:root{--bg:#0f1115;--card:#171a21;--line:#262b36;--fg:#e8ebf1;--mute:#9aa3b2;--acc:#ff7a1a;--acc2:#ffa45c;--r:14px}
*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}
body{margin:0;font:16px/1.6 system-ui,-apple-system,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--fg)}
a{color:var(--acc2)}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid var(--acc);outline-offset:2px}
.wrap{max-width:1100px;margin:0 auto;padding:0 20px}
.skip{position:absolute;left:-999px}.skip:focus{left:10px;top:10px;background:#000;padding:8px;z-index:9}
header.site{border-bottom:1px solid var(--line)}header.site .wrap{display:flex;align-items:center;justify-content:space-between;height:60px}
.brand{font-weight:800;font-size:20px;color:var(--fg);text-decoration:none;display:flex;gap:8px;align-items:center}.brand span span{color:var(--acc)}input[type=range]{accent-color:var(--acc)}
nav a{color:var(--mute);text-decoration:none;margin-left:18px}nav a:hover{color:var(--fg)}
.hero{padding:56px 0 28px}.hero h1{font-size:clamp(30px,5vw,48px);line-height:1.15;margin:0 0 12px}.hero p{color:var(--mute);font-size:18px;max-width:640px;margin:0}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:16px;padding:24px 0 48px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:20px;text-decoration:none;color:var(--fg);display:block;transition:border-color .15s,transform .15s}
a.card:hover{border-color:var(--acc);transform:translateY(-2px)}.card h2,.card h3{font-size:17px;margin:0 0 6px}.card p{color:var(--mute);font-size:14px;margin:0}
.badge{display:inline-block;font-size:12px;padding:2px 8px;border-radius:99px;margin-bottom:10px;background:#2a2f3a;color:var(--mute)}.badge.live{background:#ff7a1a22;color:var(--acc2)}
.soon{opacity:.6}
.ad-slot{border:2px dashed #3a4150;border-radius:var(--r);color:#6b7383;text-align:center;padding:22px;margin:24px 0;font-size:13px;min-height:90px;display:flex;align-items:center;justify-content:center}
footer.site{border-top:1px solid var(--line);color:var(--mute);font-size:14px;padding:28px 0;margin-top:40px}footer.site a{color:var(--mute);margin-right:16px}
.prose{max-width:760px}.prose h2{margin-top:36px}.prose code,.formula{background:#1d212a;padding:2px 6px;border-radius:6px}
.formula{display:block;padding:12px;overflow-x:auto;font-family:ui-monospace,monospace;font-size:14px}
/* tool */
.tool{display:grid;grid-template-columns:1.4fr 1fr;gap:20px}@media(max-width:860px){.tool{grid-template-columns:1fr}}
.viewer{position:relative;background:#12151b;border:1px solid var(--line);border-radius:var(--r);min-height:420px;overflow:hidden}
.viewer canvas{display:block;width:100%;height:100%;touch-action:none}
.drop{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;text-align:center;padding:20px;color:var(--mute);border:2px dashed transparent;border-radius:var(--r)}
.drop.over{border-color:var(--acc);background:#ff7a1a10}.drop.hidden{display:none}
.btn{background:var(--acc);color:#111;border:0;border-radius:10px;padding:10px 16px;font-weight:700;cursor:pointer;font-size:15px}.btn.ghost{background:#2a2f3a;color:var(--fg)}
.panel{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:18px}
.panel label{display:block;font-size:13px;color:var(--mute);margin:10px 0 4px}
.panel input,.panel select{width:100%;background:#0f1115;border:1px solid var(--line);color:var(--fg);border-radius:8px;padding:8px 10px;font-size:15px}
.row{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.results{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:14px}.stat{background:#0f1115;border-radius:10px;padding:10px}.stat b{display:block;font-size:22px;color:var(--fg)}.stat span{font-size:12px;color:var(--mute)}
.stat.big{grid-column:1/-1}.stat.big b{color:var(--acc2);font-size:28px}
.err{color:#ff8080;font-size:14px}.muted{color:var(--mute);font-size:13px}
table{border-collapse:collapse;width:100%}td,th{border-bottom:1px solid var(--line);padding:6px 8px;text-align:left;font-size:14px}
details{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:12px 16px;margin:10px 0}summary{cursor:pointer;font-weight:600}
.quote td input{width:100%;min-width:50px;background:#0f1115;border:1px solid var(--line);color:var(--fg);border-radius:6px;padding:5px}
.qwrap{overflow-x:auto}
pre.gc{background:#0f1115;padding:10px;border-radius:8px;font-size:14px}
