/* ========================================
   MySQL 教程网站 - 现代化样式表
   ======================================== */

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

/* CSS 变量 - 主题色彩 */
:root {
    /* 主色调 - MySQL 蓝 */
    --primary-color: #00758f;
    --primary-dark: #005a6e;
    --primary-light: #00a3bf;
    
    /* 强调色 - 活力橙 */
    --accent-color: #f29111;
    --accent-hover: #e07d00;
    
    /* 中性色 */
    --text-primary: #1a1a2e;
    --text-secondary: #4a4a68;
    --text-muted: #6b7280;
    
    /* 背景色 */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    
    /* 边框色 */
    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;
    
    /* 功能色 */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --info: #3b82f6;
    
    /* 代码主题 */
    --code-bg: #1e293b;
    --code-text: #e2e8f0;
    --code-comment: #64748b;
    --code-keyword: #f472b6;
    --code-string: #a5f3fc;
    --code-number: #fbbf24;
    --code-function: #a78bfa;
    
    /* 布局 */
    --sidebar-width: 280px;
    --header-height: 60px;
    --max-content-width: 1200px;
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* 圆角 */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* 过渡 */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
}

/* 基础样式 */
html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', 'PingFang SC', 'Microsoft YaHei', Arial, sans-serif;
    line-height: 1.7;
    color: var(--text-primary);
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    min-height: 100vh;
}

/* 布局 */
.layout {
    display: flex;
    min-height: 100vh;
}

/* ========================================
   侧边栏样式
   ======================================== */
.sidebar {
    width: var(--sidebar-width);
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
    border-right: 1px solid var(--border-light);
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    overflow-y: auto;
    z-index: 1000;
    transition: transform var(--transition-base);
}

.sidebar::-webkit-scrollbar {
    width: 6px;
}

.sidebar::-webkit-scrollbar-track {
    background: transparent;
}

.sidebar::-webkit-scrollbar-thumb {
    background: var(--border-medium);
    border-radius: 3px;
}

.sidebar-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
    padding: 2rem 1.5rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.sidebar-header::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    animation: pulse 4s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.sidebar-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    position: relative;
    z-index: 1;
    letter-spacing: 1px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.sidebar-header h1 a {
    color: inherit;
    text-decoration: none;
}

/* 导航菜单 */
.tree-nav {
    padding: 1.5rem 0;
}

.tree {
    list-style: none;
}

.tree > li {
    margin: 0;
}

.tree > li > a {
    display: flex;
    align-items: center;
    padding: 1rem 1.5rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    border-left: 4px solid transparent;
    transition: all var(--transition-fast);
    position: relative;
}

.tree > li > a::before {
    content: '📄';
    margin-right: 0.75rem;
    font-size: 1rem;
    opacity: 0.7;
    transition: transform var(--transition-fast);
}

.tree > li > a:hover {
    background: linear-gradient(90deg, rgba(0, 117, 143, 0.08) 0%, transparent 100%);
    border-left-color: var(--primary-light);
    color: var(--primary-color);
    padding-left: 1.75rem;
}

.tree > li > a:hover::before {
    transform: scale(1.1);
}

.tree > li.current > a,
.tree > li > a.active {
    background: linear-gradient(90deg, rgba(0, 117, 143, 0.15) 0%, rgba(0, 163, 191, 0.05) 100%);
    border-left-color: var(--primary-color);
    color: var(--primary-color);
    font-weight: 600;
}

.tree > li.current > a::before {
    content: '📖';
}

/* ========================================
   主内容区域
   ======================================== */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    padding: 0;
    min-height: 100vh;
}

/* 章节容器 */
.section {
    background: var(--bg-primary);
    margin: 2rem;
    padding: 2.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-light);
}

.section h2 {
    color: var(--primary-color);
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 3px solid var(--primary-light);
    position: relative;
}

.section h2::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 0;
    width: 60px;
    height: 3px;
    background: var(--accent-color);
}

.section h3 {
    color: var(--text-primary);
    font-size: 1.5rem;
    font-weight: 600;
    margin-top: 2rem;
    margin-bottom: 1rem;
    padding-left: 1rem;
    border-left: 4px solid var(--accent-color);
}

.section h4 {
    color: var(--text-secondary);
    font-size: 1.15rem;
    font-weight: 600;
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
}

.section p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

.section ul, .section ol {
    margin: 1rem 0;
    padding-left: 2rem;
    color: var(--text-secondary);
}

