:root {
    --primary-color: #2563eb;       /* 主色调：现代科技蓝 */
    --primary-hover: #1d4ed8;
    --bg-color: #f8fafc;            /* 页面浅灰背景 */
    --card-bg: #ffffff;             /* 卡片纯白背景 */
    --text-main: #1e293b;           /* 主要文字颜色 */
    --text-secondary: #64748b;      /* 次要文字颜色（日期、摘要） */
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius: 8px;

    --color-primary: #1e4a8c;
    --color-primary-dark: #153a70;
    --color-primary-light: #e8f0fb;

    /* Accent */
    --color-accent: #e67e22;
    --color-accent-light: #fef3e6;

    /* Success / Risk */
    --color-success: #2e8b57;
    --color-danger: #c0392b;

    /* Neutrals - Warm Gray */
    --color-bg: #fafaf9;
    --color-bg-elevated: #ffffff;
    --color-bg-subtle: #f5f5f3;
    --color-border: #e8e7e3;
    --color-border-strong: #d4d3ce;
    --color-text: #1f2328;
    --color-text-secondary: #57606a;
    --color-text-tertiary: #8b949e;

    /* Typography */
    --font-family-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", "Source Han Sans SC", sans-serif;
    --font-family-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", Georgia, serif;

    /* Spacing Scale */
    --space-1: 4px;
    --space-2: 8px;
    --space-3: 12px;
    --space-4: 16px;
    --space-5: 20px;
    --space-6: 24px;
    --space-8: 32px;
    --space-10: 40px;
    --space-12: 48px;
    --space-16: 64px;

    /* Radii */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 2px 8px rgba(0,0,0,0.06);
    --shadow-lg: 0 4px 16px rgba(0,0,0,0.08);

    /* Layout */
    --max-width-content: 720px;
    --max-width-page: 1200px;
    --toc-width: 220px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Microsoft YaHei", sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
}
a { text-decoration: none; color: inherit; transition: color 0.2s; }
a:hover { color: var(--primary-color); }

/* ================= 2. 布局容器 ================= */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    margin-top: 60px;
}

/* 移动端适配 */
@media (max-width: 768px) {
    .container { grid-template-columns: 1fr; }
}

/* ================= 3. 面包屑导航 (SEO & UX) ================= */
.breadcrumb {
    grid-column: 1 / -1;
    padding: 10px 0;
    font-size: 14px;
    color: var(--text-secondary);
}
.breadcrumb a:hover { color: var(--primary-color); }
.breadcrumb span { margin: 0 8px; color: #cbd5e1; }

.article-layout {
    margin-top: 20px;
}

.article-main {
    min-width: 0;
}

/* Article Header */
.article-header {
    margin-bottom: var(--space-10);
}

.article-category-tag {
    display: inline-block;
    padding: 4px 12px;
    background-color: var(--color-primary-light);
    color: var(--color-primary);
    font-size: 13px;
    font-weight: 500;
    border-radius: 100px;
    margin-bottom: var(--space-5);
}

.article-header h1 {
    font-size: clamp(24px, 4vw, 32px);
    line-height: 1.35;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--space-5);
    letter-spacing: -0.01em;
}

.article-meta {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--space-4);
    font-size: 14px;
    color: var(--color-text-tertiary);
    margin-bottom: var(--space-5);
}

.article-meta .meta-item {
    display: flex;
    align-items: center;
    gap: var(--space-1);
}

.article-meta .dot {
    width: 3px;
    height: 3px;
    border-radius: 50%;
    background-color: var(--color-border-strong);
}

.article-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}

.article-tags .tag {
    display: inline-flex;
    align-items: center;
    gap: 2px;
    padding: 4px 10px;
    background-color: var(--color-bg-subtle);
    color: var(--color-text-secondary);
    font-size: 13px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-border);
}

.article-tags .tag::before {
    content: "#";
    color: var(--color-text-tertiary);
}

/* ============================================
   Article Content
   ============================================ */
.article-content {
    font-size: 16px;
    line-height: 1.85;
    color: var(--color-text);
}

.article-content p {
    margin-bottom: var(--space-5);
}

.article-content h2 {
    font-size: 22px;
    font-weight: 700;
    line-height: 1.4;
    color: var(--color-text);
    margin-top: var(--space-10);
    margin-bottom: var(--space-5);
    padding-left: var(--space-4);
    border-left: 4px solid var(--color-primary);
    scroll-margin-top: 84px;
}

.article-content h3 {
    font-size: 18px;
    font-weight: 600;
    line-height: 1.5;
    color: var(--color-text);
    margin-top: var(--space-8);
    margin-bottom: var(--space-4);
    scroll-margin-top: 84px;
}

.article-content ul,
.article-content ol {
    margin-bottom: var(--space-5);
    padding-left: var(--space-6);
}

