/* ===== CSS 自定义属性 (CSS Variables) ===== */
:root {
  /* 主色调 */
  --primary-color: #5B6AFF;
  --secondary-color: #8C54FF;
  --accent-color: #667EEA;
  
  /* 背景色 */
  --bg-primary: #FFFFFF;
  --bg-secondary: #F5F7FA;
  --bg-card: #FFFFFF;
  --bg-hover: #F8F9FF;
  
  /* 文字颜色 */
  --text-primary: #333333;
  --text-secondary: #666666;
  --text-muted: #999999;
  --text-inverse: #FFFFFF;
  
  /* 边框颜色 */
  --border-color: #E5E7EB;
  --border-hover: #D1D5DB;
  
  /* 阴影 */
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
  --shadow-hover: 0 8px 32px rgba(91,106,255,0.15);
  
  /* 间距 */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  
  /* 圆角 */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  
  /* 布局尺寸 */
  --header-height: 60px;
  --sidebar-width: 240px;
  --sidebar-collapsed-width: 60px;
  
  /* 动画 */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* 暗色主题 */
[data-theme="dark"] {
  --bg-primary: #0F172A;
  --bg-secondary: #1E293B;
  --bg-card: #1E293B;
  --bg-hover: #334155;
  
  --text-primary: #F1F5F9;
  --text-secondary: #CBD5E1;
  --text-muted: #94A3B8;
  
  --border-color: #334155;
  --border-hover: #475569;
  
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.4);
}

/* ===== 基础重置和全局样式 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* 滚动条样式 */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--border-hover);
}

/* ===== 顶部导航栏 ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background-color: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  backdrop-filter: blur(10px);
  z-index: 1000;
  transition: all var(--transition-normal);
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.header-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  flex-shrink: 0;
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
}

.site-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
}

/* ===== 搜索框 ===== */
.search-container {
  position: relative;
  flex: 1;
  max-width: 500px;
  margin: 0 var(--spacing-xl);
}

.search-box {
  position: relative;
  display: flex;
  align-items: center;
}

.search-box input {
  width: 100%;
  height: 40px;
  padding: 0 var(--spacing-md) 0 44px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 0.875rem;
  transition: all var(--transition-fast);
}

.search-box input:focus {
  outline: none;
  border-color: var(--primary-color);
  background-color: var(--bg-card);
  box-shadow: 0 0 0 3px rgba(91,106,255,0.1);
}

.search-icon {
  position: absolute;
  left: var(--spacing-md);
  color: var(--text-muted);
  pointer-events: none;
}

.search-clear {
  position: absolute;
  right: var(--spacing-md);
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: var(--spacing-xs);
  border-radius: var(--radius-sm);
  opacity: 0;
  transition: all var(--transition-fast);
}

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

.search-box:focus-within .search-clear,
.search-box.has-content .search-clear {
  opacity: 1;
}

/* ===== 头部操作区 ===== */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  flex-shrink: 0;
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: none;
  border-radius: var(--radius-md);
  background-color: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.theme-toggle:hover {
  background-color: var(--bg-hover);
  color: var(--text-primary);
}

.theme-icon-dark {
  display: none;
}

[data-theme="dark"] .theme-icon-light {
  display: none;
}

[data-theme="dark"] .theme-icon-dark {
  display: block;
}

.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: none;
  background: none;
  cursor: pointer;
  padding: var(--spacing-sm);
}

.mobile-menu-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--text-primary);
  margin: 2px 0;
  transition: all var(--transition-fast);
}

/* ===== 主要布局 ===== */
.main {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  min-height: 100vh;
  padding-top: var(--header-height);
  transition: grid-template-columns var(--transition-normal);
}

.main.sidebar-collapsed {
  grid-template-columns: var(--sidebar-collapsed-width) 1fr;
}

/* ===== 侧边栏 ===== */
.sidebar {
  background-color: var(--bg-card);
  border-right: 1px solid var(--border-color);
  overflow-y: auto;
  transition: all var(--transition-normal);
}

