/* 临界态AI教育实战课 - 专业蓝色调现代简洁风格 */

/* ==================== 全局变量 ==================== */
:root {
    /* 暖黄色调色板 */
    --color-primary: #1e40af; /* 深蓝色 */
    --color-primary-light: #dbeafe; /* 浅蓝色背景 */
    --color-primary-dark: #1e3a8a; /* 更深的蓝 */
    --color-secondary: #f1f5f9; /* 浅灰蓝背景 */

    /* 中性色 */
    --color-bg: #f8fafc; /* 极浅灰蓝背景 */
    --color-surface: #f1f5f9; /* 浅蓝灰表面 */
    --color-text: #0f172a; /* 深色文字 */
    --color-text-secondary: #475569; /* 次要文字 */
    --color-border: #e2e8f0; /* 边框色 */

    /* 功能色 */
    --color-success: #10B981;
    --color-warning: #F59E0B;
    --color-info: #3B82F6;
    --color-danger: #EF4444;

    /* 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);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);

    /* 层级 */
    --z-content: 1;
    --z-header: 1000;
    --z-floating: 1020;
    --z-backdrop: 1050;
    --z-sidebar: 1100;
    --z-modal: 1200;

    /* 圆角 */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;

    /* 间距 */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
}

/* ==================== 全局重置 ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB',
                 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    line-height: 1.75;
    color: var(--color-text);
    background-color: var(--color-bg);
    font-size: 16px;
}

/* 移动端抽屉打开时禁止页面滚动 */
body.nav-open {
    overflow: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.2s ease;
}

button {
    font-family: inherit;
    border: none;
    background: none;
    cursor: pointer;
}

/* ==================== 顶部导航栏 ==================== */
header {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: var(--z-header);
    box-shadow: var(--shadow-sm);
}

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

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

.logo {
    width: 120px;
    height: auto;
    display: block;
}

.site-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text);
    margin: 0;
}

.header-nav {
    display: flex;
    gap: var(--spacing-md);
}

/* ==================== 移动端导航按钮 ==================== */
.nav-toggle {
    display: none;
    height: 36px;
    padding: 0 var(--spacing-sm);
    border: 1px solid var(--color-border);
    background: var(--color-surface);
    border-radius: var(--radius-sm);
    align-items: center;
    justify-content: center;
    color: var(--color-text);
    font-size: 0.875rem;
    font-weight: 600;
}

.nav-toggle.active {
    background: var(--color-secondary);
    border-color: var(--color-primary-light);
    color: var(--color-primary-dark);
}

.header-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-primary);
    color: white;
    text-decoration: none;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    transition: transform 0.2s ease, background-color 0.2s ease;
}

.header-btn:hover {
    background: var(--color-primary-dark);
    transform: translateY(-1px);
}



/* ==================== 主容器 ==================== */
.main-container {
    display: flex;
    max-width: 1400px;
    margin: 0 auto;
    min-height: calc(100svh - 60px);
    min-height: calc(100dvh - 60px);
}

/* ==================== 左侧边栏 ==================== */
.sidebar {
    width: 320px;
    background: var(--color-surface);
    border-right: 1px solid var(--color-border);
    position: sticky;
    top: 60px;
    height: calc(100svh - 60px);
    height: calc(100dvh - 60px);
    overflow-y: auto;
    padding: var(--spacing-lg);
}

.course-nav {
    position: relative;
}

.nav-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-primary-light);
}

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

.course-list li {
    margin-bottom: var(--spacing-xs);
}

.course-list a {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    font-size: 0.95rem;
    transition: color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
    border-left: 3px solid transparent;
}

.course-list a:hover {
    background: var(--color-secondary);
    color: var(--color-primary-dark);
}

.course-list a.active {
    background: var(--color-secondary);
    color: var(--color-primary-dark);
    border-left-color: var(--color-primary);
    font-weight: 600;
}

/* ==================== 右侧内容区 ==================== */
.content-area {
    flex: 1;
    padding: var(--spacing-2xl) var(--spacing-xl);
    overflow-y: auto;
}