.article-content li {
    margin-bottom: var(--space-2);
}

.article-content li::marker {
    color: var(--color-text-tertiary);
}

/* Checklist style - signature element */
.checklist {
    list-style: none;
    padding-left: 0 !important;
    margin-bottom: var(--space-6) !important;
}

.checklist li {
    position: relative;
    padding-left: 32px;
    margin-bottom: var(--space-3) !important;
    line-height: 1.75;
}

.checklist li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 6px;
    width: 20px;
    height: 20px;
    border: 2px solid var(--color-border-strong);
    border-radius: 3px;
    background-color: var(--color-bg-elevated);
}

.checklist li::after {
    content: "";
    position: absolute;
    left: 5px;
    top: 10px;
    width: 10px;
    height: 6px;
    border-left: 2px solid var(--color-success);
    border-bottom: 2px solid var(--color-success);
    transform: rotate(-45deg);
    opacity: 0.6;
}

/* Note box */
.note-box {
    background-color: var(--color-accent-light);
    border-left: 4px solid var(--color-accent);
    padding: var(--space-4) var(--space-5);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    margin: var(--space-6) 0;
    font-size: 15px;
}

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

/* Warning box */
.warning-box {
    background-color: #fef2f2;
    border-left: 4px solid var(--color-danger);
    padding: var(--space-4) var(--space-5);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    margin: var(--space-6) 0;
    font-size: 15px;
}

/* Step list */
.step-list {
    list-style: none;
    padding-left: 0 !important;
    margin-bottom: var(--space-6) !important;
    counter-reset: step-counter;
}

.step-list li {
    position: relative;
    padding-left: 44px;
    margin-bottom: var(--space-4) !important;
    counter-increment: step-counter;
}

.step-list li::before {
    content: counter(step-counter);
    position: absolute;
    left: 0;
    top: 2px;
    width: 28px;
    height: 28px;
    background-color: var(--color-primary);
    color: #fff;
    font-size: 14px;
    font-weight: 600;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Inline code */
.article-content code {
    background-color: var(--color-bg-subtle);
    padding: 2px 6px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-family: "SF Mono", Menlo, Monaco, Consolas, monospace;
    border: 1px solid var(--color-border);
}

/* Divider */
.article-content hr {
    border: none;
    border-top: 1px solid var(--color-border);
    margin: var(--space-10) 0;
}

/* Strong text */
.article-content strong {
    font-weight: 600;
}

/* ============================================
   CTA Card (End of Article)
   ============================================ */
.cta-card {
    margin: var(--space-12) 0;
    padding: var(--space-8);
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    border-radius: var(--radius-lg);
    color: #fff;
    position: relative;
    overflow: hidden;
}

.cta-card::before {
    content: "";
    position: absolute;
    top: -50%;
    right: -10%;
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    border-radius: 50%;
}

.cta-card-content {
    position: relative;
    z-index: 1;
}

.cta-card h3 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: var(--space-3);
    color: #fff;
    border: none;
    padding: 0;
}

.cta-card p {
    font-size: 15px;
    line-height: 1.75;
    opacity: 0.9;
    margin-bottom: var(--space-6);
}

.cta-card .btn-accent {
    background-color: var(--color-accent);
    color: #fff;
    border-color: var(--color-accent);
    padding: 14px 28px;
    font-size: 16px;
}

.cta-card .btn-accent:hover {
    background-color: #d66f14;
    border-color: #d66f14;
}

.cta-card .btn-arrow {
    transition: transform 0.2s ease;
}

.cta-card .btn-accent:hover .btn-arrow {
    transform: translateX(2px);
}

/* ============================================
   Related Articles
   ============================================ */
.related-section {
    margin-top: var(--space-12);
    padding-top: var(--space-10);
    border-top: 1px solid var(--color-border);
}

.related-section h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: var(--space-6);
    color: var(--color-text);
}

.related-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--space-5);
}

.related-card {
    background-color: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--space-5);
    transition: all 0.2s ease;
    display: block;
}

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

.related-card .related-tag {
    display: inline-block;
    font-size: 12px;
    color: var(--color-primary);
    background-color: var(--color-primary-light);
    padding: 2px 8px;
    border-radius: 4px;
    margin-bottom: var(--space-3);
    font-weight: 500;
}

.related-card h4 {
    font-size: 15px;
    font-weight: 600;
    line-height: 1.5;
    color: var(--color-text);
    margin-bottom: var(--space-2);
}

.related-card p {
    font-size: 13px;
    line-height: 1.6;
    color: var(--color-text-secondary);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

th, td {
    border: 1px solid #ddd; /* 添加边框 */
    padding: 8px;
    text-align: left;
}

th {
    font-weight: bold;
}