/* ============================================================
   PURITY CHECK — bench-white instrument readout

   The palette derives from chromatography software on a lab
   bench: cold paper, instrument ink, one trace-green, one
   report-crimson. The point is that it should feel like a
   readout rather than a landing page, because the thing it is
   competing with for trust is a vendor's marketing.
   ============================================================ */

:root{
  --bench:#f3f6f6;
  --card:#ffffff;
  --ink:#0f171c;
  --ink-2:#5b6a72;
  --rule:#d8e2e2;
  --trace:#0b6e5b;
  --trace-lite:#e2f0eb;
  --flag:#c2183f;
  --flag-lite:#fbe7ec;
  --caution:#b26a00;
  --caution-lite:#fdf0dc;
  --focus:#1c5fd8;
  --trace-bg:#ffffff;
  --ev-bg:#f4f7f7;
  --head-bg:#fbfdfd;
  color-scheme: light;
}

/* A restrained dark theme. Same instrument, lights off. */
@media (prefers-color-scheme: dark){
  :root{
    --bench:#0d1417;
    --card:#141d21;
    --ink:#e8f0f0;
    --ink-2:#93a6ac;
    --rule:#243036;
    --trace:#4fd1ac;
    --trace-lite:#12332b;
    --flag:#ff6b8a;
    --flag-lite:#3a1220;
    --caution:#e0a44a;
    --caution-lite:#3a2a10;
    --focus:#6ea8ff;
    --trace-bg:#101a1e;
    --ev-bg:#0f181c;
    --head-bg:#111a1e;
    color-scheme: dark;
  }
}

*{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  background:var(--bench);
  color:var(--ink);
  font-family:'IBM Plex Sans',system-ui,-apple-system,sans-serif;
  line-height:1.55;
  -webkit-font-smoothing:antialiased;
  background-image:linear-gradient(var(--rule) 1px,transparent 1px),linear-gradient(90deg,var(--rule) 1px,transparent 1px);
  background-size:28px 28px;
  background-position:-1px -1px;
  overflow-wrap:break-word;
}
body.dragging::after{
  content:"drop it anywhere";
  position:fixed;inset:12px;z-index:200;
  border:3px dashed var(--focus);border-radius:8px;
  background:color-mix(in srgb,var(--focus) 8%,transparent);
  display:grid;place-items:center;
  font-family:'JetBrains Mono',monospace;font-size:15px;letter-spacing:.16em;
  text-transform:uppercase;color:var(--focus);pointer-events:none;
}
.wrap{max-width:940px;margin:0 auto;padding:0 20px}
a{color:inherit;text-underline-offset:2px}

.sr-only,.skip{
  position:absolute;width:1px;height:1px;overflow:hidden;
  clip:rect(0 0 0 0);white-space:nowrap;
}
.skip:focus{
  position:fixed;top:8px;left:8px;width:auto;height:auto;clip:auto;
  background:var(--ink);color:var(--card);padding:10px 14px;border-radius:4px;z-index:300;
}

.mono{font-family:'JetBrains Mono',ui-monospace,monospace}

/* ── top bar ── */
.bar{
  border-bottom:1px solid var(--rule);
  background:color-mix(in srgb,var(--bench) 90%,transparent);
  backdrop-filter:blur(8px);position:sticky;top:0;z-index:50;
}
.bar .wrap{display:flex;justify-content:space-between;align-items:center;padding:12px 20px;gap:12px}
.brand{font-family:'Archivo',sans-serif;font-weight:900;font-size:15px;letter-spacing:-.01em;display:flex;align-items:center;gap:8px}
.brand .dot{width:8px;height:8px;border-radius:50%;background:var(--trace);flex:none}
.bar .what{font-family:'JetBrains Mono',monospace;font-size:11px;color:var(--ink-2);letter-spacing:.04em}
@media(max-width:600px){.bar .what{display:none}}

/* ── hero ── */
.hero{padding:44px 0 8px}
h1{
  font-family:'Archivo',sans-serif;font-weight:900;
  font-size:clamp(38px,8.2vw,74px);line-height:.94;letter-spacing:-.035em;max-width:15ch;
}
h1 .q{color:var(--flag)}
.sub{font-size:clamp(15px,2.2vw,18px);color:var(--ink-2);max-width:58ch;margin-top:16px}
.sub b{color:var(--ink);font-weight:600}

