:root {
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-tertiary: #94a3b8;
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f1f5f9;
    --border-color: #e2e8f0;
    --accent: #06b6d4;
    --shadow-color: rgba(0, 0, 0, 0.1);
}
[data-theme="dark"] {
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-tertiary: #94a3b8;
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --border-color: #334155;
    --accent: #06b6d4;
    --shadow-color: rgba(0, 0, 0, 0.3);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.8;
    color: var(--text-primary);
    background: var(--bg-primary);
    padding: 20px;
}
.article-container {
    max-width: 720px;
    margin: 0 auto;
    background: var(--bg-secondary);
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 4px 6px var(--shadow-color);
}
.article-container h1 { font-size: 2rem; margin-bottom: 0.5rem; border-bottom: 3px solid var(--accent); padding-bottom: 15px; }
.article-container h2 { font-size: 1.35rem; margin-top: 2rem; margin-bottom: 0.75rem; }
.article-container h3 { font-size: 1.15rem; margin-top: 1.5rem; margin-bottom: 0.5rem; }
.article-container p { margin-bottom: 1rem; color: var(--text-secondary); }
.article-container ul { margin-left: 1.5rem; margin-bottom: 1rem; color: var(--text-secondary); }
.article-container li { margin-bottom: 0.5rem; }
.back-link { display: inline-block; margin-bottom: 1.5rem; color: var(--accent); font-weight: 600; text-decoration: none; }
.back-link:hover { text-decoration: underline; }
.meta { font-size: 0.875rem; color: var(--text-tertiary); margin-bottom: 1.5rem; }