/* ==================== 移动端侧边栏遮罩 ==================== */
.sidebar-backdrop {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.35);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.2s ease, visibility 0.2s ease;
    z-index: var(--z-backdrop);
}

.sidebar-backdrop.show {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

.course-content {
    max-width: 900px;
    margin: 0 auto;
    word-wrap: break-word;
    overflow-wrap: break-word;
}

/* ==================== 课程网格 ==================== */
.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.course-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    transition: transform 0.2s ease;
    display: block;
}

.course-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary);
    transform: translateY(-2px);
}

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

.course-number {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-text);
    font-variant-numeric: tabular-nums;
}

.course-category {
    font-size: 0.75rem;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-weight: 600;
    min-width: 3.5rem;
    white-space: nowrap;
    text-align: center;
}

.course-category-入门 {
    background: #bfdbfe;
    color: #1e40af;
}

.course-category-基础 {
    background: #bfdbfe;
    color: #1e3a8a
}

.course-category-进阶 {
    background: #93c5fd
    color: #1e3a8a
}

.course-category-高级 {
    background: #3b82f6
    color: white
}

.course-category-专家 {
    background: #f3e8ff;
    color: #9333ea;
}

/* 重点课程标记 */
.course-featured {
    font-size: 0.75rem;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-weight: 600;
    background: linear-gradient(135deg, #fbbf24, #f59e0b);
    color: white;
    white-space: nowrap;
    text-shadow: 0 1px 1px rgba(0,0,0,0.1);
}

.course-card-featured {
    border-color: #f59e0b;
    box-shadow: 0 0 0 1px rgba(245, 158, 11, 0.2);
}

.course-card-featured:hover {
    border-color: #d97706;
    box-shadow: var(--shadow-md), 0 0 0 2px rgba(245, 158, 11, 0.3);
}

.course-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--color-text-secondary);
    font-size: 0.875rem;
    font-variant-numeric: tabular-nums;
}

.course-duration {
    color: var(--color-text-secondary);
    font-variant-numeric: tabular-nums;
}

.course-difficulty {
    font-size: 0.75rem;
    font-variant-numeric: tabular-nums;
}

.lesson-section {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    margin-bottom: var(--spacing-xl);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border);
}

.lesson-section:hover {
    box-shadow: var(--shadow-md);
}

.lesson-section h2 {
    font-size: 1.875rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    text-wrap: balance;
}

.lesson-download-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--color-primary-light);
    color: var(--color-primary-dark);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 600;
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s ease, background-color 0.2s ease;
    margin-left: auto;
    white-space: nowrap;
}

.lesson-download-btn:hover {
    background: var(--color-primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

.lesson-meta {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
    align-items: center;
    font-variant-numeric: tabular-nums;
}

.difficulty-badge {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
}

.difficulty-badge.difficulty-入门 {
    background: #bfdbfe;
    color: #1e40af;
}

.difficulty-badge.difficulty-基础 {
    background: #bfdbfe;
    color: #1e3a8a;
}

.difficulty-badge.difficulty-进阶 {
    background: #93c5fd
    color: #1e3a8a
}

.difficulty-badge.difficulty-高级 {
    background: #3b82f6
    color: white
}

.difficulty-badge.difficulty-专家 {
    background: #f3e8ff;
    color: #9333ea;
}

.estimated-time {
    color: var(--color-text-secondary);
    font-size: 0.875rem;
    display: flex;
    align-items: center;
}

.difficulty-stars {
    font-size: 0.875rem;
    color: #2563eb;
}

.tag {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--color-secondary);
    color: var(--color-primary-dark);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
}

.duration {
    color: var(--color-text-secondary);
    font-size: 0.875rem;
    display: flex;
    align-items: center;
    font-variant-numeric: tabular-nums;
}

.lesson-body {
    color: var(--color-text-secondary);
    line-height: 1.8;
    word-wrap: break-word;
    overflow-wrap: break-word;
    text-wrap: pretty;
}

.lesson-body p {
    margin-bottom: var(--spacing-md);
}

.lesson-body img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    margin: var(--spacing-md) 0;
}

