:root{
  --ink:#0f1b2d; --ink-soft:#33455c; --muted:#6b7a90;
  --line:#e3e8ef; --bg:#ffffff; --band:#f6f8fb;
  --accent:#0e6e7a; --accent-d:#0a5560; --gold:#b07d2b;
  --maxw:1060px;
}
*{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;
  line-height:1.6; font-size:17px; -webkit-font-smoothing:antialiased;
}
.wrap{max-width:var(--maxw); margin:0 auto; padding:0 22px}
.mono{font-family:"SF Mono",ui-monospace,Menlo,Consolas,monospace}
a{color:var(--accent); text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3{line-height:1.2; color:var(--ink); letter-spacing:-.01em}
.muted{color:var(--muted)}
.small{font-size:14px}

/* header */
header.site{border-bottom:1px solid var(--line); position:sticky; top:0; background:rgba(255,255,255,.92); backdrop-filter:saturate(180%) blur(8px); z-index:10}
.nav{display:flex; align-items:center; justify-content:space-between; height:62px}
.brand{font-weight:700; color:var(--ink)}
.brand .mono{background:var(--ink); color:#fff; padding:2px 7px; border-radius:5px; font-size:.82em; letter-spacing:.04em}
.brand-full{font-weight:600; margin-left:6px}
header nav a{color:var(--ink-soft); margin-left:22px; font-size:15px; font-weight:500}
@media(max-width:640px){.brand-full{display:none} header nav a{margin-left:14px}}

/* hero */
.hero{padding:84px 0 70px; border-bottom:1px solid var(--line)}
.eyebrow{color:var(--accent-d); font-weight:600; font-size:14px; text-transform:uppercase; letter-spacing:.08em; margin:0 0 18px}
.hero h1{font-size:48px; margin:0 0 22px; max-width:18ch}
.hl{color:var(--accent)}
.lead{font-size:20px; color:var(--ink-soft); max-width:60ch; margin:0 0 30px}
.cta{display:flex; gap:12px; flex-wrap:wrap}
.btn{display:inline-block; padding:12px 20px; border-radius:8px; border:1px solid var(--line); color:var(--ink); font-weight:600; font-size:15px}
.btn:hover{text-decoration:none; border-color:var(--accent)}
.btn.primary{background:var(--accent); border-color:var(--accent); color:#fff}
.btn.primary:hover{background:var(--accent-d)}
@media(max-width:640px){.hero h1{font-size:34px} .lead{font-size:18px}}

/* band */
.band{background:var(--band); border-bottom:1px solid var(--line); padding:56px 0}
section.section{padding:64px 0}
h2{font-size:30px; margin:0 0 10px}
.sub{color:var(--ink-soft); max-width:64ch; margin:0 0 28px; font-size:18px}

/* id grid */
.idgrid{display:grid; grid-template-columns:repeat(5,1fr); gap:14px}
.idcard{background:#fff; border:1px solid var(--line); border-radius:10px; padding:18px 14px; text-align:center}
.idcard .tag{display:inline-block; font-size:13px; background:#eef2f7; color:var(--ink-soft); padding:3px 9px; border-radius:6px; margin-bottom:8px}
.idcard span:last-child{display:block; color:var(--muted); font-size:14px}
.idcard.now{border-color:var(--accent); box-shadow:0 0 0 2px rgba(14,110,122,.12)}
.idcard.now .tag{background:var(--accent); color:#fff}
.idcard.now span:last-child{color:var(--accent-d); font-weight:600}
@media(max-width:720px){.idgrid{grid-template-columns:repeat(2,1fr)} .idcard.now{grid-column:span 2}}

/* cards */
.cards{display:grid; grid-template-columns:repeat(3,1fr); gap:18px}
.card{border:1px solid var(--line); border-radius:12px; padding:22px; background:#fff}
.card h3{font-size:17px; margin:0 0 8px; color:var(--accent-d)}
.card p{margin:0; color:var(--ink-soft); font-size:15.5px}
@media(max-width:820px){.cards{grid-template-columns:1fr 1fr}}
@media(max-width:560px){.cards{grid-template-columns:1fr}}

