/* ===== 知行AI 官网 · 深色主题 ===== */
:root{
  --bg:#05060a; --bg2:#0a0d14; --card:#10141d; --card2:#151a26;
  --line:#1e2433; --text:#e9ecf5; --muted:#8b93a7; --dim:#5c6478;
  --acc:#6366f1; --acc2:#8b5cf6; --cyan:#7dd3fc;
  --grad:linear-gradient(120deg,#6366f1,#8b5cf6);
  --radius:16px;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  background:var(--bg); color:var(--text);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  font-size:16px; line-height:1.7; -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}
img{max-width:100%}

/* ---------- 顶部导航 ---------- */
.topnav{position:fixed;top:0;left:0;right:0;z-index:100;
  background:rgba(5,6,10,.75);backdrop-filter:blur(14px);border-bottom:1px solid rgba(30,36,51,.6)}
.nav-inner{max-width:1200px;margin:0 auto;height:64px;padding:0 24px;
  display:flex;align-items:center;gap:32px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;font-size:18px;white-space:nowrap}
.brand-mark{flex:none;display:block}
.nav-links{display:flex;gap:26px;margin:0 auto}
.nav-links a{color:var(--muted);font-size:15px;transition:color .15s}
.nav-links a:hover,.nav-links a.on{color:var(--text)}
.nav-links a.on{font-weight:600}
.nav-right{display:flex;align-items:center;gap:18px;white-space:nowrap}
.nav-account{color:var(--muted);font-size:15px}
.nav-account:hover{color:var(--text)}
.nav-burger{display:none;background:none;border:none;color:var(--text);font-size:22px;cursor:pointer}
.nav-mobile{display:none}

/* ---------- 按钮 ---------- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;
  border-radius:999px;font-weight:600;cursor:pointer;border:none;transition:all .18s}
.btn-primary{background:var(--grad);color:#fff;box-shadow:0 4px 24px rgba(99,102,241,.35)}
.btn-primary:hover{filter:brightness(1.12);transform:translateY(-1px)}
.btn-ghost{background:rgba(255,255,255,.06);color:var(--text);border:1px solid var(--line)}
.btn-ghost:hover{background:rgba(255,255,255,.1)}
.btn-sm{padding:8px 20px;font-size:14px}
.btn-lg{padding:14px 38px;font-size:16px}

/* ---------- 首页 hero ---------- */
.hero{position:relative;padding:170px 24px 110px;text-align:center;overflow:hidden}
.hero::before{content:"";position:absolute;inset:0;pointer-events:none;
  background:radial-gradient(800px 420px at 50% -10%,rgba(99,102,241,.18),transparent 65%),
             radial-gradient(600px 380px at 82% 18%,rgba(125,211,252,.07),transparent 60%);}
.hero-badge{display:inline-flex;align-items:center;gap:8px;padding:8px 18px;border-radius:999px;
  background:rgba(255,255,255,.05);border:1px solid var(--line);color:var(--muted);font-size:14px;margin-bottom:38px}
.hero-badge .dot{width:8px;height:8px;border-radius:50%;background:var(--cyan);box-shadow:0 0 10px var(--cyan)}
.hero h1{font-size:clamp(40px,7vw,84px);font-weight:900;letter-spacing:.02em;line-height:1.18}
.hero h1 .hl{color:var(--cyan)}
.hero .sub{max-width:640px;margin:30px auto 0;color:var(--muted);font-size:clamp(16px,2vw,19px)}
.hero-cta{margin-top:44px;display:flex;gap:16px;justify-content:center;flex-wrap:wrap}
.hero-meta{margin-top:26px;color:var(--dim);font-size:14px}
.hero-meta i{margin:0 10px;font-style:normal}

/* ---------- 通用 section ---------- */
.section{max-width:1200px;margin:0 auto;padding:80px 24px}
.sec-label{text-align:center;color:var(--acc);font-size:14px;font-weight:600;letter-spacing:.1em}
.sec-title{text-align:center;font-size:clamp(28px,4.5vw,48px);font-weight:800;margin-top:12px;line-height:1.3}
.sec-sub{text-align:center;color:var(--muted);max-width:560px;margin:18px auto 0}

/* ---------- 数据带 ---------- */
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;margin-top:56px;
  background:var(--card);border-radius:20px;padding:44px 8px;border:1px solid var(--line)}
.stat{text-align:center}
.stat b{font-size:clamp(34px,4.5vw,56px);font-weight:800}
.stat span{display:block;color:var(--muted);margin-top:6px;font-size:14px}

/* ---------- 功能卡片 ---------- */
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:48px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:28px;transition:all .2s}
.card:hover{border-color:#2c3550;transform:translateY(-3px)}
.card .ico{width:44px;height:44px;border-radius:12px;background:rgba(99,102,241,.12);
  display:flex;align-items:center;justify-content:center;font-size:22px;margin-bottom:16px}
.card h3{font-size:18px;margin-bottom:8px}
.card p{color:var(--muted);font-size:14.5px}

