/* ============================================
   CSS变量定义 - 明暗主题
   ============================================ */
: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: #F9FAFB;
    
    /* 文字颜色 */
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-muted: #999999;
    
    /* 边框颜色 */
    --border-color: #E5E7EB;
    --border-hover: #D1D5DB;
    
    /* 阴影 */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.12);
    
    /* 间距 */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    
    /* 圆角 */
    --radius: 12px;
    --radius-sm: 8px;
    
    /* 过渡 */
    --transition: all 0.3s ease;
}

/* 暗色主题 */
[data-theme="dark"] {
    --bg-primary: #1A1B23;
    --bg-secondary: #242530;
    --bg-card: #2A2B37;
    --bg-hover: #323343;
    
    --text-primary: #E5E7EB;
    --text-secondary: #9CA3AF;
    --text-muted: #6B7280;
    
    --border-color: #374151;
    --border-hover: #4B5563;
    
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.5);
}

/* ============================================
   基础样式重置
   ============================================ */
* {
    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', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   顶部导航栏
   ============================================ */
.top-nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    height: 60px;
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--spacing-md);
    gap: var(--spacing-md);
}

.nav-left {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
}

.logo-icon {
    width: 28px;
    height: 28px;
    color: var(--primary-color);
}

.logo-text {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-center {
    flex: 1;
    max-width: 600px;
    margin: 0 auto;
}

.search-container {
    position: relative;
    display: flex;
    align-items: center;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: var(--spacing-sm) var(--spacing-md);
    transition: var(--transition);
}

.search-container:focus-within {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(91, 106, 255, 0.1);
}

.search-icon {
    width: 20px;
    height: 20px;
    color: var(--text-muted);
    flex-shrink: 0;
    margin-right: var(--spacing-sm);
}

.search-input {
    flex: 1;
    border: none;
    outline: none;
    background: transparent;
    color: var(--text-primary);
    font-size: 0.9375rem;
    padding: var(--spacing-xs) 0;
}

.search-input::placeholder {
    color: var(--text-muted);
}

.search-clear {
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    transition: var(--transition);
    margin-left: var(--spacing-sm);
}

.search-clear:hover {
    color: var(--text-primary);
}

.nav-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex-shrink: 0;
}

.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    border-radius: var(--radius-sm);
    transition: var(--transition);
    position: relative;
    width: 40px;
    height: 40px;
}

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

.theme-icon {
    width: 20px;
    height: 20px;
    position: absolute;
    transition: var(--transition);
}

.sun-icon {
    opacity: 1;
    transform: rotate(0deg);
}

.moon-icon {
    opacity: 0;
    transform: rotate(90deg);
}

[data-theme="dark"] .sun-icon {
    opacity: 0;
    transform: rotate(90deg);
}

[data-theme="dark"] .moon-icon {
    opacity: 1;
    transform: rotate(0deg);
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    color: var(--text-primary);
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.mobile-menu-toggle:hover {
    background-color: var(--bg-secondary);
}

.mobile-menu-toggle svg {
    width: 24px;
    height: 24px;
}

/* ============================================
   主布局
   ============================================ */
.main-layout {
    display: grid;
    grid-template-columns: 240px 1fr;
    min-height: calc(100vh - 60px);
}

/* ============================================
   左侧分类导航
   ============================================ */
.sidebar {
    background-color: var(--bg-primary);
    border-right: 1px solid var(--border-color);
    padding: var(--spacing-lg);
    overflow-y: auto;
    transition: var(--transition);
    position: sticky;
    top: 60px;
    height: calc(100vh - 60px);
}

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

.sidebar-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
}

.sidebar-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

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

.sidebar-toggle svg {
    width: 20px;
    height: 20px;
}

.category-nav {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.category-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: none;
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-secondary);
    font-size: 0.9375rem;
    text-align: left;
    width: 100%;
    position: relative;
}

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

.category-item.active {
    background: linear-gradient(135deg, rgba(91, 106, 255, 0.1), rgba(140, 84, 255, 0.1));
    color: var(--primary-color);
    font-weight: 500;
}

.category-item.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 60%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 0 3px 3px 0;
}

.category-icon {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

.category-name {
    flex: 1;
}

.category-count {
    background-color: var(--bg-secondary);
    color: var(--text-muted);
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 500;
    min-width: 24px;
    text-align: center;
}

.category-item.active .category-count {
    background-color: rgba(91, 106, 255, 0.2);
    color: var(--primary-color);
}