.category-nav {
  padding: var(--spacing-lg);
}

.category-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-lg);
}

.category-header h2 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
}

.sidebar-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border: none;
  background: none;
  color: var(--text-muted);
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.sidebar-toggle:hover {
  background-color: var(--bg-hover);
  color: var(--text-secondary);
}

.category-list {
  list-style: none;
}

.category-item {
  margin-bottom: var(--spacing-xs);
}

.category-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  text-decoration: none;
  transition: all var(--transition-fast);
}

.category-link:hover {
  background-color: var(--bg-hover);
  color: var(--text-primary);
}

.category-item.active .category-link {
  background-color: var(--primary-color);
  color: var(--text-inverse);
}

.category-icon {
  flex-shrink: 0;
}

.category-name {
  flex: 1;
  font-size: 0.875rem;
  font-weight: 500;
}

.category-count {
  font-size: 0.75rem;
  padding: 2px 6px;
  background-color: rgba(255,255,255,0.2);
  border-radius: var(--radius-full);
  min-width: 20px;
  text-align: center;
}

.category-item.active .category-count {
  background-color: rgba(255,255,255,0.2);
}

.category-item:not(.active) .category-count {
  background-color: var(--bg-secondary);
  color: var(--text-muted);
}

/* ===== 主内容区 ===== */
.content {
  padding: var(--spacing-xl);
  background-color: var(--bg-secondary);
  min-height: calc(100vh - var(--header-height));
}

.content-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: var(--spacing-xl);
  gap: var(--spacing-lg);
}

.content-title h2 {
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-xs);
}

.content-subtitle {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

.content-filters {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.filter-group {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.filter-group label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  white-space: nowrap;
}

.sort-select {
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background-color: var(--bg-card);
  color: var(--text-primary);
  font-size: 0.875rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.sort-select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(91,106,255,0.1);
}

.view-toggle {
  display: flex;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.view-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: none;
  background-color: var(--bg-card);
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.view-btn:hover {
  background-color: var(--bg-hover);
  color: var(--text-secondary);
}

.view-btn.active {
  background-color: var(--primary-color);
  color: var(--text-inverse);
}

/* ===== 工具网格 ===== */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-2xl);
}

.tools-grid.list-view {
  grid-template-columns: 1fr;
}

.tools-grid.list-view .tool-card {
  display: flex;
  align-items: center;
  padding: var(--spacing-lg);
}

.tools-grid.list-view .card-icon {
  margin-right: var(--spacing-lg);
  margin-bottom: 0;
}

.tools-grid.list-view .card-content {
  flex: 1;
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.tools-grid.list-view .card-info {
  flex: 1;
}

.tools-grid.list-view .card-title {
  margin-bottom: var(--spacing-xs);
}

.tools-grid.list-view .card-description {
  margin-bottom: var(--spacing-sm);
}

/* ===== 工具卡片 ===== */
.tool-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  transition: all var(--transition-normal);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.tool-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-normal);
}

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

.tool-card:hover::before {
  transform: scaleX(1);
}

.card-icon {
  width: 48px;
  height: 48px;
  margin-bottom: var(--spacing-md);
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-inverse);
  font-size: 1.5rem;
  font-weight: 600;
}

.card-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
  line-height: 1.4;
}

.card-description {
  color: var(--text-secondary);
  font-size: 0.875rem;
  line-height: 1.5;
  margin-bottom: var(--spacing-md);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-md);
}

.card-tag {
  padding: 2px var(--spacing-sm);
  background-color: var(--bg-secondary);
  color: var(--text-muted);
  font-size: 0.75rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

.card-action {
  width: 100%;
  padding: var(--spacing-md);
  border: none;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: var(--text-inverse);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.card-action:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(91,106,255,0.3);
}

/* 原创工具标识 */
.original-badge {
  display: inline-block;
  background: linear-gradient(135deg, #FF6B6B, #FF8E53);
  color: white;
  font-size: 0.625rem;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: var(--radius-full);
  margin-left: var(--spacing-xs);
  vertical-align: top;
  box-shadow: 0 2px 4px rgba(255,107,107,0.3);
}