/* claim object */
.claim{background:#fff; border:1px solid var(--line); border-left:4px solid var(--accent); border-radius:12px; padding:26px; max-width:760px; box-shadow:0 8px 30px rgba(15,27,45,.06)}
.claim-head{display:flex; align-items:center; gap:12px; margin-bottom:14px}
.claim .id{font-size:15px; background:var(--ink); color:#fff; padding:4px 9px; border-radius:6px}
.chip{font-size:13px; background:#eef2f7; color:var(--ink-soft); padding:3px 10px; border-radius:20px; text-transform:uppercase; letter-spacing:.04em}
.claim-text{font-size:19px; color:var(--ink); margin:0 0 18px; font-weight:500}
.dims{display:flex; gap:10px; flex-wrap:wrap; margin-bottom:16px}
.dim{flex:1; min-width:150px; background:var(--band); border:1px solid var(--line); border-radius:9px; padding:10px 12px}
.dim-k{display:block; font-size:12px; text-transform:uppercase; letter-spacing:.05em; color:var(--muted)}
.dim-v{font-weight:600}
.dim-v.muted{color:var(--muted); font-weight:500}
.state-emerging{color:#c47d12}
.claim-evi,.claim-gap{margin:6px 0 0; font-size:14.5px; color:var(--ink-soft)}
.fineprint{margin-top:18px; color:var(--muted); font-size:15px; font-style:italic}

/* hypothesis */
.hyp{border-left:4px solid var(--gold); background:var(--band); margin:0 0 22px; padding:22px 26px; border-radius:0 10px 10px 0; font-size:22px; color:var(--ink); font-weight:500; max-width:70ch}

/* pilot */
.pilot{display:grid; grid-template-columns:1.3fr 1fr; gap:34px; align-items:start}
.pilot h2{margin-top:0}
.pilot p{color:var(--ink-soft)}
.stat{font-size:16px; color:var(--ink)!important}
.stat strong{font-size:24px; color:var(--accent-d)}
.priorart{background:#fff; border:1px solid var(--line); border-radius:12px; padding:24px}
.priorart h3{margin:0 0 8px; font-size:17px}
.priorart p{margin:0; font-size:15px}
@media(max-width:760px){.pilot{grid-template-columns:1fr}}

/* footer */
footer.site{border-top:1px solid var(--line); padding:40px 0; background:var(--band)}
.foot{display:flex; justify-content:space-between; gap:24px; flex-wrap:wrap}
.foot .brand{color:var(--ink); margin:0 0 4px}
.foot p{margin:0 0 4px}

/* ===== language toggle + claims page ===== */
header nav a.lang{border:1px solid var(--line); border-radius:6px; padding:3px 9px; font-size:13px; color:var(--accent-d)}
header nav a.active{color:var(--accent-d); font-weight:700}

.claims-hero{padding:54px 0 8px}
.claims-hero h1{font-size:34px; margin:0 0 10px}
.filters{display:flex; gap:10px; flex-wrap:wrap; margin:22px 0 8px}
.fbtn{cursor:pointer; background:#fff; border:1px solid var(--line); border-radius:20px; padding:7px 14px; font-size:14px; color:var(--ink-soft); font-weight:600}
.fbtn:hover{border-color:var(--accent)}
.fbtn.active{background:var(--ink); color:#fff; border-color:var(--ink)}
.fct{opacity:.6; font-weight:500}
.fbtn.active .fct{opacity:.8}

