: 0.875rem;
  margin-bottom: 12px;
  line-height: 1.5;
}

.link-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 8px;
}

.link-tag {
  background-color: var(--color-bg-secondary);
  color: var(--color-text-light);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.75rem;
  line-height: 1.4;
}

/* 空状态 */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--color-text-light);
}

.empty-state p {
  font-size: 1.1rem;
}

/* 加载状态 */
.loading {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(255, 255, 255, 0.9);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--color-bg-secondary);
  border-top: 3px solid var(--color-primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-bottom: 16px;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* 响应式设计 */
@media (max-width: 768px) {
  .container {
    padding: 0 16px;
  }
  
  .title {
    font-size: 1.5rem;
  }
  
  .links-container {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  .link-card {
    padding: 16px;
  }
  
  .category-nav {
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: 8px;
    margin: 20px 0 16px;
  }
  
  .category-btn {
    flex-shrink: 0;
  }
}

@media (max-width: 480px) {
  .search-container {
    max-width: 100%;
  }
  
  .link-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
  
  .link-icon {
    margin-bottom: 4px;
  }
}

/* 可访问性增强 */
.search-input:focus-visible,
.category-btn:focus-visible,
.link-card:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* 减少动画（针对偏好减少动画的用户） */
@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
    animation: none !important;
  }
}