/* ── the trace ── */
.scope{
  margin-top:26px;background:var(--card);border:1px solid var(--rule);
  border-radius:4px;overflow:hidden;
  box-shadow:0 1px 0 rgba(15,23,28,.04),0 12px 32px -18px rgba(15,23,28,.28);
}
.scope-head{
  display:flex;justify-content:space-between;align-items:center;gap:10px;
  padding:9px 14px;border-bottom:1px solid var(--rule);background:var(--head-bg);
}
.scope-head .t,.scope-head .s{font-family:'JetBrains Mono',monospace;font-size:10.5px;letter-spacing:.14em;text-transform:uppercase;color:var(--ink-2)}
.scope-head .s{color:var(--trace);display:flex;align-items:center;gap:6px;letter-spacing:.1em}
.scope-head .s::before{content:"";width:6px;height:6px;border-radius:50%;background:currentColor;animation:pulse 2.4s ease-in-out infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.25}}
#trace{display:block;width:100%;height:200px;--trace-bg:var(--trace-bg)}
@media(max-width:600px){#trace{height:158px}}

/* ── controls ── */
.dock{margin-top:18px;display:grid;grid-template-columns:1.35fr 1fr;gap:12px}
@media(max-width:720px){.dock{grid-template-columns:1fr}}
.btn{
  font-family:'Archivo',sans-serif;font-weight:800;font-size:16px;letter-spacing:-.01em;
  border:1.5px solid var(--ink);border-radius:4px;padding:16px 18px;
  background:var(--ink);color:var(--card);cursor:pointer;text-align:left;
  display:flex;align-items:center;gap:12px;
  transition:transform .12s ease,box-shadow .12s ease;
  box-shadow:0 2px 0 color-mix(in srgb,var(--ink) 90%,transparent);
}
.btn:hover{transform:translateY(-1px);box-shadow:0 4px 0 color-mix(in srgb,var(--ink) 90%,transparent)}
.btn:active{transform:translateY(1px);box-shadow:0 1px 0 color-mix(in srgb,var(--ink) 90%,transparent)}
.btn:focus-visible{outline:3px solid var(--focus);outline-offset:2px}
.btn.center{justify-content:center;margin-top:10px}
.btn .ic{font-size:20px;line-height:1}
.btn .sm{display:block;font-family:'IBM Plex Sans',sans-serif;font-weight:400;font-size:12px;opacity:.72;margin-top:2px}
.btn.ghost{background:var(--card);color:var(--ink);box-shadow:0 2px 0 var(--rule)}
.btn.ghost:hover{box-shadow:0 4px 0 var(--rule)}
.btn.ghost:active{box-shadow:0 1px 0 var(--rule)}

textarea{
  width:100%;min-height:150px;margin-top:12px;padding:14px;
  font-family:'JetBrains Mono',monospace;font-size:12.5px;line-height:1.6;
  border:1.5px solid var(--rule);border-radius:4px;background:var(--card);color:var(--ink);
  resize:vertical;
}
textarea:focus{outline:none;border-color:var(--focus);box-shadow:0 0 0 3px color-mix(in srgb,var(--focus) 18%,transparent)}
textarea::placeholder{color:var(--ink-2);opacity:.7}
.hidden{display:none!important}

.samples{margin-top:12px;display:flex;gap:8px;flex-wrap:wrap;align-items:center}
.samples .lab{font-family:'JetBrains Mono',monospace;font-size:11px;color:var(--ink-2);letter-spacing:.08em;text-transform:uppercase}
.chip{
  font-family:'JetBrains Mono',monospace;font-size:11.5px;font-weight:500;
  border:1px solid var(--rule);background:var(--card);color:var(--ink);
  padding:6px 11px;border-radius:100px;cursor:pointer;transition:border-color .12s,color .12s;
}
.chip:hover{border-color:var(--ink)}
.chip:focus-visible{outline:2px solid var(--focus);outline-offset:2px}
.chip.bad:hover{border-color:var(--flag);color:var(--flag)}
.chip.good:hover{border-color:var(--trace);color:var(--trace)}

.status{margin-top:12px;font-family:'JetBrains Mono',monospace;font-size:12px;color:var(--ink-2);min-height:18px}
.status b{color:var(--ink)}

