/* ==========================================================================
   MatterGPT_RL — shared design system  (site.css)
   Dark theme, minimal text, lead-with-conclusion, 5-band system.
   Dependency-free. Copy components verbatim from the reference doc.
   ========================================================================== */

:root{
  /* palette */
  --bg:#0d1117; --panel:#161b22; --line:#283041;
  --fg:#e6edf3; --mut:#9da7b3;
  --ac:#0072B2;   /* blue   */
  --ok:#009E73;   /* green  */
  --bad:#D55E00;  /* orange */
  --amber:#E0A800;
  /* derived tints (low-alpha washes for band backgrounds) */
  --ac-t:rgba(0,114,178,.12);
  --ok-t:rgba(0,158,115,.12);
  --amber-t:rgba(224,168,0,.10);
  --amber-b:rgba(224,168,0,.40);
  /* layout */
  --measure:720px;   /* narrow prose column */
  --wide:960px;      /* figures / animations */
  --r:12px;          /* radius */
  --rhythm:48px;     /* vertical band rhythm */
  /* elevation */
  --sh:0 1px 2px rgba(0,0,0,.4),0 4px 16px rgba(0,0,0,.25);
  --sh-h:0 2px 6px rgba(0,0,0,.5),0 10px 30px rgba(0,0,0,.35);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:72px}
body{
  margin:0;background:var(--bg);color:var(--fg);
  font:16px/1.65 -apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
}

/* ---- layout shells ------------------------------------------------------- */
.wrap{max-width:var(--wide);margin:0 auto;padding:0 20px 80px}
.col{max-width:var(--measure);margin-inline:auto}          /* narrow prose    */
.bleed{max-width:var(--wide);margin-inline:auto}           /* wide figures    */

h1{font-size:30px;line-height:1.2;margin:0 0 10px;font-weight:750;letter-spacing:-.01em}
h2{font-size:21px;margin:0 0 14px;font-weight:700;letter-spacing:-.01em}
h3{font-size:16px;margin:0 0 6px;font-weight:700}
p{margin:0 0 12px}
a{color:var(--ac);text-decoration:none}
a:hover{text-decoration:underline}
code{background:#1c2230;border:1px solid var(--line);padding:.5px 6px;border-radius:6px;font-size:.88em}
.mut{color:var(--mut)}
.sub{color:var(--mut);font-size:14px;margin:0 0 18px}

/* section spacing rhythm: any element tagged .section gets vertical breathing */
.section{margin-top:var(--rhythm)}
.section--lg{margin-top:calc(var(--rhythm) + 8px)}

/* ---- nav ----------------------------------------------------------------- */
.nav{
  position:sticky;top:0;z-index:30;
  background:rgba(13,17,23,.72);backdrop-filter:blur(12px) saturate(140%);
  -webkit-backdrop-filter:blur(12px) saturate(140%);
  border-bottom:1px solid var(--line);
  margin:0 -20px 0;padding:11px 20px;
  display:flex;gap:6px;flex-wrap:wrap;align-items:center;
}
.nav .brand{font-weight:750;color:var(--fg);margin-right:10px;letter-spacing:-.01em}
.nav a{
  color:var(--mut);padding:6px 13px;border-radius:8px;
  font-weight:600;font-size:14px;transition:background .15s,color .15s;
}
.nav a:hover{color:var(--fg);background:#1c2230;text-decoration:none}
.nav a.on{color:#fff;background:var(--ac)}
.nav .spacer{flex:1}

/* ---- hero ---------------------------------------------------------------- */
.hero{padding:36px 0 8px}
.hero h1{max-width:var(--measure)}
.hero .claim-sub{color:var(--mut);font-size:15px;max-width:var(--measure);margin:0 0 22px}

.stats{display:flex;flex-wrap:wrap;gap:12px;margin:0 0 18px}
.statcard{
  flex:1 1 150px;min-width:140px;
  background:var(--panel);border:1px solid var(--line);border-radius:var(--r);
  padding:16px 16px 14px;box-shadow:var(--sh);
  transition:transform .15s,box-shadow .15s,border-color .15s;
}
.statcard:hover{transform:translateY(-2px);box-shadow:var(--sh-h);border-color:#3a4663}
.statcard .num{font-size:32px;line-height:1;font-weight:750;letter-spacing:-.02em;display:flex;align-items:baseline;gap:6px}
.statcard .num .glyph{font-size:20px}
.statcard.good .num{color:var(--ok)}
.statcard.open .num{color:var(--bad)}
.statcard.info .num{color:var(--ac)}
.statcard .lbl{margin-top:7px;font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--mut);font-weight:600}

.status{
  display:inline-flex;flex-wrap:wrap;gap:14px;align-items:center;
  font-size:14px;color:var(--mut);
  background:var(--panel);border:1px solid var(--line);border-radius:999px;
  padding:8px 16px;
}
.status .ok{color:var(--ok);font-weight:600}
.status .open{color:var(--bad);font-weight:600}

