:root{--ink:#0F172A;--ink2:#475569;--primary:#2563EB;--sky:#38BDF8;--canvas:#F5F8FC;--card:#FFFFFF;--line:#E8EEF5;--stat:#F1F5FA;--pos:#15803D;--posbg:#DCFCE7;--warn:#B45309;--warnbg:#FEF3C7;--frost:#1D4ED8;--frostbg:#E0ECFF}
@media(prefers-color-scheme:dark){:root{--ink:#F1F5F9;--ink2:#CBD5E1;--canvas:#0B1220;--card:#131C2E;--line:#24324A;--stat:#182238;--pos:#86EFAC;--posbg:#14532D;--warn:#FCD34D;--warnbg:#4A2E05;--frost:#BFDBFE;--frostbg:#1E3A8A}}
*{box-sizing:border-box}
body{margin:0;background:var(--canvas);color:var(--ink);font:16px/1.6 -apple-system,BlinkMacSystemFont,"SF Pro Text",Inter,system-ui,sans-serif;-webkit-font-smoothing:antialiased}
main{max-width:720px;margin:0 auto;padding:32px 20px 64px}main.wide{max-width:960px}
h1{font-size:34px;line-height:1.15;letter-spacing:-.02em;margin:0 0 8px}h2{font-size:22px;letter-spacing:-.01em;margin:36px 0 10px}h3{font-size:17px;margin:0}
.lede{font-size:18px;color:var(--ink2);margin:0 0 20px}
.muted{color:var(--ink2);font-size:14px}.small{font-size:13px}a{color:var(--primary)}
.card{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:18px;margin:16px 0}
footer{color:var(--ink2);font-size:13px;margin:40px auto;max-width:960px;padding:0 20px}
nav.top{display:flex;gap:18px;align-items:center;max-width:960px;margin:0 auto;padding:14px 20px;font-weight:600}
nav.top a{text-decoration:none;color:var(--ink2)}nav.top a.on,nav.top a:hover{color:var(--primary)}
nav.top .brand{display:flex;align-items:center;gap:8px;color:var(--ink);margin-right:auto;font-size:17px}nav.top img{border-radius:7px}
.hero{display:grid;grid-template-columns:1.2fr .8fr;gap:28px;align-items:center;padding:28px 0 8px}
.hero h1{font-size:44px}.hero .cta{display:inline-block;background:var(--primary);color:#fff;text-decoration:none;font-weight:700;border-radius:14px;padding:14px 22px;margin:14px 10px 0 0}
.hero .cta.ghost{background:var(--frostbg);color:var(--frost)}
.hero .art{display:flex;justify-content:center}.hero .art img{width:220px;height:220px;border-radius:48px;box-shadow:0 24px 60px rgba(37,99,235,.25)}
.pillars{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.pillars .card{margin:0}.pillars h3{margin-bottom:6px}
.promise{display:grid;grid-template-columns:repeat(2,1fr);gap:10px 24px;margin:0;padding:0;list-style:none}.promise li{padding-left:26px;position:relative}.promise li:before{content:"✓";position:absolute;left:0;color:var(--pos);font-weight:700}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(min(300px,100%),1fr));gap:14px}
.compound{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:16px}
.compound header{display:flex;justify-content:space-between;align-items:flex-start;gap:10px}.compound .purpose{color:var(--primary);font-weight:600;font-size:14px;margin:2px 0 0}.compound .muted{margin:2px 0 0}
.facts{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin:12px 0 10px}.facts div{background:var(--stat);border-radius:10px;padding:8px 10px}
.facts dt{font-size:10px;letter-spacing:.06em;text-transform:uppercase;color:var(--ink2);font-weight:600}.facts dd{margin:2px 0 0;font-size:13px;font-weight:600}
.grade{display:inline-block;border-radius:999px;padding:2px 9px;font-size:12px;font-weight:700;white-space:nowrap;line-height:18px}
.grade.sm{padding:0 6px;font-size:11px;margin-right:2px}
.gS{background:var(--posbg);color:var(--pos)}.gA{background:var(--primary);color:#fff}.gB{background:var(--frostbg);color:var(--frost)}.gC{background:var(--warnbg);color:var(--warn)}.gD{background:var(--stat);color:var(--ink2)}
.pill{display:inline-block;border-radius:999px;padding:1px 8px;font-size:11px;font-weight:700;vertical-align:middle}.pill.pop{background:var(--frostbg);color:var(--frost)}.pill.tag{background:var(--stat);color:var(--ink2)}
.note{background:var(--warnbg);color:var(--warn);border-radius:10px;padding:8px 10px;font-size:13px;margin:8px 0 0}
.rubric summary{cursor:pointer;list-style:none}.rubric summary::-webkit-details-marker{display:none}.rubric .grades{margin-right:10px}
.rubric-list{list-style:none;padding:0;margin:8px 0}.rubric-list li{display:flex;gap:12px;align-items:flex-start;padding:8px 0;border-top:1px solid var(--line)}
.toolbar{display:flex;flex-wrap:wrap;gap:10px;align-items:center;margin:18px 0 6px}
#q{flex:1 1 240px;font:inherit;padding:10px 14px;border-radius:12px;border:1px solid var(--line);background:var(--card);color:var(--ink)}
.chips{display:flex;flex-wrap:wrap;gap:6px}.chip{font:inherit;font-size:13px;font-weight:600;padding:6px 12px;border-radius:999px;border:1px solid var(--line);background:var(--card);color:var(--ink);cursor:pointer}.chip.on{background:var(--primary);border-color:var(--primary);color:#fff}
/* Mixer tool */
.tool{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:18px}.tool .card{margin:0}
label.f{display:block;font-size:13px;font-weight:600;color:var(--ink2);margin:12px 0 4px}label.f:first-child{margin-top:0}
.in{display:flex;flex-wrap:wrap;gap:8px;align-items:center}.in input{flex:1;font:inherit;font-size:20px;font-weight:700;padding:10px 12px;border-radius:12px;border:1px solid var(--line);background:var(--stat);color:var(--ink);min-width:0}
.seg{display:inline-flex;background:var(--stat);border-radius:12px;padding:3px}.seg button{font:inherit;font-size:14px;font-weight:600;border:0;background:transparent;color:var(--ink2);padding:7px 12px;border-radius:10px;cursor:pointer}.seg button.on{background:var(--card);color:var(--ink);box-shadow:0 1px 3px rgba(0,0,0,.12)}
.seg.wide{display:flex}.seg.wide button{flex:1;min-width:0;padding:7px 4px}
.hint{font-size:13px;color:var(--ink2);margin:6px 0 0}
.result{background:var(--frostbg);border-radius:16px;padding:16px;margin-top:4px}.result .k{font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--ink2);font-weight:700}
.result .big{font-size:40px;font-weight:800;letter-spacing:-.02em;font-variant-numeric:tabular-nums;line-height:1.1}.result .big small{font-size:18px;font-weight:600;color:var(--ink2);margin-left:6px}
.gauge{width:100%;height:auto;display:block;margin:10px 0 2px}
.math{margin-top:12px}.math summary{cursor:pointer;font-weight:600;color:var(--primary)}
.disclaimer{font-size:13px;color:var(--ink2);margin-top:14px}
.empty{color:var(--ink2)}
@media(max-width:720px){.hero{grid-template-columns:1fr}.hero h1{font-size:34px}.hero .art{order:-1}.hero .art img{width:140px;height:140px;border-radius:32px}.pillars,.tool,.promise{grid-template-columns:1fr}}
.card>:first-child{margin-top:0}.card>:last-child{margin-bottom:0}