.section li {
    margin: 0.5rem 0;
}

/* ========================================
   特性卡片网格
   ======================================== */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.feature-card {
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    padding: 1.75rem;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-light);
    border-top: 4px solid var(--primary-light);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(0, 117, 143, 0.03) 0%, transparent 100%);
    opacity: 0;
    transition: opacity var(--transition-base);
}

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

.feature-card:hover::before {
    opacity: 1;
}

.feature-card h3 {
    margin-top: 0;
    margin-bottom: 0.75rem;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.feature-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 0;
}

/* ========================================
   代码块样式
   ======================================== */
.code-block {
    background: var(--code-bg);
    border-radius: var(--radius-md);
    margin: 1.5rem 0;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    border: 1px solid #334155;
    transition: all var(--transition-base);
    position: relative;
}

.code-block.collapsed {
    overflow: visible;
}

.code-block:hover {
    box-shadow: var(--shadow-xl);
}

.code-block pre {
    padding: 1.25rem;
    overflow-x: auto;
    font-size: 0.9rem;
    line-height: 1.6;
    max-height: 500px;
    transition: all 0.3s ease;
}

.code-block pre::-webkit-scrollbar {
    height: 8px;
    width: 8px;
}

.code-block pre::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 4px;
}

.code-block pre::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 4px;
}

.code-block pre::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

.code-block code {
    font-family: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;
    color: var(--code-text);
    display: block;
}

/* 代码块工具栏 */
.code-toolbar {
    display: flex;
    gap: 0.5rem;
    justify-content: flex-end;
    padding: 0.5rem 1rem;
    background: rgba(0, 0, 0, 0.2);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    z-index: 10;
}

.code-block.collapsed .code-toolbar {
    position: relative;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    background: rgba(0, 0, 0, 0.3);
}

.code-toolbar button {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    padding: 0.25rem 0.6rem;
    font-size: 0.8rem;
    cursor: pointer;
    color: #fff;
    transition: all 0.2s;
    font-weight: 500;
    white-space: nowrap;
}

.code-toolbar button:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-1px);
}

.code-toolbar button:active {
    transform: translateY(0);
}

.code-toolbar .toggle-btn {
    background: rgba(59, 130, 246, 0.2);
    border-color: rgba(59, 130, 246, 0.3);
    min-width: 50px;
}

.code-toolbar .toggle-btn:hover {
    background: rgba(59, 130, 246, 0.3);
    border-color: rgba(59, 130, 246, 0.5);
}

.code-toolbar .copy-btn {
    background: rgba(16, 185, 129, 0.2);
    border-color: rgba(16, 185, 129, 0.3);
}

.code-toolbar .copy-btn:hover {
    background: rgba(16, 185, 129, 0.3);
    border-color: rgba(16, 185, 129, 0.5);
}

.code-toolbar .copy-btn.copied {
    background: rgba(16, 185, 129, 0.4);
}

/* 折叠状态 - 只隐藏 pre 内容，保留工具栏 */
.code-block.collapsed pre {
    max-height: 0 !important;
    padding: 0 !important;
    opacity: 0;
    overflow: hidden;
    visibility: hidden !important;
    height: 0 !important;
}

.code-block.collapsed {
    padding-bottom: 0;
}

/* SQL 语法高亮 */
.code-block .kwd { color: var(--code-keyword); font-weight: 600; }
.code-block .str { color: var(--code-string); }
.code-block .com { color: var(--code-comment); font-style: italic; }
.code-block .num { color: var(--code-number); }
.code-block .func { color: var(--code-function); }
.code-block .type { color: #60a5fa; }

/* ========================================
   表格样式
   ======================================== */
.comparison-table {
    margin: 1.5rem 0;
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.comparison-table table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-primary);
}

.comparison-table th,
.comparison-table td {
    padding: 1rem 1.25rem;
    text-align: left;
    border-bottom: 1px solid var(--border-light);
}

.comparison-table th {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.85rem;
    letter-spacing: 0.5px;
}

.comparison-table tr:last-child td {
    border-bottom: none;
}

.comparison-table tr:hover {
    background: var(--bg-secondary);
}

/* ========================================
   Mermaid 图表容器
   ======================================== */
.mermaid {
    margin: 2rem 0;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-light);
    text-align: center;
}

.mermaid svg {
    max-width: 100%;
    height: auto;
}

/* ========================================
   图注样式
   ======================================== */
.figure-caption {
    background: var(--bg-secondary);
    padding: 1rem 1.25rem;
    border-radius: var(--radius-md);
    margin: 1rem 0;
    border-left: 4px solid var(--info);
}