.lesson-body ol,
.lesson-body ul {
    margin: 0 0 var(--spacing-md) 0;
    padding-left: 0;
    list-style-position: inside;
}

.lesson-body ol li,
.lesson-body ul li {
    margin-bottom: var(--spacing-sm);
    line-height: 1.8;
}

/* ==================== 课程内容样式 ==================== */
.lesson-intro {
    background: var(--color-secondary);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
    border-left: 4px solid var(--color-primary);
    word-wrap: break-word;
    overflow-wrap: break-word;
}

.lesson-intro p {
    margin: 0;
    color: var(--color-primary-dark);
    font-weight: 500;
}

.content-section {
    margin-bottom: var(--spacing-2xl);
    padding: var(--spacing-lg);
    background: var(--color-bg);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
}

.content-section h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    color: var(--color-text);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-primary-light);
    text-wrap: balance;
}

.content-section h4 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
    text-wrap: balance;
}

.content-section h5 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
    text-wrap: balance;
}

.step-content {
    margin-top: var(--spacing-md);
}

/* 列表样式 */
.checklist {
    list-style: none;
    padding: 0;
}

.checklist li {
    padding: var(--spacing-sm) var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    background: var(--color-surface);
    border-radius: var(--radius-sm);
    border-left: 4px solid var(--color-success);
    transition: transform 0.2s ease;
}

.checklist li:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow-sm);
}

.content-section ol,
.content-section ul {
    margin-left: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.content-section ol li,
.content-section ul li {
    margin-bottom: var(--spacing-sm);
    line-height: 1.8;
}

/* 代码块样式 */
.code-block {
    position: relative;
    background: #1f2937;
    border-radius: var(--radius-md);
    margin: var(--spacing-md) 0;
    overflow: hidden;
}

.code-block .copy-btn {
    position: absolute;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    background: var(--color-primary);
    color: white;
    border: none;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: transform 0.2s ease, background-color 0.2s ease;
    z-index: var(--z-content);
}

.copy-btn:hover {
    background: var(--color-primary-dark);
    transform: translateY(-2px);
}

.copy-btn:active {
    transform: translateY(0);
}

.code-block pre {
    margin: 0;
    padding: var(--spacing-lg) var(--spacing-xl);
    overflow-x: auto;
    font-size: 0.9rem;
    line-height: 1.6;
    white-space: pre-wrap;
    word-break: break-word;
    overflow-wrap: anywhere;
}

.code-block code {
    color: #e5e7eb;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
}

/* 内联代码 */
code {
    background: transparent;
    color: white
    padding: 0.2rem 0.5rem;
    border-radius: var(--radius-sm);
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 0.9em;
    border: 1px solid #e5e7eb;
}

.content-section code {
    background: transparent;
    color: white
}

.code-block code {
    color: #e5e7eb;
    border: none;
}

/* 文件树样式 */
.file-tree {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin: var(--spacing-md) 0;
    overflow-x: auto;
}

.file-tree pre {
    margin: 0;
    font-size: 0.9rem;
    line-height: 1.6;
    color: var(--color-text);
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    white-space: pre;
    word-break: normal;
    overflow-wrap: normal;
}

.lesson-body pre {
    white-space: pre-wrap;
    word-break: break-word;
    overflow-wrap: anywhere;
}

/* 警告框样式 */
.warning-box {
    background: #FEF3C7;
    border-left: 4px solid var(--color-warning);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin: var(--spacing-lg) 0;
}

.warning-box p {
    margin: 0;
    color: var(--color-primary-dark);
    font-weight: 500;
}

.warning-box strong {
    color: var(--color-warning);
}

/* 课程链接样式 */
.lesson-links {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.lesson-link {
    display: block;
    padding: var(--spacing-md);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text);
    text-decoration: none;
    transition: transform 0.2s ease, color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
    font-weight: 500;
}

.lesson-link:hover {
    background: var(--color-secondary);
    border-color: var(--color-primary);
    color: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* 难度标签 */
.difficulty {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--color-secondary);
    color: var(--color-primary-dark);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
}

