:root {
  --primary: #4f46e5;
  --primary-light: #c7d2fe;
  --secondary: #6b7280;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --light: #f3f4f6;
  --dark: #1f2937;
  --card-shadow: 0 10px 15px -3px rgba(0,0,0,.08), 0 4px 6px -4px rgba(0,0,0,.05);
  --card-hover: 0 20px 25px -5px rgba(0,0,0,.1), 0 8px 10px -6px rgba(0,0,0,.05);
}

body {
  font-family: "Inter", system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial;
  background-color: #fafafa;
  color: #111827;
  line-height: 1.5;
}

/* 顶部导航栏 */
.navbar {
  background-color: rgba(255,255,255,.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(0,0,0,.06);
  box-shadow: 0 1px 3px rgba(0,0,0,.05);
}

/* Logo */
.navbar-brand img {
  height: 36px;
}

/* 搜索框 */
.search-wrap {
  max-width: 720px;
  margin: 0 auto;
}

.search-input {
  height: 52px;
  padding: 0 16px;
  font-size: 16px;
  border-radius: 12px;
  border: 2px solid rgba(0,0,0,.08);
  box-shadow: 0 4px 6px -1px rgba(0,0,0,.06);
  transition: all .2s ease;
}

.search-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(79, 70, 229, .12);
  outline: none;
}

.search-btn {
  height: 52px;
  border-radius: 12px;
  background-color: var(--primary);
  border: 0;
  padding: 0 20px;
  color: #fff;
  font-weight: 600;
  transition: all .2s ease;
}

.search-btn:hover {
  background-color: #4338ca;
  transform: translateY(-1px);
}

/* 分类筛选 */
.categories {
  padding: 16px 0;
  overflow-x: auto;
  scrollbar-width: thin;
}

.categories::-webkit-scrollbar {
  height: 4px;
}

.categories::-webkit-scrollbar-thumb {
  background-color: rgba(0,0,0,.2);
  border-radius: 4px;
}

.category-item {
  display: inline-flex;
  align-items: center;
  padding: 8px 16px;
  margin-right: 10px;
  margin-bottom: 8px;
  border-radius: 999px;
  background-color: rgba(255,255,255,.85);
  border: 1px solid rgba(0,0,0,.06);
  color: #111827;
  font-weight: 500;
  font-size: 14px;
  white-space: nowrap;
  cursor: pointer;
  transition: all .2s ease;
}

.category-item:hover {
  background-color: #fff;
  border-color: rgba(0,0,0,.1);
  transform: translateY(-1px);
}

.category-item.active {
  background-color: var(--primary);
  color: #fff;
  border-color: rgba(0,0,0,.1);
}

/* 工具卡片 */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.tool-card {
  background-color: rgba(255,255,255,.9);
  border: 1px solid rgba(0,0,0,.06);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--card-shadow);
  transition: all .25s ease;
  height: 100%;
  display: flex;
  flex-direction: column;
}

.tool-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--card-hover);
}

.tool-card-header {
  padding: 16px;
  border-bottom: 1px solid rgba(0,0,0,.04);
  flex-shrink: 0;
}

.tool-card-body {
  padding: 16px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.tool-card-footer {
  padding: 12px 16px;
  border-top: 1px solid rgba(0,0,0,.04);
  flex-shrink: 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.tool-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 6px;
  line-height: 1.3;
}

.tool-brief {
  color: #4b5563;
  font-size: 14px;
  margin-bottom: 12px;
  flex: 1;
}

.tool-meta {
  display: flex;
  align-items: center;
  font-size: 12px;
  color: #6b7280;
}

.tool-meta-item {
  display: flex;
  align-items: center;
  margin-right: 12px;
}

.tool-meta-item i {
  margin-right: 4px;
}

.tool-tag {
  display: inline-block;
  padding: 4px 8px;
  margin-right: 6px;
  margin-bottom: 6px;
  border-radius: 6px;
  background-color: rgba(79, 70, 229, .1);
  color: #4f46e5;
  font-size: 12px;
  font-weight: 500;
}

/* 推荐区标题 */
.section-title {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
}

.section-title::after {
  content: "";
  flex: 1;
  height: 1px;
  background-color: rgba(0,0,0,.1);
  margin-left: 12px;
}

/* 页脚 */
.footer {
  margin-top: 60px;
  padding: 32px 0;
  background-color: rgba(255,255,255,.95);
  border-top: 1px solid rgba(0,0,0,.06);
  font-size: 14px;
  color: #6b7280;
}

/* 响应式 */
@media (max-width: 768px) {
  .tools-grid {
    grid-template-columns: repeat(auto-fill, minmax(100%, 1fr));
  }
  .search-wrap {
    padding: 0 12px;
  }
  .section-title {
    font-size: 18px;
  }
}