:root{
  --cf-orange:#f6821f; --cf-orange-d:#d96d15;
  --ink:#1d1d1f; --muted:#6b7280; --line:#e6e8eb; --bg:#ffffff;
  --sidebar-bg:#fafafa; --code-bg:#f6f8fa; --accent-soft:#fff4e8;
  --sidebar-w:280px; --rightbar-w:240px; --topbar-h:56px;
  --maxw:820px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;color:var(--ink);background:var(--bg);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  font-size:16px;line-height:1.65;-webkit-font-smoothing:antialiased}
a{color:var(--cf-orange-d);text-decoration:none}
a:hover{text-decoration:underline}

/* Topbar */
.topbar{position:sticky;top:0;z-index:30;height:var(--topbar-h);display:flex;align-items:center;gap:10px;
  padding:0 16px;background:#fff;border-bottom:1px solid var(--line);box-shadow:0 1px 2px rgba(0,0,0,.03)}
.brand{font-weight:700;color:var(--ink);font-size:16px;display:flex;align-items:center;gap:9px;min-width:0}
.brand:hover{text-decoration:none}
.brand-mark{flex:none;display:inline-flex;width:28px;height:28px;align-items:center;justify-content:center;
  background:var(--cf-orange);color:#fff;border-radius:7px;font-size:16px}
.brand-text{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.topbar-actions{margin-left:auto;display:flex;align-items:center;gap:10px;flex:none}
.topbar-link{color:var(--muted);font-size:14px;white-space:nowrap}
.topbar-link:hover{color:var(--ink)}
.tg-top{display:inline-flex;align-items:center;gap:6px;background:#229ED9;color:#fff;font-weight:600;
  font-size:13.5px;padding:7px 13px;border-radius:8px}
.tg-top:hover{background:#1c87ba;text-decoration:none}
.tg-top svg{flex:none}
.langsw{position:relative}
.langsw summary{list-style:none;display:inline-flex;align-items:center;gap:6px;cursor:pointer;
  border:1px solid var(--line);border-radius:8px;background:#fff;padding:6px 10px;font-size:13px;font-weight:600;color:#374151}
.langsw summary::-webkit-details-marker{display:none}
.langsw summary::marker{content:""}
.langsw summary:hover{background:#f0f1f3}
.langsw-globe{color:var(--muted);flex:none}
.langsw-cur{white-space:nowrap;max-width:9em;overflow:hidden;text-overflow:ellipsis}
.langsw-caret{color:var(--muted);transition:transform .15s;flex:none}
.langsw[open] .langsw-caret{transform:rotate(180deg)}
.langsw-menu{position:absolute;top:calc(100% + 8px);right:0;min-width:158px;background:#fff;
  border:1px solid var(--line);border-radius:10px;box-shadow:0 10px 30px rgba(0,0,0,.15);padding:6px;z-index:40}
.langsw-menu a{display:block;padding:9px 13px;border-radius:7px;font-size:14px;color:#374151;white-space:nowrap}
.langsw-menu a:hover{background:#f0f1f3;text-decoration:none}
.langsw-menu a.active{background:var(--accent-soft);color:var(--cf-orange-d);font-weight:700}
.entag{display:inline-block;font-size:10px;font-weight:700;color:var(--muted);border:1px solid var(--line);border-radius:4px;padding:0 4px;margin-left:4px;vertical-align:middle}
.menu-btn{display:none;background:none;border:1px solid var(--line);border-radius:8px;cursor:pointer;
  width:38px;height:38px;align-items:center;justify-content:center;flex:none}
.menu-bars,.menu-bars::before,.menu-bars::after{display:block;width:18px;height:2px;background:var(--ink);border-radius:2px;transition:.2s}
.menu-bars{position:relative}
.menu-bars::before,.menu-bars::after{content:"";position:absolute;left:0}
.menu-bars::before{top:-6px}.menu-bars::after{top:6px}
body.nav-open .menu-bars{background:transparent}
body.nav-open .menu-bars::before{transform:rotate(45deg);top:0}
body.nav-open .menu-bars::after{transform:rotate(-45deg);top:0}
/* Extra links shown only in the mobile drawer */
.nav-extra{display:none}
.nav-ext-link{display:block;padding:9px 10px;border-radius:8px;color:#374151;font-size:14.5px;font-weight:600}
.nav-ext-link:hover{background:#f0f1f3;text-decoration:none}