/* 链接样式 */
.lesson-body a,
.content-section a {
    color: var(--color-primary);
    text-decoration: none;
    border-bottom: 1px solid var(--color-primary-light);
    transition: color 0.2s ease, border-color 0.2s ease;
}

.lesson-body a:hover,
.content-section a:hover {
    color: var(--color-primary-dark);
    border-bottom-color: var(--color-primary-dark);
}

/* ==================== 返回顶部按钮 ==================== */
.back-to-top {
    position: fixed;
    bottom: calc(var(--spacing-xl) + env(safe-area-inset-bottom));
    right: calc(var(--spacing-xl) + env(safe-area-inset-right));
    width: 48px;
    height: 48px;
    background: var(--color-primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.2s ease, transform 0.2s ease;
    z-index: var(--z-floating);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--color-primary-dark);
    transform: translateY(-4px);
}

/* ==================== 滚动条样式 ==================== */
.sidebar::-webkit-scrollbar,
.content-area::-webkit-scrollbar {
    width: 6px;
}

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

.sidebar::-webkit-scrollbar-thumb,
.content-area::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 3px;
}

.sidebar::-webkit-scrollbar-thumb:hover,
.content-area::-webkit-scrollbar-thumb:hover {
    background: var(--color-primary-light);
}

/* ==================== 响应式设计 ==================== */
@media (max-width: 1024px) {
    .header-container {
        padding: var(--spacing-md) var(--spacing-lg);
    }

    .logo {
        width: 150px;
    }

    .site-title {
        font-size: 1.5rem;
    }

    .main-container {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
        top: 0;
        border-right: none;
        border-bottom: 1px solid var(--color-border);
        padding: var(--spacing-lg);
    }

    .course-list {
        display: grid;
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
        gap: var(--spacing-sm);
    }

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

@media (max-width: 768px) {
    .header-container {
        position: relative;
        justify-content: center;
        gap: var(--spacing-md);
        padding: 0.75rem var(--spacing-md);
    }

    .logo-section {
        flex-direction: row;
        gap: var(--spacing-sm);
        justify-content: center;
    }

    .logo {
        width: 40px;
        height: auto;
    }

    .site-title {
        display: none;
    }

    .nav-toggle {
        display: flex;
        position: absolute;
        left: var(--spacing-md);
    }

    .header-nav {
        position: absolute;
        right: var(--spacing-md);
    }

    .sidebar {
        position: fixed;
        top: 0;
        left: 0;
        height: 100svh;
        height: 100dvh;
        width: 82vw;
        max-width: 320px;
        padding: calc(var(--spacing-xl) + env(safe-area-inset-top)) var(--spacing-lg)
                 calc(var(--spacing-xl) + env(safe-area-inset-bottom));
        border-right: 1px solid var(--color-border);
        transform: translateX(-100%);
        transition: transform 0.25s ease;
        z-index: var(--z-sidebar);
        box-shadow: var(--shadow-lg);
    }

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

    .lesson-section h2 {
        font-size: 1.5rem;
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }

    .lesson-download-btn {
        width: 100%;
        margin-left: 0;
        justify-content: center;
    }

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

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

    .lesson-section h2 {
        font-size: 1.5rem;
    }

    .back-to-top {
        bottom: var(--spacing-lg);
        right: var(--spacing-lg);
        width: 40px;
        height: 40px;
    }
}

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

    .main-container {
        flex-direction: column;
    }

    .content-area {
        padding: 0;
    }

    .lesson-section {
        box-shadow: none;
        border: 1px solid var(--color-border);
        page-break-inside: avoid;
    }
}

/* ==================== 深色模式支持 ==================== */
@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #1a1612;
        --color-surface: #24201a;
        --color-text: #F9FAFB;
        --color-text-secondary: #9CA3AF;
        --color-border: #374151;
        --color-secondary: #453a2a;
    }
}