/* ── disclosure ── */
details.exp{margin-top:12px;border:1px solid var(--rule);border-radius:4px;background:var(--card)}
details.exp summary{
  padding:13px 15px;cursor:pointer;font-weight:600;font-size:14px;list-style:none;
  display:flex;justify-content:space-between;align-items:center;gap:10px;
}
details.exp summary::-webkit-details-marker{display:none}
details.exp summary::after{content:"+";font-family:'JetBrains Mono',monospace;color:var(--ink-2);font-size:16px}
details.exp[open] summary::after{content:"–"}
details.exp summary:focus-visible{outline:2px solid var(--focus);outline-offset:-2px}
.exp-body{padding:0 15px 15px;font-size:13.5px;color:var(--ink-2);max-width:70ch}
.exp-body p{margin-bottom:9px}
.exp-body p:last-child{margin-bottom:0}
.exp-body b{color:var(--ink)}

/* ── verdict ── */
#out{margin-top:34px}
.verdict{
  background:var(--card);border:1.5px solid var(--ink);border-radius:5px;overflow:hidden;
  box-shadow:0 18px 40px -24px rgba(15,23,28,.4);
}
.v-top{padding:22px;border-bottom:1px solid var(--rule);display:flex;gap:22px;align-items:center}
@media(max-width:720px){.v-top{flex-direction:column;align-items:flex-start;gap:14px;padding:18px}}
.dials{display:flex;gap:14px;align-items:center;flex:none}
.dial{position:relative;flex:none;width:118px;height:118px}
.dial.small{width:92px;height:92px}
.dial svg{transform:rotate(-90deg)}
.dial-arc{transition:stroke-dashoffset 1.1s cubic-bezier(.2,.8,.2,1)}
.dial .num{
  position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;
  font-family:'Archivo',sans-serif;font-weight:900;font-size:32px;letter-spacing:-.04em;line-height:1;
}
.dial.small .num{font-size:24px}
.dial .num small{font-family:'JetBrains Mono',monospace;font-size:8.5px;font-weight:500;letter-spacing:.12em;color:var(--ink-2);margin-top:3px;text-transform:uppercase}
.v-head{flex:1}
.v-head .band{font-family:'JetBrains Mono',monospace;font-size:11px;letter-spacing:.18em;text-transform:uppercase;font-weight:700}
.v-head h2{font-family:'Archivo',sans-serif;font-weight:900;font-size:clamp(24px,4.6vw,34px);line-height:1.02;letter-spacing:-.03em;margin:5px 0 7px}
.v-head p{font-size:14px;color:var(--ink-2);max-width:52ch}

.twoscore{padding:12px 22px;border-bottom:1px solid var(--rule);background:var(--head-bg)}
.twoscore p{font-size:12.5px;color:var(--ink-2);max-width:82ch;line-height:1.6}
.twoscore b{color:var(--ink);font-weight:600}
@media(max-width:600px){.twoscore{padding:12px 16px}}

.tally{display:flex;border-bottom:1px solid var(--rule);background:var(--head-bg);flex-wrap:wrap}
.tally div{flex:1;min-width:88px;padding:13px 14px;border-right:1px solid var(--rule);text-align:center}
.tally div:last-child{border-right:none}
.tally .n{font-family:'Archivo',sans-serif;font-weight:900;font-size:22px;letter-spacing:-.03em;display:block}
.tally .l{font-family:'JetBrains Mono',monospace;font-size:9.5px;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-2);margin-top:2px;display:block}