/* ============================================
   主内容区
   ============================================ */
.main-content {
    padding: var(--spacing-xl) var(--spacing-lg);
    max-width: 1600px;
    margin: 0 auto;
    width: 100%;
}

.content-header {
    margin-bottom: var(--spacing-xl);
}

.page-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.page-subtitle {
    font-size: 1rem;
    color: var(--text-secondary);
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

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

.tool-card.original-tool {
    border-color: rgba(91, 106, 255, 0.3);
    background: linear-gradient(135deg, rgba(91, 106, 255, 0.02), rgba(140, 84, 255, 0.02));
}

.tool-card.original-tool::before {
    background: linear-gradient(90deg, #5B6AFF, #8C54FF);
    transform: scaleX(1);
    opacity: 0.8;
}

.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);
    transition: var(--transition);
}

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

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

.card-header {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
}

.card-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-sm);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: white;
    font-size: 1.5rem;
    font-weight: 700;
}

.card-icon svg {
    width: 24px;
    height: 24px;
}

.card-info {
    flex: 1;
    min-width: 0;
}

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

.card-description {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.5;
    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-top: var(--spacing-sm);
}

.card-tag {
    display: inline-block;
    padding: 4px 10px;
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 500;
    transition: var(--transition);
}

.card-action {
    margin-top: auto;
    padding: var(--spacing-md);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.9375rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
}

.card-action:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(91, 106, 255, 0.4);
}

.card-action:active {
    transform: translateY(0);
}

/* ============================================
   工具标识徽章
   ============================================ */
.tool-badge {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    z-index: 10;
    box-shadow: var(--shadow-sm);
}

.original-badge {
    background: linear-gradient(135deg, #5B6AFF, #8C54FF);
    color: white;
}

.featured-badge {
    background: linear-gradient(135deg, #F59E0B, #EF4444);
    color: white;
    top: calc(var(--spacing-md) + 28px);
}

.tool-card:hover .tool-badge {
    transform: scale(1.05);
    transition: var(--transition);
}

/* ============================================
   空状态和加载状态
   ============================================ */
.empty-state {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-md);
    grid-column: 1 / -1;
}

.empty-icon {
    width: 64px;
    height: 64px;
    color: var(--text-muted);
    margin: 0 auto var(--spacing-md);
    opacity: 0.5;
}

.empty-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.empty-description {
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

.loading-state {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    grid-column: 1 / -1;
}

.skeleton-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: var(--spacing-lg);
    height: 280px;
    animation: skeleton-loading 1.5s ease-in-out infinite;
}

@keyframes skeleton-loading {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

/* ============================================
   移动端遮罩层
   ============================================ */
.mobile-overlay {
    display: none;
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 90;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.mobile-overlay.active {
    display: block;
    opacity: 1;
}

/* ============================================
   响应式设计
   ============================================ */

/* 平板端 */
@media (min-width: 769px) and (max-width: 1024px) {
    .tools-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .main-layout {
        grid-template-columns: 200px 1fr;
    }
    
    .sidebar {
        padding: var(--spacing-md);
    }
}

/* 移动端 */
@media (max-width: 768px) {
    .nav-center {
        max-width: none;
        flex: 1;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .main-layout {
        grid-template-columns: 1fr;
    }
    
    .sidebar {
        position: fixed;
        top: 60px;
        left: 0;
        width: 280px;
        height: calc(100vh - 60px);
        z-index: 95;
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        box-shadow: var(--shadow-lg);
    }
    
    .sidebar.active {
        transform: translateX(0);
    }
    
    .sidebar-toggle {
        display: flex;
    }
    
    .main-content {
        padding: var(--spacing-lg) var(--spacing-md);
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .page-title {
        font-size: 1.5rem;
    }
    
    .logo-text {
        display: none;
    }
    
    .nav-container {
        padding: 0 var(--spacing-sm);
    }
}

/* 小屏幕移动端 */
@media (max-width: 480px) {
    .main-content {
        padding: var(--spacing-md) var(--spacing-sm);
    }
    
    .content-header {
        margin-bottom: var(--spacing-lg);
    }
    
    .page-title {
        font-size: 1.25rem;
    }
    
    .tool-card {
        padding: var(--spacing-md);
    }
}

/* ============================================
   无障碍支持
   ============================================ */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* 焦点样式 */
button:focus-visible,
input:focus-visible,
.category-item:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* 打印样式 */
@media print {
    .top-nav,
    .sidebar,
    .mobile-overlay {
        display: none;
    }
    
    .main-layout {
        grid-template-columns: 1fr;
    }
    
    .tool-card {
        break-inside: avoid;
    }
}