/* ---------- 首页专栏精选 ---------- */
.pick-head{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:22px}
.pick-head h2{font-size:24px}
.pick-head a{color:var(--acc);font-size:14px}
.pick-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.pick{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:20px 22px;transition:all .2s}
.pick:hover{border-color:#2c3550}
.pick h4{font-size:16px;line-height:1.5}
.pick time{display:block;color:var(--dim);font-size:13px;margin-top:12px}

/* ---------- CTA 横幅 ---------- */
.cta-band{text-align:center;background:linear-gradient(180deg,rgba(99,102,241,.10),rgba(139,92,246,.05));
  border:1px solid var(--line);border-radius:24px;padding:64px 24px;margin:0 24px}
.cta-wrap{max-width:1200px;margin:0 auto 90px}
.cta-band h2{font-size:clamp(26px,4vw,40px);font-weight:800}
.cta-band p{color:var(--muted);margin:14px 0 30px}

/* ---------- 下载页 ---------- */
.dl-hero{padding:150px 24px 20px;text-align:center}
.dl-hero h1{font-size:clamp(40px,6vw,72px);font-weight:900}
.dl-hero p{color:var(--muted);margin-top:16px;font-size:17px}
.dl-cards{display:grid;grid-template-columns:repeat(2,minmax(0,480px));gap:24px;justify-content:center;
  max-width:1060px;margin:56px auto 0;padding:0 24px}
.dl-card{position:relative;background:var(--card);border:1px solid var(--line);border-radius:22px;
  padding:48px 36px;text-align:center}
.dl-card.win{border-color:rgba(99,102,241,.55);box-shadow:0 0 40px rgba(99,102,241,.10)}
.dl-tag{position:absolute;top:18px;right:18px;font-size:12px;color:var(--cyan);
  background:rgba(125,211,252,.1);border:1px solid rgba(125,211,252,.25);padding:4px 12px;border-radius:999px}
.dl-card .os-ico{font-size:48px}
.dl-card h2{font-size:26px;margin:18px 0 8px}
.dl-card .req{color:var(--muted);font-size:15px;margin-bottom:28px}
.dl-card .ver{color:var(--dim);font-size:13.5px;margin-top:16px}
.dl-soon{display:inline-flex;padding:14px 38px;border-radius:999px;background:rgba(255,255,255,.05);
  color:var(--dim);border:1px solid var(--line);font-weight:600}
.dl-web{ text-align:center;margin:48px 0 100px;color:var(--muted)}
.dl-web a{color:var(--text);border-bottom:1px solid var(--dim)}

/* ---------- 专栏 ---------- */
.page-hero{padding:150px 24px 30px;max-width:960px;margin:0 auto}
.page-hero .sec-label{text-align:left}
.page-hero h1{font-size:clamp(32px,5vw,52px);font-weight:900;margin-top:10px}
.page-hero .desc{color:var(--muted);margin-top:14px}
.page-hero .tip{color:var(--dim);font-size:14px;margin-top:8px}
.page-hero .tip a{color:var(--acc);text-decoration:underline}
.art-list{max-width:960px;margin:30px auto 100px;padding:0 24px;display:flex;flex-direction:column;gap:18px}
.art-item{display:block;background:var(--card);border:1px solid var(--line);border-radius:16px;
  padding:26px 30px;transition:all .2s}
.art-item:hover{border-color:#2c3550;transform:translateY(-2px)}
.art-item h3{font-size:19px}
.art-item .pin{font-size:12px;color:var(--cyan);border:1px solid rgba(125,211,252,.3);
  padding:1px 8px;border-radius:999px;margin-right:8px;vertical-align:2px}
.art-item p{color:var(--muted);font-size:15px;margin-top:8px}
.art-item .meta{color:var(--dim);font-size:13px;margin-top:14px}
.art-item .meta i{font-style:normal;margin-right:14px}