/* ===== 状态组件 ===== */
.loading-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2xl);
  color: var(--text-secondary);
}

.loading-spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border-color);
  border-top: 3px solid var(--primary-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-bottom: var(--spacing-md);
}

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

.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2xl);
  text-align: center;
  color: var(--text-secondary);
}

.empty-icon {
  margin-bottom: var(--spacing-lg);
  color: var(--text-muted);
}

.empty-state h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
}

.empty-state p {
  font-size: 0.875rem;
  max-width: 300px;
}

/* ===== 返回顶部按钮 ===== */
.back-to-top {
  position: fixed;
  bottom: var(--spacing-xl);
  right: var(--spacing-xl);
  width: 48px;
  height: 48px;
  border: none;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: var(--text-inverse);
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  transform: translateY(100px);
  opacity: 0;
  transition: all var(--transition-normal);
  z-index: 999;
}

.back-to-top.visible {
  transform: translateY(0);
  opacity: 1;
}

.back-to-top:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(91,106,255,0.4);
}

/* ===== 搜索建议 ===== */
.search-suggestions {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  max-height: 300px;
  overflow-y: auto;
  z-index: 1001;
  display: none;
}

.search-suggestions.visible {
  display: block;
}

.suggestion-item {
  padding: var(--spacing-md);
  cursor: pointer;
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition-fast);
}

.suggestion-item:last-child {
  border-bottom: none;
}

.suggestion-item:hover,
.suggestion-item.highlighted {
  background-color: var(--bg-hover);
}

.suggestion-title {
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 2px;
}

.suggestion-category {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ===== 响应式设计 ===== */
@media (max-width: 1024px) {
  .content-header {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-md);
  }

  .content-filters {
    width: 100%;
    justify-content: space-between;
  }

  .tools-grid {
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-md);
  }
}

@media (max-width: 768px) {
  .header-container {
    padding: 0 var(--spacing-md);
  }

  .search-container {
    margin: 0 var(--spacing-md);
    max-width: none;
  }

  .mobile-menu-toggle {
    display: flex;
  }

  .main {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: fixed;
    top: var(--header-height);
    left: 0;
    bottom: 0;
    width: var(--sidebar-width);
    transform: translateX(-100%);
    z-index: 999;
    box-shadow: var(--shadow-lg);
  }

  .sidebar.mobile-open {
    transform: translateX(0);
  }

  .content {
    padding: var(--spacing-lg);
  }

  .content-title h2 {
    font-size: 1.5rem;
  }

  .content-filters {
    flex-direction: column;
    align-items: stretch;
    gap: var(--spacing-md);
  }

  .filter-group {
    justify-content: space-between;
  }

  .tools-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }

  .back-to-top {
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    width: 44px;
    height: 44px;
  }
}

@media (max-width: 480px) {
  .header-brand .site-title {
    display: none;
  }

  .search-container {
    margin: 0 var(--spacing-sm);
  }

  .content {
    padding: var(--spacing-md);
  }

  .tool-card {
    padding: var(--spacing-md);
  }

  .card-icon {
    width: 40px;
    height: 40px;
    font-size: 1.25rem;
  }
}

/* ===== 辅助类 ===== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.fade-in {
  animation: fadeIn 0.5s ease-in-out;
}

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

.slide-in-left {
  animation: slideInLeft 0.3s ease-out;
}

@keyframes slideInLeft {
  from { transform: translateX(-100%); }
  to { transform: translateX(0); }
}

/* ===== 打印样式 ===== */
@media print {
  .header,
  .sidebar,
  .back-to-top,
  .search-suggestions {
    display: none !important;
  }

  .main {
    grid-template-columns: 1fr;
    padding-top: 0;
  }

  .content {
    background-color: white;
    padding: 0;
  }

  .tool-card {
    break-inside: avoid;
    box-shadow: none;
    border: 1px solid #ddd;
  }
}