/* Layout */
.layout{display:grid;grid-template-columns:var(--sidebar-w) minmax(0,1fr) var(--rightbar-w);
  align-items:start;max-width:1400px;margin:0 auto}
.sidebar{position:sticky;top:var(--topbar-h);height:calc(100vh - var(--topbar-h));overflow-y:auto;
  background:var(--sidebar-bg);border-right:1px solid var(--line);padding:20px 14px}
.content{min-width:0;padding:36px 48px 80px;max-width:calc(var(--maxw) + 96px);margin:0 auto;width:100%}
.rightbar{position:sticky;top:var(--topbar-h);height:calc(100vh - var(--topbar-h));overflow-y:auto;padding:36px 16px}

/* Sidebar nav */
.nav-home{display:block;font-weight:600;color:var(--ink);padding:6px 10px;border-radius:6px;margin-bottom:10px}
.nav-home.active,.nav-home:hover{background:var(--accent-soft);text-decoration:none}
.nav-group{margin-bottom:18px}
.nav-group-title{font-size:12px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);
  padding:0 10px;margin-bottom:6px}
.sidebar ul{list-style:none;margin:0;padding:0}
.sidebar li a{display:block;padding:6px 10px;border-radius:6px;color:#374151;font-size:14.5px}
.sidebar li a:hover{background:#f0f1f3;text-decoration:none}
.sidebar li a.active{background:var(--accent-soft);color:var(--cf-orange-d);font-weight:600;
  box-shadow:inset 2px 0 0 var(--cf-orange)}

/* Right TOC */
.toc-title{font-size:12px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);margin-bottom:8px}
.toc ul{list-style:none;margin:0;padding:0}
.toc li a{display:block;color:var(--muted);font-size:13px;padding:3px 0;border-left:2px solid transparent;padding-left:10px}
.toc li a:hover{color:var(--ink);text-decoration:none}
.toc li a.active{color:var(--cf-orange-d);border-left-color:var(--cf-orange);font-weight:600}
.toc .toc-h3 a{padding-left:22px;font-size:12.5px}

/* Markdown content */
.md h1{font-size:34px;line-height:1.2;margin:0 0 8px;letter-spacing:-.02em}
.md h2{font-size:24px;margin:40px 0 12px;padding-top:12px;border-top:1px solid var(--line);letter-spacing:-.01em}
.md h3{font-size:19px;margin:28px 0 8px}
.md h4{font-size:16px;margin:22px 0 6px;color:#374151}
.md h2:first-child,.md h1:first-child{border:0;margin-top:0;padding-top:0}
.md p{margin:12px 0}
.md a{font-weight:500}
.md ul,.md ol{margin:12px 0;padding-left:24px}
.md li{margin:5px 0}
.md hr{border:0;border-top:1px solid var(--line);margin:32px 0}
.md blockquote{margin:16px 0;padding:12px 18px;background:var(--accent-soft);
  border-left:4px solid var(--cf-orange);border-radius:0 8px 8px 0;color:#5b4a36}
.md blockquote p{margin:6px 0}
.md code{background:var(--code-bg);padding:.15em .4em;border-radius:5px;font-size:.88em;
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}
.md pre{background:var(--code-bg);border:1px solid var(--line);border-radius:10px;padding:16px 18px;
  overflow:auto;margin:16px 0}
.md pre code{background:none;padding:0;font-size:13.5px;line-height:1.55}

/* Tables */
.md table{border-collapse:collapse;width:100%;margin:18px 0;font-size:14.5px;display:block;overflow-x:auto}
.md th,.md td{border:1px solid var(--line);padding:9px 12px;text-align:left;vertical-align:top}
.md thead th{background:#f6f8fa;font-weight:600}
.md tbody tr:nth-child(even){background:#fafbfc}

/* Heading anchor on hover */
.md :is(h2,h3,h4){scroll-margin-top:calc(var(--topbar-h) + 12px)}

/* Prev / next */
.prevnext{display:flex;justify-content:space-between;gap:16px;margin-top:48px;padding-top:24px;border-top:1px solid var(--line)}
.pn{display:flex;flex-direction:column;gap:2px;padding:14px 18px;border:1px solid var(--line);border-radius:10px;
  flex:1;max-width:48%}
.pn:hover{border-color:var(--cf-orange);text-decoration:none;background:var(--accent-soft)}
.pn span{font-size:12px;color:var(--muted)}
.pn strong{color:var(--ink);font-size:15px}
.pn-next{text-align:right;align-items:flex-end}