/* ---------- 文章详情 / Markdown 正文 ---------- */
.art-detail{max-width:820px;margin:0 auto 80px;padding:150px 24px 0}
.art-detail h1.art-title{font-size:clamp(28px,4.5vw,42px);font-weight:800;line-height:1.35}
.art-detail .meta{color:var(--dim);font-size:14px;margin:18px 0 40px}
.art-detail .meta i{font-style:normal;margin-right:16px}
.md{color:#d4d9e6;font-size:16.5px}
.md h1,.md h2{font-size:26px;margin:44px 0 16px;color:var(--text);border-bottom:1px solid var(--line);padding-bottom:10px}
.md h3{font-size:21px;margin:34px 0 12px;color:var(--text)}
.md h4,.md h5{font-size:17px;margin:26px 0 10px;color:var(--text)}
.md p{margin:14px 0}
.md ul,.md ol{margin:14px 0;padding-left:26px}
.md li{margin:6px 0}
.md strong{color:var(--text)}
.md a{color:var(--acc);text-decoration:underline}
.md blockquote{border-left:3px solid var(--acc);background:rgba(99,102,241,.06);
  padding:12px 18px;border-radius:0 10px 10px 0;margin:18px 0;color:var(--muted)}
.md code{background:#171c29;border:1px solid var(--line);border-radius:6px;padding:2px 7px;font-size:14px}
.md pre{background:#0c0f17;border:1px solid var(--line);border-radius:12px;padding:18px;overflow-x:auto;margin:18px 0}
.md pre code{background:none;border:none;padding:0}
.md img{border-radius:12px;border:1px solid var(--line);margin:16px 0;display:block}
.md table{width:100%;border-collapse:collapse;margin:18px 0;display:block;overflow-x:auto}
.md th,.md td{border:1px solid var(--line);padding:9px 13px;font-size:14.5px;text-align:left}
.md th{background:var(--card2);color:var(--text)}
.md hr{border:none;border-top:1px solid var(--line);margin:34px 0}
.more-box{max-width:820px;margin:0 auto 100px;padding:0 24px}
.more-box h4{color:var(--muted);font-weight:600;margin-bottom:14px}

/* ---------- 指南（蓝皮书） ---------- */
.guide-wrap{display:flex;max-width:1280px;margin:0 auto;padding:64px 0 0;min-height:100vh}
.guide-side{width:280px;flex:none;border-right:1px solid var(--line);
  padding:36px 18px 60px;position:sticky;top:64px;height:calc(100vh - 64px);overflow-y:auto}
.guide-side .g-head{font-weight:700;font-size:17px;padding:0 12px 18px}
.guide-side a{display:block;padding:9px 14px;border-radius:10px;color:var(--muted);font-size:14.5px;margin:2px 0}
.guide-side a:hover{background:rgba(255,255,255,.05);color:var(--text)}
.guide-side a.on{background:rgba(99,102,241,.14);color:var(--text);font-weight:600}
.guide-side .g-child{padding-left:28px;font-size:13.5px}
.guide-main{flex:1;min-width:0;padding:44px 48px 100px}
.guide-main .md h1:first-child{margin-top:0}
.guide-title{font-size:clamp(26px,3.5vw,36px);font-weight:800;margin-bottom:8px}
.guide-updated{color:var(--dim);font-size:13px;margin-bottom:36px}
.guide-nav-btm{display:flex;justify-content:space-between;margin-top:60px;gap:14px}
.guide-nav-btm a{flex:1;background:var(--card);border:1px solid var(--line);border-radius:12px;
  padding:14px 18px;font-size:14px;color:var(--muted)}
.guide-nav-btm a:hover{color:var(--text);border-color:#2c3550}
.guide-empty{padding:180px 24px;text-align:center;color:var(--muted)}

/* ---------- 页脚 ---------- */
.footer{border-top:1px solid var(--line);background:var(--bg2);margin-top:40px}
.footer-inner{max-width:1200px;margin:0 auto;padding:56px 24px 30px;
  display:flex;justify-content:space-between;gap:40px;flex-wrap:wrap}
.footer-brand p{color:var(--dim);font-size:14px;margin-top:10px}
.footer-cols{display:flex;gap:70px;flex-wrap:wrap}
.footer-cols h5{font-size:14px;color:var(--text);margin-bottom:14px}
.footer-cols a{display:block;color:var(--muted);font-size:14px;margin:8px 0}
.footer-cols a:hover{color:var(--text)}
.footer-note{border-top:1px solid var(--line);padding:22px 24px;text-align:center;color:var(--dim);font-size:13px}
.footer-note a{color:var(--dim)}
.footer-note p{margin:4px 0}

/* ---------- 错误页 ---------- */
.err-page{padding:200px 24px;text-align:center}
.err-page b{font-size:72px;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.err-page p{color:var(--muted);margin:16px 0 30px}

/* ---------- 响应式 ---------- */
@media (max-width: 920px){
  .cards{grid-template-columns:1fr 1fr}
  .pick-grid{grid-template-columns:1fr}
  .stats{grid-template-columns:1fr 1fr;gap:28px}
  .dl-cards{grid-template-columns:1fr}
  .guide-side{display:none}
  .guide-main{padding:36px 22px 80px}
}
@media (max-width: 680px){
  .nav-links,.nav-account{display:none}
  .nav-burger{display:block;margin-left:auto}
  .nav-right{margin-left:auto}
  .nav-inner{gap:14px}
  body.nav-open .nav-mobile{display:flex;flex-direction:column;
    background:var(--bg2);border-bottom:1px solid var(--line);padding:10px 24px 18px}
  .nav-mobile a{padding:11px 0;color:var(--muted);border-bottom:1px dashed rgba(30,36,51,.5)}
  .cards{grid-template-columns:1fr}
}