/* ===== CSS 变量 ===== */
:root {
    /* 颜色系统 - 浅色主题 */
    --c-bg: #ffffff;
    --c-bg-soft: #f9fafb;
    --c-bg-mute: #f3f4f6;
    --c-bg-alt: #e5e7eb;
    
    --c-text: #1f2937;
    --c-text-light: #4b5563;
    --c-text-lighter: #6b7280;
    --c-text-mute: #9ca3af;
    
    --c-brand: #3b82f6;
    --c-brand-light: #60a5fa;
    --c-brand-dark: #2563eb;
    
    --c-border: #e5e7eb;
    --c-border-light: #f3f4f6;
    
    --c-divider: #e5e7eb;
    
    /* 侧边栏 */
    --sidebar-width: 300px;
    --sidebar-bg: var(--c-bg);
    
    /* 顶栏 */
    --header-height: 64px;
    --header-bg: var(--c-bg);
    
    /* 阴影 */
    --shadow-1: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-2: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-3: 0 12px 32px rgba(0, 0, 0, 0.12);
    
    /* 圆角 */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    
    /* 过渡 */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
}

/* 深色主题 */
[data-theme="dark"] {
    --c-bg: #0f172a;
    --c-bg-soft: #1e293b;
    --c-bg-mute: #334155;
    --c-bg-alt: #475569;
    
    --c-text: #f1f5f9;
    --c-text-light: #cbd5e1;
    --c-text-lighter: #94a3b8;
    --c-text-mute: #64748b;
    
    --c-brand: #60a5fa;
    --c-brand-light: #93c5fd;
    --c-brand-dark: #3b82f6;
    
    --c-border: #334155;
    --c-border-light: #1e293b;
    
    --c-divider: #334155;
    
    --sidebar-bg: #0f172a;
    --header-bg: #0f172a;
}

/* ===== 重置样式 ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 16px;
    line-height: 1.8;
    color: var(--c-text);
    background: var(--c-bg);
    min-height: 100vh;
}

a {
    color: inherit;
    text-decoration: none;
}

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

/* ===== 顶部导航栏 ===== */
.top-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--header-bg);
    border-bottom: 1px solid var(--c-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    z-index: 100;
    backdrop-filter: blur(8px);
}

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

.sidebar-toggle {
    display: none;
    padding: 8px;
    color: var(--c-text-light);
    border-radius: var(--radius-sm);
    transition: var(--transition-fast);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 700;
    font-size: 22px;
    color: var(--c-text);
    transition: var(--transition-fast);
}

.logo:hover {
    color: var(--c-brand);
}


.header-center {
    flex: 1;
    max-width: 480px;
    margin: 0 40px;
}

.search-wrapper {
    position: relative;
    display: flex;
    align-items: center;
    background: var(--c-bg-soft);
    border: 1px solid var(--c-border);
    border-radius: var(--radius-lg);
    padding: 0 12px;
    transition: var(--transition-fast);
}

.search-wrapper:focus-within {
    border-color: var(--c-brand);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.search-icon {
    color: var(--c-text-mute);
    flex-shrink: 0;
}

.search-wrapper input {
    flex: 1;
    border: none;
    background: none;
    padding: 12px 14px;
    font-size: 16px;
    color: var(--c-text);
    outline: none;
}

.search-wrapper input::placeholder {
    color: var(--c-text-mute);
}

.search-kbd {
    display: inline-flex;
    align-items: center;
    padding: 4px 8px;
    font-size: 12px;
    font-family: inherit;
    color: var(--c-text-mute);
    background: var(--c-bg);
    border: 1px solid var(--c-border);
    border-radius: var(--radius-sm);
}

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

.theme-toggle {
    padding: 8px;
    color: var(--c-text-light);
    border-radius: var(--radius-sm);
    transition: var(--transition-fast);
}

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

.theme-toggle .moon-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle .sun-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle .moon-icon {
    display: block;
}

.header-right .nav-link {
    font-size: 13px;
    color: var(--c-text-lighter);
    transition: var(--transition-fast);
}