.cat{padding:18px 22px 4px}
@media(max-width:600px){.cat{padding:16px 16px 4px}}
.cat h3{
  font-family:'JetBrains Mono',monospace;font-size:10.5px;letter-spacing:.16em;text-transform:uppercase;
  color:var(--ink-2);font-weight:500;display:flex;align-items:center;gap:10px;margin-bottom:10px;
}
.cat h3::after{content:"";flex:1;height:1px;background:var(--rule);order:1}
.cat .cat-n{order:2;font-size:10px;letter-spacing:.08em}
.find{display:flex;gap:12px;padding:11px 0;border-bottom:1px dashed var(--rule);align-items:flex-start}
.find:last-child{border-bottom:none}
.find.sig{background:var(--flag-lite);margin:0 -10px;padding:11px 10px;border-radius:3px}
.mark{
  flex:none;width:22px;height:22px;border-radius:3px;display:grid;place-items:center;
  font-family:'JetBrains Mono',monospace;font-weight:700;font-size:12px;margin-top:1px;
}
.mark.pass{background:var(--trace-lite);color:var(--trace)}
.mark.fail{background:var(--flag-lite);color:var(--flag)}
.mark.warn{background:var(--caution-lite);color:var(--caution)}
.find .txt{flex:1;min-width:0}
.find .ttl{font-weight:600;font-size:13.5px;line-height:1.4;display:block}
.sigmark{
  font-family:'JetBrains Mono',monospace;font-size:9px;font-weight:700;letter-spacing:.14em;
  text-transform:uppercase;background:var(--flag);color:var(--card);
  padding:2px 5px;border-radius:2px;vertical-align:2px;margin-right:4px;
}
.find .why{font-size:12.5px;color:var(--ink-2);margin-top:3px;line-height:1.5;display:block}
.find .ev{
  margin-top:6px;font-family:'JetBrains Mono',monospace;font-size:11.5px;display:block;
  background:var(--ev-bg);border-left:2px solid var(--rule);padding:5px 9px;border-radius:0 3px 3px 0;
  color:var(--ink);word-break:break-word;
}
.find.fail .ev{border-left-color:var(--flag)}
.find.warn .ev{border-left-color:var(--caution)}
.find .wt{font-family:'JetBrains Mono',monospace;font-size:10px;color:var(--ink-2);flex:none;letter-spacing:.06em;padding-top:3px;cursor:help}

.act{margin:14px 22px 22px;border:1.5px solid var(--ink);border-radius:4px;overflow:hidden}
@media(max-width:600px){.act{margin:14px 16px 18px}}
.act-h{padding:9px 14px;background:var(--ink);color:var(--card);font-family:'JetBrains Mono',monospace;font-size:10.5px;letter-spacing:.16em;text-transform:uppercase;font-weight:500}
.act-b{padding:14px;font-size:13.5px;background:var(--card)}
.act-b ul{margin:0;padding-left:18px}
.act-b li{margin-bottom:6px}
.act-b li:last-child{margin-bottom:0}
.act-b textarea{min-height:0;height:auto;margin-top:0;background:var(--ev-bg);field-sizing:content}
.act-b .btn{margin-top:10px;justify-content:center;font-size:14px;padding:11px;width:100%}

.exports{display:flex;gap:10px;flex-wrap:wrap;margin:0 22px 22px}
@media(max-width:600px){.exports{margin:0 16px 18px}}
.exports .btn{font-size:14px;padding:12px 16px;flex:1;min-width:160px;justify-content:center;text-align:center}

/* ── standing sections ── */
.limits,.history{
  margin-top:22px;border:1.5px dashed var(--rule);border-radius:4px;background:var(--card);padding:18px 20px;
}
.limits h3,.history h3{font-family:'Archivo',sans-serif;font-weight:800;font-size:17px;letter-spacing:-.02em;margin-bottom:8px}
.limits p,.history p{font-size:13.5px;color:var(--ink-2);max-width:70ch;margin-bottom:8px}
.limits p:last-child,.history p:last-child{margin-bottom:0}
.limits b,.history b{color:var(--ink)}
.hist-count{font-family:'JetBrains Mono',monospace;font-size:12px;color:var(--ink)!important;letter-spacing:.04em}
.hist-actions{display:flex;gap:8px;margin-top:12px;flex-wrap:wrap}

.faq{margin-top:40px}
.faq h2{font-family:'Archivo',sans-serif;font-weight:900;font-size:clamp(24px,4.5vw,32px);letter-spacing:-.03em;margin-bottom:14px}

footer{margin-top:48px;padding:26px 0 60px;border-top:1px solid var(--rule)}
footer p{font-family:'JetBrains Mono',monospace;font-size:11.5px;color:var(--ink-2);line-height:1.9}
footer b{color:var(--ink)}

@media(prefers-reduced-motion:reduce){
  *{animation:none!important;transition:none!important;scroll-behavior:auto!important}
}
@media print{
  .bar,.dock,.samples,.scope,.exports,.status,#ta,#runBtn,.history{display:none!important}
  body{background:#fff;color:#000}
  .verdict{box-shadow:none;border-color:#000}
}