/* ==================== Modal 弹窗样式 ==================== */
.modal {
    display: none;
    position: fixed;
    z-index: var(--z-modal);
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.6);
    padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom)
             env(safe-area-inset-left);
    box-sizing: border-box;
}

.modal-content {
    background-color: var(--color-surface);
    margin: 10% auto;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 600px;
    box-shadow: var(--shadow-lg);
    position: relative;
}

.modal-close {
    position: absolute;
    right: var(--spacing-lg);
    top: var(--spacing-lg);
    font-size: 28px;
    font-weight: bold;
    color: var(--color-text);
    cursor: pointer;
    line-height: 1;
    transition: color 0.2s ease;
}

.modal-close:hover {
    color: var(--color-danger);
}

.modal-title {
    margin: 0 0 var(--spacing-md) 0;
    color: var(--color-text);
    font-size: 1.125rem;
    font-weight: 700;
}

.modal-body {
    max-height: 60vh;
    overflow-y: auto;
    word-wrap: break-word;
    overflow-wrap: break-word;
}

.download-item {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    transition: box-shadow 0.3s ease;
}

.download-item:hover {
    box-shadow: var(--shadow-md);
}

.download-item-title {
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.875rem;
}

.download-item-title svg {
    color: var(--color-primary);
    width: 16px;
    height: 16px;
}

.download-link {
    display: inline-block;
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
    transition: color 0.2s ease;
    word-break: break-all;
    font-size: 0.813rem;
}

.download-link:hover {
    color: var(--color-primary-dark);
    text-decoration: underline;
}

.download-code {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-xs);
}

.download-code-box {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    padding: var(--spacing-xs) var(--spacing-sm);
    font-family: 'Courier New', monospace;
    font-weight: 600;
    color: var(--color-primary-dark);
    font-size: 0.813rem;
}

.code-block .copy-btn {
    background: var(--color-primary);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    padding: var(--spacing-xs) var(--spacing-md);
    cursor: pointer;
    font-size: 0.875rem;
    font-weight: 600;
    transition: background 0.2s ease;
}

.copy-btn:hover {
    background: var(--color-primary-dark);
}

.copy-btn.copied {
    background: var(--color-success);
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* 移动端适配 */
@media (max-width: 768px) {
    .modal-content {
        width: 95%;
        margin: 5% auto;
        padding: var(--spacing-lg);
    }

    .modal-title {
        font-size: 1.25rem;
    }

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

/* ==================== 前言展示区 ==================== */
.hero-section {
    margin-bottom: var(--spacing-2xl);
    padding-bottom: var(--spacing-2xl);
    border-bottom: 1px solid var(--color-border);
}

.hero-intro {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

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

.hero-desc {
    font-size: 1.1rem;
    color: var(--color-text-secondary);
    line-height: 1.8;
}

.hero-desc strong {
    color: var(--color-primary);
}

.showcase-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.showcase-card {
    background: linear-gradient(135deg, #1e3a5f 0%, #0f172a 100%);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.showcase-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.showcase-image {
    width: 100%;
    height: 180px;
    overflow: hidden;
    background: #0a0a14;
}

.showcase-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.showcase-card:hover .showcase-image img {
    transform: scale(1.05);
}

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

.showcase-tag {
    display: inline-block;
    padding: 5px 14px;
    background: linear-gradient(135deg, #3b82f6, #06b6d4);
    color: white;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 20px;
    margin-bottom: var(--spacing-sm);
    text-shadow: 0 1px 2px rgba(0,0,0,0.2);
}

.showcase-content h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: #ffffff;
    margin-bottom: var(--spacing-sm);
}

.showcase-content p {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.75);
    line-height: 1.7;
}

@media (max-width: 1024px) {
    .showcase-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }

    .showcase-card {
        display: flex;
        flex-direction: row;
    }

    .showcase-image {
        width: 200px;
        height: auto;
        min-height: 150px;
        flex-shrink: 0;
    }

    .hero-title {
        font-size: 1.5rem;
    }
}

@media (max-width: 640px) {
    .showcase-card {
        flex-direction: column;
    }

    .showcase-image {
        width: 100%;
        height: 160px;
    }
}