: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: #F8FAFC;
    
    /* 文字颜色 */
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-muted: #999999;
    --text-inverse: #FFFFFF;
    
    /* 边框和阴影 */
    --border-color: #E2E8F0;
    --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-medium: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-heavy: 0 8px 24px rgba(0, 0, 0, 0.12);
    
    /* 间距 */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;
    
    /* 圆角 */
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --border-radius-lg: 16px;
    
    /* 动画 */
    --transition: all 0.3s ease;
    --transition-fast: all 0.15s ease;
    
    /* 布局 */
    --sidebar-width: 240px;
    --header-height: 60px;
}

[data-theme="dark"] {
    --bg-primary: #1A1A1A;
    --bg-secondary: #2A2A2A;
    --bg-card: #2D2D2D;
    --bg-hover: #3A3A3A;
    
    --text-primary: #FFFFFF;
    --text-secondary: #CCCCCC;
    --text-muted: #888888;
    --text-inverse: #1A1A1A;
    
    --border-color: #404040;
    --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-medium: 0 4px 12px rgba(0, 0, 0, 0.3);
    --shadow-heavy: 0 8px 24px rgba(0, 0, 0, 0.4);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: var(--transition);
}

.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* 顶部导航栏 */
.header {
    height: var(--header-height);
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--spacing-lg);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: var(--transition);
}

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

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

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

.sidebar-toggle span {
    display: block;
    width: 18px;
    height: 2px;
    background-color: var(--text-primary);
    margin: 3px 0;
    transition: var(--transition-fast);
}

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

.logo-icon {
    font-size: 24px;
}

.logo h1 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
}

.search-container {
    flex: 1;
    max-width: 400px;
    margin: 0 var(--spacing-lg);
    position: relative;
}

.search-input {
    width: 100%;
    height: 40px;
    padding: 0 var(--spacing-md);
    padding-right: 40px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 14px;
    transition: var(--transition);
}

.search-input:focus {
    outline: none;
    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;
    cursor: pointer;
    color: var(--text-muted);
    transition: var(--transition-fast);
}

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

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

.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    border-radius: var(--border-radius-sm);
    color: var(--text-muted);
    transition: var(--transition-fast);
    position: relative;
}

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

.sun-icon,
.moon-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    transition: var(--transition);
}

[data-theme="light"] .moon-icon,
[data-theme="dark"] .sun-icon {
    opacity: 0;
    transform: translate(-50%, -50%) rotate(180deg);
}

/* 主内容区 */
.main-content {
    flex: 1;
    display: flex;
    overflow: hidden;
}

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

.sidebar-nav {
    padding: 0 var(--spacing-md);
}

.sidebar-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: var(--spacing-md);
    padding: 0 var(--spacing-sm);
}

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

.nav-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: var(--transition-fast);
    margin-bottom: 2px;
}

.nav-item:hover {
    background-color: var(--bg-hover);
}

.nav-item.active {
    background-color: rgba(91, 106, 255, 0.1);
    color: var(--primary-color);
}

.nav-icon {
    font-size: 16px;
    width: 20px;
    text-align: center;
}

.nav-text {
    flex: 1;
    font-size: 14px;
    font-weight: 500;
}

.nav-count {
    font-size: 12px;
    color: var(--text-muted);
    background-color: var(--bg-secondary);
    padding: 2px 6px;
    border-radius: 10px;
    min-width: 20px;
    text-align: center;
}

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

/* 主内容 */
.content {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-xl);
}

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

.content-title {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

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

/* 工具网格 */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.tool-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    transition: var(--transition);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

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

.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::before {
    transform: scaleX(1);
}

.card-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    margin-bottom: var(--spacing-md);
    color: white;
}

.card-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.card-description {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: var(--spacing-md);
}

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

.card-tag {
    font-size: 12px;
    color: var(--primary-color);
    background-color: rgba(91, 106, 255, 0.1);
    padding: 2px 8px;
    border-radius: 12px;
    font-weight: 500;
}

.card-action {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--primary-color);
    color: var(--text-inverse);
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-fast);
}

.card-action:hover {
    background-color: var(--secondary-color);
    transform: translateY(-1px);
}

/* 加载骨架屏 */
.loading-skeleton {
    display: none;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.skeleton-card {
    height: 200px;
    background: linear-gradient(90deg, 
        var(--bg-secondary) 25%, 
        var(--bg-hover) 50%, 
        var(--bg-secondary) 75%);
    background-size: 200% 100%;
    animation: loading 1.5s infinite;
    border-radius: var(--border-radius);
}

@keyframes loading {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

/* 无结果提示 */
.no-results {
    text-align: center;
    padding: var(--spacing-xxl);
    color: var(--text-muted);
}

.no-results-icon {
    font-size: 48px;
    margin-bottom: var(--spacing-md);
}

.no-results h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.no-results p {
    font-size: 14px;
    color: var(--text-muted);
}

/* 工具模态框 */
.tool-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 90%;
    max-height: 90%;
    width: 800px;
    height: 600px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    animation: slideIn 0.3s ease;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-secondary);
}

.modal-header h3 {
    margin: 0;
    font-size: 1.25rem;
    color: var(--text-primary);
}

.modal-close {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-secondary);
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: all 0.3s ease;
}

.modal-close:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
    transform: rotate(90deg);
}

.tool-iframe {
    flex: 1;
    width: 100%;
    height: 100%;
    border: none;
    background: var(--bg-primary);
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideIn {
    from { 
        opacity: 0;
        transform: translateY(-50px) scale(0.9);
    }
    to { 
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

/* 响应式设计 */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: -100%;
        top: var(--header-height);
        height: calc(100vh - var(--header-height));
        z-index: 99;
        box-shadow: var(--shadow-heavy);
    }
    
    .sidebar.open {
        left: 0;
    }
    
    .sidebar-toggle {
        display: block;
    }
    
    .content {
        padding: var(--spacing-md);
    }
    
    .content-title {
        font-size: 24px;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .search-container {
        max-width: 200px;
        margin: 0 var(--spacing-sm);
    }
    
    .logo h1 {
        display: none;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .tools-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .content {
        padding: var(--spacing-lg);
    }
}

@media (min-width: 1025px) {
    .tools-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (min-width: 1440px) {
    .tools-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* 侧边栏遮罩层 */
.sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 98;
    display: none;
}

@media (max-width: 768px) {
    .sidebar-overlay.active {
        display: block;
    }
}

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 8px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

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

/* 焦点样式 */
*:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

button:focus,
input:focus {
    outline: none;
}