:root{
  --bg:#f6f8fc;
  --surface:#ffffff;
  --ink:#0f172a;
  --muted:#5d6b82;
  --line:#e3e8f1;
  --accent:#1f5aff;
  --accent-deep:#0b3fd4;
  --accent-soft:#edf3ff;
  --dark:#0b1220;
  --mono:"SF Mono","JetBrains Mono",Menlo,Consolas,"Liberation Mono",monospace;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans SC",sans-serif;
  background:var(--bg);
  color:var(--ink);
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}
::selection{background:rgba(31,90,255,.18)}
.wrap{max-width:880px;margin:0 auto;padding:0 24px}

/* ===== 顶部导航 ===== */
.nav{position:sticky;top:0;z-index:10;background:rgba(246,248,252,.88);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:60px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700}
.brand-mark{
  width:30px;height:30px;border-radius:8px;display:grid;place-items:center;
  background:linear-gradient(135deg,var(--accent),var(--accent-deep));
  color:#fff;font-size:15px;font-weight:700;
  box-shadow:0 4px 12px rgba(31,90,255,.28);
}
.brand-name{font-size:16px;letter-spacing:.5px}
.nav-links{display:flex;gap:26px;font-size:14px;color:var(--muted)}
.nav-links a:hover{color:var(--accent)}

/* ===== 内容区块 ===== */
.section{padding:64px 0}
.section:first-child{padding-top:56px}
.section + .section{border-top:1px solid var(--line)}
.section-head{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:28px}
.section-title{font-size:24px;font-weight:700;letter-spacing:1px}
.section-title::before{content:"# ";color:var(--accent);font-family:var(--mono);font-weight:400}

/* 笔记列表 */
.note-list{list-style:none;display:flex;flex-direction:column;gap:14px}
.note{
  display:flex;gap:22px;align-items:flex-start;
  background:var(--surface);border:1px solid var(--line);border-radius:14px;
  padding:20px 22px;transition:border-color .2s,box-shadow .2s,transform .2s;
}
.note:hover{border-color:#c6d6ff;box-shadow:0 8px 24px rgba(15,23,42,.06);transform:translateY(-1px)}
.note time{font-family:var(--mono);font-size:12.5px;color:var(--muted);padding-top:3px;white-space:nowrap}
.note-tag{
  display:inline-block;font-size:12px;color:var(--accent-deep);background:var(--accent-soft);
  border-radius:6px;padding:2px 9px;margin-bottom:8px;
}
.note h3{font-size:16.5px;font-weight:600;line-height:1.5}
.note h3 a:hover{color:var(--accent)}
.note p{margin-top:6px;font-size:13.5px;color:var(--muted)}

/* 分类卡片 */
.topic-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:14px}
.topic{
  background:var(--surface);border:1px solid var(--line);border-radius:14px;
  padding:20px;transition:border-color .2s,box-shadow .2s,transform .2s;
}
.topic:hover{border-color:#c6d6ff;box-shadow:0 8px 24px rgba(15,23,42,.06);transform:translateY(-1px)}
.topic-icon{font-family:var(--mono);font-size:18px;color:var(--accent);margin-bottom:12px}
.topic h3{font-size:15px;font-weight:700}
.topic p{margin-top:6px;font-size:12.5px;color:var(--muted);line-height:1.6}

/* ===== 文章详情页 ===== */
.article{padding:56px 0 76px}
.article-back{font-family:var(--mono);font-size:13px;margin-bottom:30px}
.article-back a{color:var(--muted)}
.article-back a:hover{color:var(--accent)}
.article-meta{display:flex;align-items:center;gap:14px;margin-bottom:14px}
.article-meta time{font-family:var(--mono);font-size:12.5px;color:var(--muted)}
.article-head h1{font-size:33px;line-height:1.4;font-weight:800;letter-spacing:.5px}
.article-body{margin-top:38px;max-width:720px;font-size:15.5px;color:#2a3650}
.article-body p{margin-bottom:18px}
.article-body h2{font-size:19px;font-weight:700;margin:36px 0 14px;color:var(--ink)}
.article-body h2::before{content:"## ";color:var(--accent);font-family:var(--mono);font-weight:400;font-size:15px}
.article-body ul,.article-body ol{margin:0 0 18px 22px}
.article-body li{margin-bottom:8px}
.article-body code{font-family:var(--mono);font-size:13px;background:var(--accent-soft);color:var(--accent-deep);padding:2px 6px;border-radius:5px}
.article-body pre{background:var(--dark);color:#dbe6ff;padding:18px 20px;border-radius:12px;overflow-x:auto;margin:0 0 20px;font-family:var(--mono);font-size:13px;line-height:1.7}
.article-body pre code{background:none;color:inherit;padding:0}
.article-body blockquote{border-left:3px solid var(--accent);background:var(--surface);padding:14px 18px;border-radius:0 10px 10px 0;color:var(--muted);margin:0 0 20px}
.article-end{margin-top:44px;text-align:center;color:var(--muted);font-family:var(--mono);font-size:12px;letter-spacing:2px}

/* ===== 页脚 / 备案信息 ===== */
.footer{background:var(--dark);color:#c9d4e8;padding:44px 0 40px;margin-top:8px}
.footer-inner{display:flex;flex-wrap:wrap;gap:24px;justify-content:space-between;align-items:flex-start}
.footer-brand{font-size:17px;font-weight:700;color:#fff;letter-spacing:1px}
.footer-brand small{display:block;margin-top:8px;font-size:12px;color:#7d8ba6;font-weight:400;letter-spacing:0}
.filing{text-align:right;font-size:13px;line-height:2.1}
.filing a{color:#9db4e8;font-family:var(--mono);font-size:12.5px;border-bottom:1px dotted #3a4a6b;padding-bottom:1px}
.filing a:hover{color:#fff;border-color:#fff}
.filing .pending{color:#7d8ba6}

@media (max-width:720px){
  .hero-title{font-size:42px}
  .hero{padding:64px 0 56px}
  .note{flex-direction:column;gap:6px}
  .about{grid-template-columns:1fr}
  .footer-inner{flex-direction:column}
  .filing{text-align:left}
  .nav-links{gap:18px}
  .section{padding:48px 0}
  .article-head h1{font-size:26px}
}