:root{--primary:#1a1a2e;--accent:#00d9ff;--bg:#fafafa;--bg-dark:#0f0f23;--text:#1a1a2e;--text-light:#666;--border:#e0e0e0;--card-bg:#fff}@media (prefers-color-scheme:dark){:root{--bg:#0f0f23;--text:#e0e0e0;--text-light:#999;--border:#333;--card-bg:#1a1a2e}}*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Hiragino Sans GB,Microsoft YaHei,sans-serif;background:var(--bg);color:var(--text);line-height:1.6}.container{max-width:900px;margin:0 auto;padding:2rem;min-height:calc(100vh - 140px)}.nav{background:var(--card-bg);border-bottom:1px solid var(--border);padding:1rem 2rem;display:flex;justify-content:space-between;align-items:center;position:-webkit-sticky;position:sticky;top:0;z-index:100}.logo{font-size:1.25rem;font-weight:600;color:var(--text)}.logo,.nav-links a{text-decoration:none}.nav-links a{margin-left:2rem;color:var(--text-light)}.nav-links a:hover{color:var(--accent)}.footer{text-align:center;padding:2rem;color:var(--text-light);font-size:.875rem;border-top:1px solid var(--border)}.card{background:var(--card-bg);border:1px solid var(--border);border-radius:8px;padding:1.5rem;margin-bottom:1rem;transition:box-shadow .2s}.card:hover{box-shadow:0 4px 12px rgba(0,0,0,.1)}.card h2{font-size:1.25rem;margin-bottom:.5rem}.card h2 a{color:var(--text);text-decoration:none}.card h2 a:hover{color:var(--accent)}.card p{color:var(--text-light);font-size:.9rem}.categories{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));grid-gap:1.5rem;gap:1.5rem;margin:2rem 0}.category-card{background:var(--card-bg);border:1px solid var(--border);border-radius:12px;padding:2rem;text-align:center;text-decoration:none;color:var(--text);transition:all .2s}.category-card:hover{border-color:var(--accent);transform:translateY(-2px);box-shadow:0 8px 24px rgba(0,217,255,.1)}.category-icon{font-size:3rem;margin-bottom:1rem}.category-name{font-size:1.25rem;font-weight:600;margin-bottom:.5rem}.category-count{color:var(--text-light);font-size:.875rem}.article-header{margin-bottom:2rem;padding-bottom:1.5rem;border-bottom:1px solid var(--border)}.article-header h1{font-size:2rem;margin-bottom:1rem}.article-meta{color:var(--text-light);font-size:.875rem}.article-meta span{margin-right:1.5rem}.article-content{font-size:1rem;line-height:1.8}.article-content h1,.article-content h2,.article-content h3{margin-top:2rem;margin-bottom:1rem}.article-content h2{font-size:1.5rem;border-bottom:1px solid var(--border);padding-bottom:.5rem}.article-content h3{font-size:1.25rem}.article-content p{margin-bottom:1rem}.article-content code{background:rgba(0,217,255,.1);padding:.2rem .4rem;border-radius:4px;font-size:.9em}.article-content pre{background:var(--primary);color:#e0e0e0;padding:1rem;border-radius:8px;overflow-x:auto;margin:1rem 0}.article-content pre code{background:none;padding:0}.article-content table{width:100%;border-collapse:collapse;margin:1rem 0}.article-content td,.article-content th{border:1px solid var(--border);padding:.75rem;text-align:left}.article-content th{background:rgba(0,217,255,.05)}.article-content blockquote{border-left:4px solid var(--accent);padding-left:1rem;margin:1rem 0;color:var(--text-light)}.tags{display:flex;flex-wrap:wrap;gap:.5rem;margin-top:1rem}.tag{background:rgba(0,217,255,.1);color:var(--accent);padding:.25rem .75rem;border-radius:100px;font-size:.8rem}.search-box{display:flex;gap:1rem;margin-bottom:2rem}.search-box input{flex:1 1;padding:.75rem 1rem;border:1px solid var(--border);border-radius:8px;font-size:1rem;background:var(--card-bg);color:var(--text)}.search-box button{padding:.75rem 2rem;background:var(--primary);color:#fff;border:none;border-radius:8px;cursor:pointer}.search-highlight{background:rgba(0,217,255,.2);padding:0 .2rem}.graph-container{background:var(--card-bg);border:1px solid var(--border);border-radius:8px;padding:1.5rem;min-height:500px}