.figure-caption strong {
    color: var(--primary-color);
    display: block;
    margin-bottom: 0.5rem;
}

.figure-caption ul {
    list-style: none;
    padding-left: 0;
    margin: 0;
}

.figure-caption li {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin: 0.35rem 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.color-dot {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    display: inline-block;
    flex-shrink: 0;
}

.line-sample {
    font-size: 1.2rem;
    color: var(--primary-color);
}

/* ========================================
   Details/Summary 样式
   ======================================== */
details {
    margin: 1rem 0;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border-light);
}

details summary {
    cursor: pointer;
    padding: 1rem 1.25rem;
    background: linear-gradient(90deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
    font-weight: 600;
    color: var(--primary-color);
    list-style: none;
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: background var(--transition-fast);
}

details summary:hover {
    background: linear-gradient(90deg, var(--bg-tertiary) 0%, var(--border-light) 100%);
}

details summary::after {
    content: '+';
    font-size: 1.5rem;
    font-weight: 300;
    transition: transform var(--transition-fast);
}

details[open] summary::after {
    transform: rotate(45deg);
}

details[open] summary {
    border-bottom: 1px solid var(--border-light);
}

details > div {
    padding: 1.25rem;
    background: var(--bg-primary);
}

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

/* 移动导航按钮 */
.menu-toggle {
    display: none;
    position: fixed;
    top: 1rem;
    left: 1rem;
    z-index: 1001;
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 1.25rem;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-fast);
}

.menu-toggle:hover {
    background: var(--primary-dark);
    transform: scale(1.05);
}

.menu-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
    opacity: 0;
    transition: opacity var(--transition-base);
}

.menu-overlay.active {
    opacity: 1;
}

@media (max-width: 1024px) {
    .menu-toggle {
        display: flex;
        align-items: center;
        gap: 0.5rem;
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .sidebar {
        transform: translateX(-100%);
        box-shadow: var(--shadow-xl);
    }
    
    .sidebar.active {
        transform: translateX(0);
    }
    
    .section {
        margin: 1rem;
    }
}

@media (max-width: 768px) {
    .section {
        padding: 1.5rem;
    }
    
    .section h2 {
        font-size: 1.5rem;
    }
    
    .section h3 {
        font-size: 1.25rem;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
    
    .comparison-table {
        overflow-x: auto;
    }
    
    .comparison-table table {
        min-width: 600px;
    }
    
    .hero-banner h1 {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .path-item {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    .step {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    .project-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-banner {
        padding: 2rem 1rem;
    }
    
    .hero-banner h1 {
        font-size: 1.5rem;
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 250px;
        text-align: center;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}

/* ========================================
   工具类
   ======================================== */
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }

/* ========================================
   动画效果
   ======================================== */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

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

/* ========================================
   打印样式
   ======================================== */
@media print {
    .sidebar { display: none; }
    .main-content { margin-left: 0; }
    .section { box-shadow: none; border: none; }
    .code-block { background: #f5f5f5; color: #333; }
}

/* ========================================
   章节页面特有样式
   ======================================== */
.content {
    color: var(--text-secondary);
}

.content > h2 {
    font-size: 2.25rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    padding-bottom: 1rem;
    border-bottom: 3px solid var(--border-light);
    margin-bottom: 2rem;
}

/* 高亮提示框 */
.tip-box {
    background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%);
    border-left: 4px solid var(--success);
    padding: 1.25rem 1.5rem;
    border-radius: var(--radius-md);
    margin: 1.5rem 0;
}

.tip-box.warning {
    background: linear-gradient(135deg, #fffbeb 0%, #fef3c7 100%);
    border-left-color: var(--warning);
}

.tip-box.error {
    background: linear-gradient(135deg, #fef2f2 0%, #fee2e2 100%);
    border-left-color: var(--error);
}

.tip-box.info {
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    border-left-color: var(--info);
}

.tip-box strong {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

/* 代码行号 */
.code-block pre {
    counter-reset: line;
}

.code-block pre code {
    display: block;
}

/* 表格响应式包装 */
.table-wrapper {
    overflow-x: auto;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

/* 徽章样式 */
.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-right: 0.5rem;
}

.badge-primary {
    background: rgba(0, 117, 143, 0.1);
    color: var(--primary-color);
}

.badge-success {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
}

.badge-warning {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning);
}

.badge-error {
    background: rgba(239, 68, 68, 0.1);
    color: var(--error);
}