/* ---- the 5-band system --------------------------------------------------- */
.band{
  position:relative;
  border:1px solid var(--line);border-left-width:4px;
  border-radius:var(--r);
  background:var(--panel);box-shadow:var(--sh);
  padding:16px 20px;margin:14px 0;
  transition:box-shadow .15s,border-color .15s;
}
.band:hover{box-shadow:var(--sh-h)}
.tag{
  display:inline-block;font-size:10.5px;font-weight:700;letter-spacing:.1em;
  text-transform:uppercase;color:var(--mut);
  border:1px solid var(--line);border-radius:6px;
  padding:2px 8px;margin-bottom:9px;
}
.band .lead{font-size:18px;line-height:1.4;font-weight:700;margin:0;letter-spacing:-.005em}
.band .detail{font-size:14px;color:var(--mut);margin:6px 0 0}

/* per-kind accents (left rule + tag chip color) */
.band--intent{border-left-color:var(--mut)}
.band--intent .tag{color:var(--mut);border-color:var(--line)}

.band--hyp{border-left-color:var(--ac)}
.band--hyp .tag{color:#7cc4ff;border-color:rgba(0,114,178,.5);background:var(--ac-t)}

.band--method{border-left-color:var(--fg)}
.band--method .tag{color:var(--fg);border-color:#3a4663}

.band--result{border-left-color:var(--ok)}
.band--result .tag{color:#3ad6a6;border-color:rgba(0,158,115,.5);background:var(--ok-t)}

.band--why{
  border-left-color:var(--amber);border-color:var(--amber-b);
  background:linear-gradient(0deg,var(--amber-t),var(--amber-t)),var(--panel);
}
.band--why .tag{color:var(--amber);border-color:var(--amber-b);background:var(--amber-t)}
.band--why .lead{color:#f3dca0}

/* method band hosts the animation full-width */
.band--method .anim{margin-top:12px}

/* standalone WHY callout (alias of band--why for inline use) */
.why{
  border:1px solid var(--amber-b);border-left:4px solid var(--amber);
  border-radius:var(--r);
  background:linear-gradient(0deg,var(--amber-t),var(--amber-t)),var(--panel);
  padding:14px 18px;margin:14px 0;
  font-size:15px;line-height:1.5;color:#f3dca0;
}
.why b{color:var(--amber)}

/* ---- figures / animations ------------------------------------------------ */
.fig{margin:18px 0}
.fig img{
  display:block;max-width:100%;width:100%;height:auto;
  border:1px solid var(--line);border-radius:10px;background:#fff;
  box-shadow:var(--sh);
}
.fig .cap{color:var(--mut);font-size:13px;line-height:1.55;margin-top:9px;max-width:var(--measure)}
.fig .cap b{color:var(--fg)}
.figrow{display:grid;grid-template-columns:1fr 1fr;gap:16px}
@media(max-width:760px){.figrow{grid-template-columns:1fr}}

/* inline animated-svg holder (transparent, no white bg) */
.anim{
  border:1px solid var(--line);border-radius:10px;
  background:#0b0f15;box-shadow:var(--sh);overflow:hidden;
}
.anim svg{display:block;width:100%;height:auto}

/* ---- tables -------------------------------------------------------------- */
.tbl{width:100%;border-collapse:separate;border-spacing:0;font-size:14px;
  border:1px solid var(--line);border-radius:10px;overflow:hidden;box-shadow:var(--sh)}
.tbl th,.tbl td{padding:9px 12px;text-align:left;border-bottom:1px solid var(--line)}
.tbl thead th{background:#1c2230;font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--mut);font-weight:700}
.tbl tbody tr:last-child td{border-bottom:none}
.tbl tbody tr:hover{background:rgba(255,255,255,.02)}
.tbl td.num{text-align:right;font-variant-numeric:tabular-nums}
.tbl .win{color:var(--ok);font-weight:700}
.tbl .lose{color:var(--bad);font-weight:700}

/* ---- misc ---------------------------------------------------------------- */
.pill{display:inline-block;background:#1c2230;border:1px solid var(--line);
  border-radius:999px;padding:4px 12px;font-size:13px;margin:3px 4px 0 0;color:var(--mut)}
.cardlink{display:block;color:inherit}
.cardlink:hover{text-decoration:none}

@media(max-width:680px){
  h1{font-size:25px}
  .band .lead{font-size:16px}
  .statcard .num{font-size:27px}
  .wrap{padding:0 14px 64px}
  .nav{margin:0 -14px}
  .band{padding:14px 16px}
  .hero{padding:24px 0 4px}
}
@media(max-width:560px){
  .statcard{flex:1 1 100%}
  .tbl th,.tbl td{padding:7px 9px;font-size:13px}
  .status{border-radius:14px}
}