.header-right .nav-link:hover {
    color: var(--c-brand);
}

/* ===== 布局 ===== */
.layout {
    display: flex;
    padding-top: var(--header-height);
    min-height: 100vh;
}

/* ===== 侧边栏 ===== */
.sidebar {
    position: fixed;
    top: var(--header-height);
    left: 0;
    bottom: 0;
    width: var(--sidebar-width);
    background: var(--sidebar-bg);
    border-right: 1px solid var(--c-border);
    overflow-y: auto;
    overflow-x: hidden;
    z-index: 50;
    transition: transform var(--transition-normal);
}

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

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

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

.sidebar::-webkit-scrollbar-thumb:hover {
    background: var(--c-text-mute);
}

.sidebar-nav {
    padding: 16px 0;
}

/* 导航组 */
.nav-group {
    margin-bottom: 4px;
}

.nav-group-title {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 24px;
    font-size: 16px;
    font-weight: 600;
    color: var(--c-text);
    cursor: pointer;
    user-select: none;
    transition: var(--transition-fast);
}

.nav-group-title:hover {
    background: var(--c-bg-soft);
}

.nav-group-title .chevron {
    transition: transform var(--transition-fast);
    color: var(--c-text-mute);
}

.nav-group-title.expanded .chevron {
    transform: rotate(90deg);
}

.nav-group-items {
    display: none;
    padding-left: 8px;
}

.nav-group-items.expanded {
    display: block;
}

/* 子导航组 */
.nav-subgroup {
    margin-bottom: 2px;
}

.nav-subgroup-title {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px 12px 36px;
    font-size: 15px;
    font-weight: 500;
    color: var(--c-text-light);
    cursor: pointer;
    user-select: none;
    transition: var(--transition-fast);
}

.nav-subgroup-title:hover {
    color: var(--c-text);
    background: var(--c-bg-soft);
}

.nav-subgroup-title .chevron {
    transition: transform var(--transition-fast);
    color: var(--c-text-mute);
}

.nav-subgroup-title.expanded .chevron {
    transform: rotate(90deg);
}

.nav-subgroup-items {
    display: none;
}

.nav-subgroup-items.expanded {
    display: block;
}

/* 导航链接 */
.sidebar-nav .nav-link {
    display: block;
    padding: 10px 24px 10px 56px;
    font-size: 15px;
    color: var(--c-text-lighter);
    border-left: 3px solid transparent;
    transition: var(--transition-fast);
}

.sidebar-nav .nav-link:hover {
    color: var(--c-text);
    background: var(--c-bg-soft);
}

.sidebar-nav .nav-link.active {
    color: var(--c-brand);
    background: rgba(59, 130, 246, 0.08);
    border-left-color: var(--c-brand);
}

/* 直接在 nav-group-items 下的 nav-link */
.nav-group-items > .nav-link {
    padding-left: 44px;
}

/* ===== 主内容区域 ===== */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    min-height: calc(100vh - var(--header-height));
    padding: 48px 64px;
    max-width: 960px;
}

/* ===== 首页 ===== */
.home-content {
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.hero {
    text-align: center;
    padding: 80px 0 60px;
}

.hero h1 {
    font-size: 52px;
    font-weight: 700;
    color: var(--c-text);
    margin-bottom: 20px;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 24px;
    color: var(--c-text-light);
    margin-bottom: 12px;
}

.hero-desc {
    font-size: 18px;
    color: var(--c-text-mute);
}

/* 特性卡片 */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
    margin-bottom: 60px;
}

.feature-card {
    background: var(--c-bg-soft);
    border: 1px solid var(--c-border);
    border-radius: var(--radius-lg);
    padding: 32px;
    cursor: pointer;
    transition: var(--transition-normal);
}

.feature-card:hover {
    border-color: var(--c-brand);
    box-shadow: var(--shadow-2);
    transform: translateY(-3px);
}


.feature-card h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--c-text);
    margin-bottom: 12px;
}

.feature-card p {
    font-size: 16px;
    color: var(--c-text-lighter);
    line-height: 1.7;
}

