@font-face{font-family:Geist;src:local("Geist"),local("SF Pro Display"),local("Helvetica Neue")}
:root{--ink:#10110f;--paper:#f4f1e8;--yellow:#f1e529;--cyan:#49d8d0;--red:#ff5a4f;--line:rgba(244,241,232,.18);--muted:#a9aaa2}
*{box-sizing:border-box}
html{scroll-behavior:smooth;background:var(--ink)}
body{margin:0;background:var(--ink);color:var(--paper);font-family:Geist,Arial,sans-serif;letter-spacing:0;overflow-x:hidden}
button,input{font:inherit}
button{cursor:pointer}
main{overflow-x:hidden;width:100%;max-width:100%}
nav{height:64px;display:grid;grid-template-columns:1fr auto 1fr;align-items:center;padding:0 clamp(20px,4vw,64px);border-bottom:1px solid var(--line);position:relative;z-index:5}
.brand{color:var(--paper);text-decoration:none;font-weight:850;font-size:22px}.brand span{color:var(--yellow)}
.nav-copy{font-size:11px;font-weight:750;letter-spacing:.12em}
.engine-status{justify-self:end;color:var(--muted);font:700 11px/1.2 ui-monospace,SFMono-Regular,monospace}
.engine-status.ready{color:var(--cyan)}.engine-status.error{color:var(--red)}
.workbench{min-height:calc(100vh - 64px);display:grid;grid-template-columns:minmax(0,1.05fr) minmax(420px,.95fr);gap:clamp(36px,6vw,96px);padding:clamp(36px,7vh,80px) clamp(20px,4vw,64px) 52px;align-items:center;max-width:1600px;margin:auto}
.intro,.controls{min-width:0}
.kicker{font-size:11px;font-weight:800;letter-spacing:.18em;color:var(--yellow);margin:0 0 18px}
h1{font-size:clamp(2.6rem,5vw,5.4rem);line-height:.94;letter-spacing:0;max-width:1180px;margin:0;text-wrap:balance}
.lede{font-size:clamp(16px,1.45vw,21px);line-height:1.48;color:#c8c7bf;max-width:690px;margin:26px 0}
.source-note{display:grid;grid-template-columns:98px 1fr;gap:18px;align-items:center;max-width:690px;border-top:1px solid var(--line);padding-top:18px}
.source-note p{font-size:12px;line-height:1.5;color:var(--muted);margin:0}
.source-note strong{color:var(--paper)}
.source-image{width:98px;height:58px;background-image:linear-gradient(90deg,rgba(241,229,41,.25),rgba(16,17,15,.2)),url("https://picsum.photos/seed/reactor-core/320/180");background-size:cover;background-position:center;filter:grayscale(1) contrast(1.4);mix-blend-mode:luminosity;border-radius:999px}
.controls{background:var(--paper);color:var(--ink);padding:26px;border-radius:6px;box-shadow:0 28px 80px rgba(0,0,0,.35)}
.control-head{display:flex;align-items:center;justify-content:space-between;gap:12px;border-bottom:1px solid #ccc8bd;padding-bottom:16px;margin-bottom:18px}
.control-head h2,.equation-card h2,.sensitivity h2{font-size:17px;margin:0}
.text-button{border:0;background:transparent;text-decoration:underline;text-underline-offset:4px;font-size:12px;font-weight:750;color:var(--ink);padding:10px}
.field-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:13px}
.field-grid label{font-size:11px;font-weight:750;color:#4f504b;min-width:0}
.field-grid label:last-child{grid-column:1/-1}
.field-grid label span{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;border-bottom:2px solid #1d1e1b;margin-top:7px}
.field-grid input{width:100%;min-width:0;border:0;background:transparent;color:var(--ink);font-size:26px;font-weight:780;padding:6px 2px;outline:0}
.field-grid input:focus{background:#fffef8}
.field-grid b{font-size:11px;padding:0 5px;color:#676861}
.primary-button,.secondary-button,.reset-button{border:0;border-radius:4px;font-weight:800;min-height:48px}
.primary-button{width:100%;margin-top:20px;background:var(--yellow);color:var(--ink);display:flex;align-items:center;justify-content:space-between;padding:0 18px}
.primary-button:hover{filter:brightness(.94)}
.form-error{background:#ffe0dd;color:#8b160e;padding:10px 12px;margin-top:14px;font-size:12px;border-left:4px solid var(--red)}
.result-shell{border-top:1px solid var(--line);padding:72px clamp(20px,4vw,64px);max-width:1600px;margin:auto}
.empty-state{min-height:180px;display:grid;place-items:center;border:1px dashed rgba(244,241,232,.28);color:var(--muted);text-align:center;padding:30px}
.empty-state p{max-width:600px;font-size:18px;line-height:1.5}
.power-path{display:grid;grid-template-columns:auto 1fr auto 1fr auto 1fr auto 1fr auto;align-items:center;gap:12px;margin-bottom:20px;color:var(--yellow);font-size:10px;font-weight:850;letter-spacing:.14em}
.power-path i{height:2px;background:var(--yellow);transform-origin:left}
.result-grid{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));grid-auto-flow:dense;border-top:1px solid var(--line);border-left:1px solid var(--line)}
.result-grid article{border-right:1px solid var(--line);border-bottom:1px solid var(--line);padding:clamp(20px,3vw,36px);min-width:0;min-height:170px}