.claims-bg{background:var(--band); border-top:1px solid var(--line)}
.claims-list{padding:26px 22px 84px; display:grid; gap:20px}
.claim-row{border:1px solid #d7deea; border-left:4px solid var(--accent); border-radius:12px; padding:22px 24px; background:#fff; box-shadow:0 4px 16px rgba(15,27,45,.07); transition:box-shadow .15s,transform .15s}
.claim-row:hover{box-shadow:0 10px 28px rgba(15,27,45,.12); transform:translateY(-1px)}
.cr-head{display:flex; align-items:center; gap:10px; flex-wrap:wrap; margin-bottom:10px}
.cr-head .id{font-size:13.5px; background:var(--ink); color:#fff; padding:3px 8px; border-radius:5px}
.badge{font-size:12px; font-weight:700; padding:3px 10px; border-radius:20px; text-transform:uppercase; letter-spacing:.04em}
.st-established{background:#e2f3ec; color:#1d7a4f}
.st-probable{background:#e6f0f6; color:#1f6a93}
.st-emerging{background:#fcf0dd; color:#b07d2b}
.st-speculative{background:#f3e7ea; color:#a23b52}
.cr-text{font-size:17px; color:var(--ink); margin:0 0 12px; font-weight:500}
.cr-meta{font-size:14px; color:var(--ink-soft); margin-bottom:8px}
.cr-evi{font-size:13px; color:var(--accent-d); margin:0 0 8px; word-break:break-word}
.cr-gap{font-size:14px; color:var(--muted); margin:0}
.cr-gap strong{color:var(--ink-soft)}
@media(max-width:560px){.claims-list{padding-left:0; padding-right:0} .claims-hero h1{font-size:28px}}

/* ===== layered architecture + related work ===== */
.layers{display:grid; grid-template-columns:repeat(3,1fr); gap:18px; margin-top:8px}
.layer{border:1px solid var(--line); border-radius:12px; padding:22px; background:#fff}
.layer.l1{border-color:var(--accent); box-shadow:0 6px 22px rgba(14,110,122,.10)}
.layer .lnum{display:block; font-size:12px; text-transform:uppercase; letter-spacing:.06em; color:var(--muted); margin-bottom:6px}
.layer.l1 .lnum{color:var(--accent-d); font-weight:700}
.layer h3{margin:0 0 8px; font-size:18px}
.layer p{margin:0; color:var(--ink-soft); font-size:15px}
.related{max-width:74ch; color:var(--ink-soft); font-size:16.5px}
@media(max-width:760px){.layers{grid-template-columns:1fr}}

/* ===== minimalist RFC homepage ===== */
.rfc{max-width:680px; padding:74px 22px 96px}
.rfc h1{font-size:32px; margin:0 0 30px; letter-spacing:-.02em}
.rfc-lede{font-size:23px; line-height:1.65; color:var(--ink); margin:0 0 34px}
.rfc-lede strong{color:var(--accent-d)}
.rfc-body{font-size:18px; color:var(--ink-soft); margin:0 0 14px}
.rfc-list{font-size:18px; color:var(--ink); margin:0 0 34px; padding-left:22px; line-height:1.85}
.rfc-goal{font-size:20px; color:var(--ink); border-left:3px solid var(--gold); padding-left:18px; margin:0 0 38px; line-height:1.6}
.rfc-goal strong{color:var(--accent-d)}
.rfc-links{font-size:16px; margin:0 0 44px}
.rfc-links .sep{color:var(--muted); margin:0 6px}
.rfc-note{font-size:13.5px; color:var(--muted); border-top:1px solid var(--line); padding-top:22px; line-height:1.7}
@media(max-width:560px){.rfc{padding-top:48px} .rfc-lede{font-size:20px}}

/* ===== homepage tagline ===== */
.rfc-tagline{font-size:17px; color:var(--accent-d); font-weight:600; margin:-14px 0 30px; line-height:1.5}