/* 快速开始 */
.quick-start {
    margin-top: 48px;
}

.quick-start h2 {
    font-size: 24px;
    font-weight: 600;
    color: var(--c-text);
    margin-bottom: 24px;
}

.quick-links {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 16px;
}

.quick-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 18px 24px;
    background: var(--c-bg);
    border: 1px solid var(--c-border);
    border-radius: var(--radius-md);
    font-size: 16px;
    color: var(--c-text-light);
    transition: var(--transition-fast);
}

.quick-link:hover {
    border-color: var(--c-brand);
    color: var(--c-brand);
    background: rgba(59, 130, 246, 0.04);
}


/* ===== 文章内容 ===== */
.article-content {
    animation: fadeIn 0.3s ease;
}

.article-header {
    margin-bottom: 40px;
    padding-bottom: 32px;
    border-bottom: 1px solid var(--c-border);
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 15px;
    color: var(--c-text-mute);
    margin-bottom: 20px;
}

.breadcrumb a {
    color: var(--c-text-lighter);
    transition: var(--transition-fast);
}

.breadcrumb a:hover {
    color: var(--c-brand);
}

.breadcrumb .separator {
    color: var(--c-text-mute);
}

.article-header h1 {
    font-size: 40px;
    font-weight: 700;
    color: var(--c-text);
    line-height: 1.3;
}

.article-body {
    font-size: 18px;
    line-height: 1.9;
    color: var(--c-text-light);
}

.article-body h2 {
    font-size: 28px;
    font-weight: 600;
    color: var(--c-text);
    margin: 48px 0 24px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--c-border);
}

.article-body h3 {
    font-size: 22px;
    font-weight: 600;
    color: var(--c-text);
    margin: 32px 0 16px;
}

.article-body p {
    margin-bottom: 20px;
}

.article-body ul, .article-body ol {
    margin: 20px 0;
    padding-left: 28px;
}

.article-body li {
    margin-bottom: 12px;
}

.article-body strong {
    color: var(--c-text);
    font-weight: 600;
}

.article-body code {
    background: var(--c-bg-mute);
    padding: 3px 8px;
    border-radius: var(--radius-sm);
    font-size: 16px;
    font-family: 'SF Mono', 'Fira Code', Consolas, monospace;
}

/* 内容块 */
.content-block {
    background: var(--c-bg-soft);
    border-left: 4px solid var(--c-brand);
    padding: 24px 32px;
    margin: 28px 0;
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.content-block h4 {
    font-size: 18px;
    font-weight: 600;
    color: var(--c-text);
    margin-bottom: 14px;
}

.content-block p {
    font-size: 17px;
    margin-bottom: 0;
}

/* 文章底部 */
.article-footer {
    margin-top: 60px;
    padding-top: 32px;
    border-top: 1px solid var(--c-border);
}

.article-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 20px;
}

.article-tag {
    display: inline-block;
    padding: 6px 16px;
    background: var(--c-bg-mute);
    color: var(--c-text-lighter);
    border-radius: 100px;
    font-size: 14px;
    font-weight: 500;
    transition: var(--transition-fast);
}

.article-tag:hover {
    background: var(--c-brand);
    color: white;
}

.article-meta {
    font-size: 15px;
    color: var(--c-text-mute);
}

/* 文章导航 */
.article-nav {
    display: flex;
    justify-content: space-between;
    gap: 20px;
    margin-top: 48px;
    padding-top: 24px;
    border-top: 1px solid var(--c-border);
}

.nav-prev, .nav-next {
    flex: 1;
    padding: 16px 20px;
    background: var(--c-bg-soft);
    border: 1px solid var(--c-border);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
}

.nav-prev:hover, .nav-next:hover {
    border-color: var(--c-brand);
}

.nav-label {
    display: block;
    font-size: 12px;
    color: var(--c-text-mute);
    margin-bottom: 4px;
}

.nav-title {
    font-size: 14px;
    font-weight: 500;
    color: var(--c-text);
}

.nav-next {
    text-align: right;
}

/* ===== 搜索结果 ===== */
.search-results h2 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 24px;
}

.results-list {
    display: flex;
        flex-direction: column;
    gap: 16px;
}