/* Home */
.hero{padding:24px 0 8px}
.hero h1{font-size:40px;letter-spacing:-.02em;margin:0 0 10px}
.lede{font-size:18px;color:var(--muted);max-width:680px}
.cta{display:inline-block;margin-top:18px;background:var(--cf-orange);color:#fff;font-weight:600;
  padding:12px 22px;border-radius:8px}
.cta:hover{background:var(--cf-orange-d);text-decoration:none}
.cards{display:grid;grid-template-columns:repeat(2,1fr);gap:16px;margin:32px 0}
.card{border:1px solid var(--line);border-radius:12px;padding:20px;background:#fff}
.card:hover{border-color:var(--cf-orange);text-decoration:none;box-shadow:0 4px 16px rgba(0,0,0,.05)}
.card h3{margin:0 0 6px;font-size:17px;color:var(--ink)}
.card p{margin:0;color:var(--muted);font-size:14px}
.modlist{font-size:15px}
.modlist li{margin:8px 0}

/* Contact section (home) */
.contact{display:flex;gap:32px;align-items:center;justify-content:space-between;flex-wrap:wrap;
  margin:40px 0 8px;padding:28px 32px;border:1px solid var(--line);border-radius:16px;
  background:linear-gradient(135deg,#fff7ef 0%,#f3f9f4 100%)}
.contact-text{flex:1;min-width:260px}
.contact-text h2{border:0;margin:0 0 8px;padding:0}
.contact-text p{margin:6px 0;color:#4b5563}
.contact-scan{font-size:14px;color:var(--muted)!important;margin-top:14px!important}
.tg-btn{display:inline-flex;align-items:center;gap:8px;margin-top:6px;background:#229ED9;color:#fff;
  font-weight:600;padding:11px 20px;border-radius:9px}
.tg-btn:hover{background:#1c87ba;text-decoration:none}
.tg-btn svg{flex:none}
.contact-qr{display:flex;flex-direction:column;align-items:center;gap:8px}
.contact-qr img{width:200px;height:auto;border-radius:14px;border:1px solid var(--line);background:#fff}
.contact-qr span{font-weight:700;color:var(--cf-orange-d);letter-spacing:.02em}

/* Diagram figures */
.diagram-fig{margin:22px 0 8px;padding:0}
.diagram-fig img{display:block;width:100%;height:auto;border:1px solid var(--line);border-radius:12px;background:#fff}
.diagram-fig figcaption{margin-top:10px;font-size:13px;color:var(--muted);text-align:center}

/* Site footer (every page) */
.site-footer{border-top:1px solid var(--line);background:var(--sidebar-bg)}
.footer-inner{max-width:1400px;margin:0 auto;padding:18px 24px;display:flex;gap:16px;
  align-items:center;justify-content:space-between;flex-wrap:wrap}
.footer-contact{font-size:14.5px;color:#374151}
.footer-contact a{font-weight:700}
.footer-rights{font-size:12.5px;color:var(--muted)}

/* Mobile */
.scrim{display:none}
@media(max-width:1080px){
  .layout{grid-template-columns:var(--sidebar-w) minmax(0,1fr)}
  .rightbar{display:none}
}
@media(max-width:820px){
  .layout{grid-template-columns:1fr}
  .menu-btn{display:inline-flex}
  .topbar{gap:8px;padding:0 12px}
  .brand{font-size:15px}
  .brand-text{max-width:44vw}
  .topbar-actions{gap:8px}
  .topbar-link{display:none}
  .tg-top .tg-label{display:none}
  .tg-top{padding:8px}
  .content{padding:24px 20px 64px}
  .cards{grid-template-columns:1fr}
  .sidebar{position:fixed;top:var(--topbar-h);left:0;width:var(--sidebar-w);max-width:84vw;
    transform:translateX(-100%);transition:transform .2s ease;z-index:25;box-shadow:2px 0 18px rgba(0,0,0,.14)}
  body.nav-open .sidebar{transform:translateX(0)}
  body.nav-open .scrim{display:block;position:fixed;inset:var(--topbar-h) 0 0 0;background:rgba(0,0,0,.35);z-index:20}
  .nav-extra{display:block;margin-top:18px;padding-top:14px;border-top:1px solid var(--line)}
  .hero h1{font-size:30px}
  .pn{max-width:none}
}
@media(max-width:380px){
  .brand-text{display:none}
  .langsw-cur{display:none}
}