/* ===== question pages ===== */
.qpage{max-width:760px; padding:48px 22px 80px}
.qpage .qid{font-size:13px; color:var(--muted); margin:0 0 8px}
.qtitle{font-size:30px; line-height:1.25; margin:0 0 24px}
.answer{background:var(--band); border-left:4px solid var(--accent); border-radius:0 10px 10px 0; padding:18px 22px; margin:0 0 22px}
.answer .alabel{display:block; font-size:12px; text-transform:uppercase; letter-spacing:.06em; color:var(--accent-d); font-weight:700; margin-bottom:6px}
.answer p{margin:0; font-size:18px; color:var(--ink); line-height:1.6}
.qmeta{display:flex; gap:14px; flex-wrap:wrap; margin:0 0 22px}
.qmeta>div{flex:1; min-width:150px; background:#fff; border:1px solid var(--line); border-radius:10px; padding:10px 14px}
.qmeta .mk{display:block; font-size:11px; text-transform:uppercase; letter-spacing:.05em; color:var(--muted); margin-bottom:4px}
.evdir{display:flex; gap:12px; margin:0 0 26px}
.ev{flex:1; text-align:center; border:1px solid var(--line); border-radius:10px; padding:14px; background:#fff}
.ev b{display:block; font-size:26px; line-height:1}
.ev span{font-size:13px; color:var(--muted)}
.ev.sup b{color:#1d7a4f} .ev.con b{color:#a23b52} .ev.oth b{color:#1f6a93}
.qpage h2{font-size:15px; text-transform:uppercase; letter-spacing:.04em; margin:28px 0 12px; padding-bottom:6px; border-bottom:1px solid var(--line); color:var(--ink-soft)}
.changed,.uncert{font-size:16px; color:var(--ink-soft); margin:0}
.qclaims{list-style:none; padding:0; margin:0; display:grid; gap:10px}
.qclaims li{border:1px solid var(--line); border-radius:9px; padding:12px 14px; font-size:15px}
.qclaims .cid{font-size:12.5px}
.role{font-size:11px; text-transform:uppercase; letter-spacing:.04em; padding:2px 8px; border-radius:20px; margin-left:6px}
.role-supporting{background:#e2f3ec; color:#1d7a4f}
.role-contradicting{background:#f3e7ea; color:#a23b52}
.role-refines{background:#e6f0f6; color:#1f6a93}
.role-context{background:#eef2f7; color:#56657d}
.ctext{color:var(--ink-soft)}
.verhist{list-style:none; padding:0; margin:0; font-size:14px; color:var(--ink-soft)}
.refs{font-size:13px; color:var(--accent-d); word-break:break-word}
.backlink{margin-top:30px}
.qgrid{display:grid; grid-template-columns:repeat(2,1fr); gap:16px; padding:26px 22px 84px}
.qcard{display:block; background:#fff; border:1px solid #d7deea; border-radius:12px; padding:20px; box-shadow:0 4px 16px rgba(15,27,45,.06); transition:box-shadow .15s,transform .15s}
.qcard:hover{text-decoration:none; box-shadow:0 10px 26px rgba(15,27,45,.12); transform:translateY(-1px)}
.qc-head{display:flex; justify-content:space-between; align-items:center; gap:8px; margin-bottom:8px}
.qc-head .qid{font-size:12px; color:var(--muted)}
.qcard h3{font-size:17px; margin:0 0 8px; color:var(--ink); line-height:1.3}
.qc-ans{font-size:14px; color:var(--ink-soft); margin:0 0 10px}
.qc-ev{font-size:13px; color:var(--muted); margin:0}
.qc-ev .sup{color:#1d7a4f} .qc-ev .con{color:#a23b52}
@media(max-width:680px){.qgrid{grid-template-columns:1fr} .evdir{flex-wrap:wrap}}

/* knowledge freshness */
.fresh{color:var(--accent-d); font-weight:600}
.frnote{font-size:13.5px; color:var(--ink-soft); background:var(--band); border:1px solid var(--line); border-radius:8px; padding:11px 14px; margin:0 0 8px}
.qid a{font-weight:600}

/* citation formats */
.cite-tabs{display:flex; gap:6px; flex-wrap:wrap; margin:0 0 10px; align-items:center}
.ctab{cursor:pointer; background:#fff; border:1px solid var(--line); border-radius:18px; padding:4px 12px; font-size:13px; color:var(--ink-soft); font-weight:600}
.ctab.active{background:var(--ink); color:#fff; border-color:var(--ink)}
.copybtn{margin-left:auto; cursor:pointer; background:var(--accent); color:#fff; border:none; border-radius:7px; padding:5px 12px; font-size:13px; font-weight:600}
.copybtn:hover{background:var(--accent-d)}
.cite-out{background:#fff; border:1px solid var(--line); border-radius:8px; padding:12px 14px; font-size:13px; white-space:pre-wrap; word-break:break-word; margin:0 0 8px; font-family:"SF Mono",ui-monospace,Menlo,monospace; color:var(--ink)}