.result-item {
    padding: 20px;
    background: var(--c-bg-soft);
    border: 1px solid var(--c-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition-fast);
}

.result-item:hover {
    border-color: var(--c-brand);
    box-shadow: var(--shadow-1);
}

.result-category {
    display: inline-block;
    padding: 2px 8px;
    background: var(--c-brand);
    color: white;
    border-radius: 100px;
    font-size: 11px;
    font-weight: 500;
    margin-bottom: 8px;
}

.result-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--c-text);
    margin-bottom: 8px;
}

.result-excerpt {
    font-size: 14px;
    color: var(--c-text-lighter);
    line-height: 1.6;
}

/* ===== 搜索弹窗 ===== */
.search-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    align-items: flex-start;
    justify-content: center;
    padding-top: 100px;
    z-index: 1000;
}

.search-modal.active {
    display: flex;
}

.search-modal-content {
    width: 100%;
    max-width: 560px;
    background: var(--c-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-3);
    overflow: hidden;
}

.search-modal-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 20px;
    border-bottom: 1px solid var(--c-border);
}

.search-modal-header svg {
    color: var(--c-text-mute);
    flex-shrink: 0;
}

.search-modal-header input {
    flex: 1;
    border: none;
    background: none;
    font-size: 16px;
    color: var(--c-text);
    outline: none;
}

.search-modal-header input::placeholder {
    color: var(--c-text-mute);
}

.search-modal-header kbd {
    padding: 4px 8px;
    font-size: 12px;
    color: var(--c-text-mute);
    background: var(--c-bg-mute);
    border-radius: var(--radius-sm);
}

.search-modal-results {
    max-height: 400px;
    overflow-y: auto;
    padding: 8px;
}

.modal-result-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition-fast);
}

.modal-result-item:hover {
    background: var(--c-bg-soft);
}

.modal-result-icon {
    font-size: 18px;
}

.modal-result-text {
    flex: 1;
}

.modal-result-title {
    font-size: 14px;
    font-weight: 500;
    color: var(--c-text);
}

.modal-result-path {
    font-size: 12px;
    color: var(--c-text-mute);
}

/* ===== 响应式设计 ===== */
@media (max-width: 1024px) {
    .main-content {
        padding: 32px 40px;
    }
}

@media (max-width: 768px) {
    .sidebar-toggle {
        display: flex;
    }
    
    .sidebar {
        transform: translateX(-100%);
    }
    
    .sidebar.open {
        transform: translateX(0);
        box-shadow: var(--shadow-3);
    }
    
    .main-content {
        margin-left: 0;
        padding: 24px;
    }
    
    .header-center {
        display: none;
    }
    
    .hero h1 {
        font-size: 36px;
    }
    
    .hero-subtitle {
        font-size: 20px;
    }
    
    .features {
        grid-template-columns: 1fr;
    }
    
    .quick-links {
        grid-template-columns: 1fr;
    }
    
    .article-header h1 {
        font-size: 30px;
    }
    
    .article-body {
        font-size: 17px;
    }
    
    .article-nav {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .top-header {
        padding: 0 16px;
    }
    
    .logo-text {
        display: none;
    }
    
    .hero {
        padding: 48px 0 40px;
    }
    
    .hero h1 {
        font-size: 32px;
    }
    
    .feature-card {
        padding: 24px;
    }
    
    .article-header h1 {
        font-size: 26px;
    }
}

/* ===== 工具提示 ===== */
.tooltip {
    position: relative;
}

.tooltip::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%);
    padding: 6px 12px;
    background: var(--c-text);
    color: var(--c-bg);
    font-size: 12px;
    border-radius: var(--radius-sm);
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: var(--transition-fast);
}

.tooltip:hover::after {
    opacity: 1;
}

/* ===== 移动端侧边栏遮罩 ===== */
.sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 40;
    display: none;
}

.sidebar-overlay.active {
    display: block;
}

/* ===== 打印样式 ===== */
@media print {
    .top-header,
    .sidebar,
    .article-nav {
        display: none;
    }
    
    .main-content {
        margin: 0;
        padding: 20px;
    }
}