#consent{position:fixed;left:12px;right:12px;bottom:12px;max-width:640px;margin:auto;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:14px 16px;z-index:50;box-shadow:0 8px 30px #0008;font-size:14px}
#consent p{margin:0 0 10px;color:var(--mute)}#consent .btn{padding:8px 14px;font-size:14px;margin-right:8px}
@media print{header.site,footer.site,.ad-slot,.noprint,#consent,.hero p{display:none!important}body{background:#fff;color:#000}.panel{border:0;background:#fff;color:#000}.quote td input{border:0;color:#000;background:#fff}}
.gear{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:4px 18px 10px;margin-top:32px}.gear h2{font-size:18px}.gear ul{padding-left:18px}.gear li{margin:6px 0}
/* ---- design upgrade ---- */
:root{--card:#151920;--card2:#1a1f28;--line:#252b37;--shadow:0 1px 0 #ffffff08 inset,0 10px 30px -12px #000a}
body{font:16px/1.65 Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;letter-spacing:-.005em;background:radial-gradient(1200px 500px at 80% -10%,#ff7a1a14,transparent 60%),var(--bg)}
h1,h2,h3{letter-spacing:-.02em;line-height:1.2}h2{font-size:clamp(20px,2.6vw,26px)}
header.site{position:sticky;top:0;z-index:20;background:#0f1115cc;backdrop-filter:saturate(1.4) blur(10px);-webkit-backdrop-filter:saturate(1.4) blur(10px)}
nav a{font-weight:500}nav a:hover{color:var(--acc2)}
.hero h1{font-weight:800}.hero h1 em{font-style:normal;background:linear-gradient(90deg,var(--acc),var(--acc2));-webkit-background-clip:text;background-clip:text;color:transparent}
.hero.home{display:grid;grid-template-columns:1.1fr .9fr;gap:24px;align-items:center;padding:48px 0 20px}
.eyebrow{display:inline-block;font-size:13px!important;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--acc2)!important;margin:0 0 14px!important}
.hero-copy>p:not(.eyebrow){max-width:560px}.cta{display:flex;gap:10px;flex-wrap:wrap;margin-top:22px}.cta .btn{text-decoration:none;display:inline-block}
.hero-art{position:relative;aspect-ratio:1/1;max-height:440px;width:100%;justify-self:center}
.hero-fallback,.hero-canvas{position:absolute;inset:0;width:100%;height:100%}.hero-canvas{opacity:0;transition:opacity .8s}.hero-art.live .hero-canvas{opacity:1}.hero-art.live .hero-fallback{opacity:0;transition:opacity .8s}
@media(max-width:860px){.hero.home{grid-template-columns:1fr;padding-top:28px}.hero-art{max-height:220px;aspect-ratio:16/9;order:-1}}
.btn{transition:transform .12s,box-shadow .2s,background .2s;box-shadow:0 6px 20px -8px #ff7a1a88}.btn:hover{transform:translateY(-1px);background:#ff8a33}.btn.ghost{box-shadow:none;border:1px solid var(--line)}.btn.ghost:hover{background:#323846}
.card{position:relative;background:linear-gradient(180deg,var(--card2),var(--card));box-shadow:var(--shadow);padding:22px;overflow:hidden}
.card::after{content:"";position:absolute;inset:0;border-radius:inherit;pointer-events:none;background:radial-gradient(400px 140px at var(--mx,50%) 0%,#ff7a1a1c,transparent 70%);opacity:0;transition:opacity .25s}
a.card:hover{border-color:#ff7a1a99;transform:translateY(-3px);box-shadow:var(--shadow),0 18px 40px -18px #ff7a1a55}a.card:hover::after{opacity:1}
.card .ico{display:block;width:40px;height:40px;padding:8px;margin-bottom:14px;border-radius:11px;background:#ff7a1a14;border:1px solid #ff7a1a33;color:#cfd5df;transition:color .2s,background .2s}
.ico .a{stroke:var(--acc)}a.card:hover .ico{color:#fff;background:#ff7a1a26}
.card h3{font-size:16.5px;margin-bottom:6px}.card p{line-height:1.5}
.grid{gap:18px}
.panel,.viewer{box-shadow:var(--shadow)}.panel{background:linear-gradient(180deg,var(--card2),var(--card))}
.stat{background:#0d1014;border:1px solid #1f242e;border-radius:12px;padding:12px 14px}.stat span{text-transform:uppercase;letter-spacing:.06em;font-size:11px;font-weight:600}
.stat b{font-variant-numeric:tabular-nums;letter-spacing:-.01em;margin-top:2px}.stat.big{background:linear-gradient(180deg,#ff7a1a12,#0d1014);border-color:#ff7a1a33}
.panel input,.panel select{transition:border-color .15s}.panel input:hover,.panel select:hover{border-color:#3a4252}
.prose p,.prose li{color:#cfd5df}.prose h2{margin-top:44px}
details{transition:border-color .2s}details[open]{border-color:#ff7a1a55}summary::marker{color:var(--acc)}
table{font-variant-numeric:tabular-nums}th{color:var(--mute);font-weight:600;font-size:13px}
@media(prefers-reduced-motion:reduce){*{transition:none!important}a.card:hover{transform:none}}