/* CSS 变量定义 */
:root {
    /* 主色调 */
    --primary-color: #5B6AFF;
    --secondary-color: #8C54FF;
    --accent-color: #667EEA;
    
    /* 背景色 - 亮色主题 */
    --bg-primary: #FFFFFF;
    --bg-secondary: #F5F7FA;
    --bg-card: #FFFFFF;
    --bg-overlay: rgba(255, 255, 255, 0.9);
    
    /* 文字颜色 - 亮色主题 */
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-muted: #999999;
    --text-inverse: #FFFFFF;
    
    /* 边框和阴影 */
    --border-color: #E5E7EB;
    --border-radius: 12px;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --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, 0.2);
    
    /* 尺寸 */
    --header-height: 60px;
    --sidebar-width: 240px;
    --sidebar-collapsed-width: 60px;
    --grid-gap: 24px;
    
    /* 动画 */
    --transition: all 0.3s ease;
    --transition-fast: all 0.2s ease;
}

/* 暗色主题 */
[data-theme='dark'] {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-card: #242424;
    --bg-overlay: rgba(26, 26, 26, 0.9);
    
    --text-primary: #ffffff;
    --text-secondary: #b3b3b3;
    --text-muted: #888888;
    
    --border-color: #404040;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
}

/* 基础重置和字体 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

/* 顶部导航栏 */
.top-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--bg-overlay);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    z-index: 1000;
    transition: var(--transition);
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 16px;
}

.sidebar-toggle {
    display: none;
    background: none;
    border: none;
    padding: 8px;
    cursor: pointer;
    border-radius: 8px;
    transition: var(--transition);
}

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

.hamburger {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--text-primary);
    position: relative;
    transition: var(--transition);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition);
}

.hamburger::before {
    top: -6px;
}

.hamburger::after {
    top: 6px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--text-primary);
}

.logo-icon {
    width: 32px;
    height: 32px;
    color: var(--primary-color);
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    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: 500px;
    margin: 0 32px;
}

.search-container {
    position: relative;
    width: 100%;
}

.search-input {
    width: 100%;
    height: 40px;
    padding: 0 48px 0 16px;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 14px;
    outline: none;
    transition: var(--transition);
}

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

.search-btn {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    padding: 8px;
    cursor: pointer;
    border-radius: 50%;
    color: var(--text-muted);
    transition: var(--transition);
}

.search-btn:hover {
    color: var(--primary-color);
    background: var(--bg-secondary);
}

.search-btn svg {
    width: 16px;
    height: 16px;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.theme-toggle {
    background: none;
    border: none;
    padding: 8px;
    cursor: pointer;
    border-radius: 8px;
    color: var(--text-primary);
    transition: var(--transition);
    position: relative;
}

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

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

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

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

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

/* 主容器 */
.main-container {
    margin-top: var(--header-height);
    display: grid;
    grid-template-columns: var(--sidebar-width) 1fr;
    min-height: calc(100vh - var(--header-height));
    transition: var(--transition);
}

/* 左侧边栏 */
.sidebar {
    background: var(--bg-card);
    border-right: 1px solid var(--border-color);
    padding: 24px 0;
    overflow-y: auto;
    transition: var(--transition);
}

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

.category-item {
    margin-bottom: 4px;
}

.category-btn {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 24px;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    font-size: 14px;
    text-align: left;
}

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

.category-item.active .category-btn {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    background-size: 200% 200%;
    color: var(--text-inverse);
    font-weight: 600;
}

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

.category-text {
    flex: 1;
}

.category-count {
    background: rgba(255, 255, 255, 0.2);
    color: var(--text-inverse);
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
}

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

/* 主内容区 */
.main-content {
    padding: 32px;
    overflow-y: auto;
}

.content-header {
    margin-bottom: 32px;
}

.page-title {
    font-size: 32px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.page-subtitle {
    font-size: 16px;
    color: var(--text-secondary);
}

/* 工具网格 */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--grid-gap);
    margin-bottom: 32px;
}

/* 工具卡片 */
.tool-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 24px;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transition: var(--transition);
}

.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;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
    color: white;
    font-size: 24px;
}

.card-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
    line-height: 1.4;
}

.card-description {
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.5;
    margin-bottom: 16px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
}

.card-tag {
    background: var(--bg-secondary);
    color: var(--text-muted);
    padding: 4px 8px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 500;
}

.card-action {
    width: 100%;
    padding: 10px 16px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.card-action:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

/* 加载骨架屏 */
.loading-skeleton {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--grid-gap);
}

.skeleton-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 24px;
    position: relative;
    overflow: hidden;
}

.skeleton-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
    animation: skeleton-loading 1.5s infinite;
}

@keyframes skeleton-loading {
    0% { left: -100%; }
    100% { left: 100%; }
}

.skeleton-card::after {
    content: '';
    display: block;
    height: 200px;
    background: var(--bg-secondary);
    border-radius: 8px;
}

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 64px 32px;
    color: var(--text-muted);
}

.empty-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 16px;
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-secondary);
}

.empty-state p {
    font-size: 14px;
}

/* 背景装饰 */
.bg-decoration {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
    opacity: 0.03;
    background-image: 
        radial-gradient(circle at 20% 80%, var(--primary-color) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, var(--secondary-color) 0%, transparent 50%);
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .tools-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
        gap: 20px;
    }
    
    .main-content {
        padding: 24px;
    }
    
    .nav-center {
        margin: 0 16px;
    }
}

@media (max-width: 768px) {
    .main-container {
        grid-template-columns: 1fr;
    }
    
    .sidebar {
        position: fixed;
        left: -100%;
        top: var(--header-height);
        width: var(--sidebar-width);
        height: calc(100vh - var(--header-height));
        z-index: 999;
        box-shadow: var(--shadow-lg);
        transition: var(--transition);
    }
    
    .sidebar.open {
        left: 0;
    }
    
    .sidebar-toggle {
        display: flex;
    }
    
    .nav-center {
        margin: 0 12px;
        max-width: none;
        flex: 1;
    }
    
    .search-container {
        max-width: 300px;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    
    .main-content {
        padding: 16px;
    }
    
    .content-header {
        margin-bottom: 24px;
    }
    
    .page-title {
        font-size: 24px;
    }
    
    .top-nav {
        padding: 0 16px;
    }
    
    .logo-text {
        display: none;
    }
    
    .category-btn {
        padding: 16px 24px;
    }
}

@media (max-width: 480px) {
    .tool-card {
        padding: 20px;
    }
    
    .card-icon {
        width: 40px;
        height: 40px;
    }
    
    .search-input {
        font-size: 16px; /* 防止iOS缩放 */
    }
}

/* 侧边栏收缩状态 */
.sidebar.collapsed {
    width: var(--sidebar-collapsed-width);
}

.sidebar.collapsed .category-text,
.sidebar.collapsed .category-count {
    display: none;
}

.sidebar.collapsed .category-btn {
    justify-content: center;
    padding: 12px;
}

/* 主题切换动画 */
* {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

/* 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: 3px;
}

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