/* Binaural Waves — shared design system.
   Concept: an instrument for sound. Nocturnal, quiet, precise.
   Two channels (warm / cool) whose interference is the "beat". */

:root{
  --ink:#070912;          /* ground, near-black blue */
  --ink-2:#0B0F1E;        /* raised surface */
  --ink-3:#111629;        /* cards */
  --paper:#EDEFF7;        /* primary text, cool white */
  --muted:#797F97;        /* cool grey, biased to accent */
  --faint:#525873;
  --line:rgba(255,255,255,.075);
  --line-2:rgba(255,255,255,.14);
  --sig:#9DB4FF;          /* signal / interactive (calm periwinkle) */
  --warm:#E8C079;         /* left channel */
  --cool:#78B0E6;         /* right channel */
  --caution:#E8B36A;
  --mono:ui-monospace,"SF Mono",SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;
  --sans:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --wrap:1080px;
}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;background:var(--ink);color:var(--paper);
  font-family:var(--sans);font-size:17px;line-height:1.7;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
  background-image:
    radial-gradient(120% 60% at 50% -10%,rgba(120,176,230,.08),transparent 60%),
    linear-gradient(180deg,#080A14,#070912 40%);
  background-attachment:fixed;
}
a{color:var(--sig);text-decoration:none}
a:hover{text-decoration:underline;text-underline-offset:3px}
::selection{background:rgba(157,180,255,.25)}

.wrap{max-width:var(--wrap);margin:0 auto;padding:0 26px}

/* ---- eyebrow / mono labels ---- */
.eyebrow{font-family:var(--mono);font-size:12px;letter-spacing:.22em;
  text-transform:uppercase;color:var(--sig);margin:0 0 14px}
.mono{font-family:var(--mono);font-variant-numeric:tabular-nums}

/* ---- top bar ---- */
.topbar{position:sticky;top:0;z-index:30;
  background:rgba(7,9,18,.72);backdrop-filter:blur(14px);
  border-bottom:1px solid var(--line)}
.topbar .row{display:flex;align-items:center;justify-content:space-between;
  max-width:var(--wrap);margin:0 auto;padding:15px 26px}
.brand{display:inline-flex;align-items:center;gap:11px;color:var(--paper);
  font-weight:600;font-size:17px;letter-spacing:-.01em}
.brand em{font-style:normal;color:var(--muted);font-weight:500}
.brand:hover{text-decoration:none}
.brand .mark{width:26px;height:18px;display:block;flex:none}
.topnav a{color:var(--muted);font-size:14.5px;margin-left:26px}
.topnav a:hover{color:var(--paper);text-decoration:none}
@media(max-width:560px){.topnav a{margin-left:18px;font-size:13.5px}}

/* ---- buttons ---- */
.btn{display:inline-flex;align-items:center;gap:9px;font-weight:600;font-size:15.5px;
  padding:13px 22px;border-radius:11px;border:1px solid transparent;cursor:pointer;
  font-family:var(--sans)}
.btn-primary{background:var(--sig);color:#0A0E1C}
.btn-primary:hover{background:#B4C6FF;text-decoration:none}
.btn-ghost{background:transparent;border-color:var(--line-2);color:var(--paper)}
.btn-ghost:hover{border-color:var(--sig);color:#fff;text-decoration:none}

/* ---- footer ---- */
.footer{border-top:1px solid var(--line);margin-top:96px;
  background:linear-gradient(180deg,transparent,rgba(120,176,230,.03))}
.footer .grid{display:grid;grid-template-columns:1.4fr 1fr;gap:40px;
  max-width:var(--wrap);margin:0 auto;padding:46px 26px 56px}
.footer .tag{color:var(--muted);font-size:14px;max-width:34ch;margin:14px 0 0}
.fnav{display:flex;flex-wrap:wrap;gap:8px 20px;margin-top:20px}
.fnav a{color:var(--muted);font-size:14px}
.fnav a:hover{color:var(--paper)}
.legal{font-family:var(--mono);font-size:12.5px;line-height:2;color:var(--faint);
  border:1px solid var(--line);border-radius:12px;padding:16px 18px}
.legal a{color:var(--muted)}
@media(max-width:640px){.footer .grid{grid-template-columns:1fr;gap:26px}}

/* ---- document pages ---- */
.doc{max-width:720px;margin:0 auto;padding:64px 26px 20px}
.doc h1{font-size:clamp(30px,5vw,40px);line-height:1.08;letter-spacing:-.025em;
  font-weight:700;margin:0 0 10px}
.doc .updated{font-family:var(--mono);font-size:12.5px;color:var(--faint);
  letter-spacing:.04em;margin:0 0 8px}
.prose{margin-top:20px}
.prose h2{font-size:15px;font-weight:700;letter-spacing:-.01em;color:#fff;
  margin:40px 0 10px;padding-top:26px;border-top:1px solid var(--line)}
.prose h2:first-of-type{border-top:0;padding-top:0}
.prose p,.prose li{color:#C7CBDC;font-size:16px}
.prose strong{color:var(--paper)}
.prose ul{padding-left:20px;margin:10px 0}
.prose li{margin:7px 0}
.prose a{color:var(--sig)}
.lead{color:var(--muted);font-size:17px}
.callout{background:rgba(232,179,106,.07);border:1px solid rgba(232,179,106,.28);
  border-radius:14px;padding:18px 20px;margin:18px 0}
.callout h2{border:0;padding-top:6px;margin-top:0;color:var(--caution)}
.callout p,.callout li{color:#E7DAC1}
.reqbox{font-family:var(--mono);font-size:12.5px;line-height:2;color:var(--muted);
  border:1px solid var(--line);border-radius:12px;padding:16px 18px;margin-top:20px}
.reqbox a{color:var(--sig)}