.result-hero{grid-column:span 7;background:var(--yellow);color:var(--ink)}
.equation-card{grid-column:span 5;background:#181916}
.result-grid article:nth-child(n+3){grid-column:span 4}
.result-hero>p:first-child{font-size:11px;font-weight:850;letter-spacing:.12em;margin:0}
.big-number{display:flex;align-items:flex-end;gap:12px;margin:20px 0 12px}.big-number strong{font-size:clamp(60px,9vw,120px);line-height:.72}.big-number span{font-size:18px;font-weight:750}
#decision-copy{max-width:650px;line-height:1.45;font-size:14px}
#equation-trace{font:600 12px/1.75 ui-monospace,SFMono-Regular,monospace;color:#d8d6cc;margin-top:18px}
#equation-trace div{display:flex;justify-content:space-between;gap:14px;border-bottom:1px solid #2f302c;padding:7px 0}
.metric-label{display:block;font-size:11px;font-weight:800;color:var(--muted);margin-bottom:28px}
.result-grid article>strong{display:block;font-size:clamp(22px,3vw,42px);line-height:1.1;overflow-wrap:anywhere}
.result-grid article small{display:block;color:var(--muted);margin-top:10px;line-height:1.4}
.n1-band{display:grid;grid-template-columns:minmax(250px,.7fr) minmax(0,1.3fr);gap:30px;padding:30px 0;border-bottom:1px solid var(--line);align-items:center}
.n1-band span{display:block;color:var(--cyan);font-size:10px;font-weight:850;letter-spacing:.15em;margin-bottom:9px}
.n1-band strong{font-size:clamp(18px,2.2vw,30px);overflow-wrap:anywhere}
.n1-band p{color:#c2c1b9;line-height:1.55;margin:0}
.sensitivity{padding:46px 0 0}.sensitivity header{display:flex;align-items:flex-end;justify-content:space-between;gap:25px;margin-bottom:24px}.sensitivity header p{color:var(--muted);margin:8px 0 0}
.secondary-button{background:var(--paper);color:var(--ink);padding:0 18px;white-space:nowrap}
.sensitivity-rows{border-top:1px solid var(--line)}
.s-row{display:grid;grid-template-columns:90px minmax(120px,1fr) 110px 140px;align-items:center;gap:18px;padding:15px 0;border-bottom:1px solid var(--line);font-size:13px}
.bar-track{height:10px;background:#282925;overflow:hidden}.bar-fill{height:100%;background:var(--cyan);transform-origin:left}
.s-row strong{text-align:right}.s-row span:last-child{text-align:right;color:var(--muted)}
.interpretation{min-height:80vh;background:var(--paper);color:var(--ink);padding:clamp(80px,14vw,190px) clamp(20px,4vw,64px);display:grid;grid-template-columns:minmax(230px,.65fr) minmax(0,1.35fr);gap:clamp(40px,9vw,150px)}
.sticky-word{font-size:11px;font-weight:850;letter-spacing:.15em;padding-top:8px}
.interpretation-copy{max-width:900px}.interpretation-copy>p{font-size:clamp(26px,4.2vw,62px);line-height:1.08;margin:0 0 80px}.interpretation-copy>p+P{font-size:clamp(20px,2vw,30px);color:#66675f}
details{border-top:2px solid var(--ink);border-bottom:2px solid var(--ink);padding:18px 0;margin:60px 0 28px}summary{font-weight:800;cursor:pointer}details p{line-height:1.6;max-width:720px}
.reset-button{background:var(--ink);color:var(--paper);padding:0 20px}
footer{padding:34px clamp(20px,4vw,64px);display:flex;justify-content:space-between;gap:24px;color:var(--muted);font-size:12px}footer a{color:var(--yellow)}
button:focus-visible,input:focus-visible,summary:focus-visible,a:focus-visible{outline:3px solid var(--cyan);outline-offset:3px}
@media(max-width:900px){
  nav{grid-template-columns:1fr auto}.nav-copy{display:none}
  .workbench{grid-template-columns:minmax(0,1fr);gap:30px;min-height:auto;padding-top:34px}
  h1{font-size:clamp(2.7rem,12vw,4.8rem)}
  .result-hero,.equation-card,.result-grid article:nth-child(n+3){grid-column:1/-1}
  .result-grid{grid-template-columns:minmax(0,1fr)}
  .n1-band,.interpretation{grid-template-columns:minmax(0,1fr)}
  .interpretation{min-height:auto}.interpretation-copy>p{margin-bottom:52px}
}
@media(max-width:560px){
  nav{height:54px;padding:0 16px}.engine-status{font-size:9px}
  .workbench{padding:24px 16px 38px}.kicker{margin-bottom:12px}.lede{margin:18px 0;font-size:15px}
  .source-note{grid-template-columns:70px 1fr}.source-image{width:70px;height:46px}
  .controls{padding:18px}.field-grid{gap:10px}.field-grid input{font-size:21px}
  .primary-button{margin-top:16px}
  .result-shell{padding:46px 16px}.power-path{gap:6px;font-size:8px}
  .result-grid article{min-height:138px;padding:20px}.big-number strong{font-size:72px}
  .n1-band{gap:14px}.sensitivity header{align-items:stretch;flex-direction:column}.secondary-button{width:100%}
  .s-row{grid-template-columns:62px minmax(0,1fr) 68px;gap:8px}.s-row span:last-child{display:none}
  .interpretation{padding:80px 16px}.interpretation-copy>p{font-size:28px}
  footer{flex-direction:column}
}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;animation:none!important;transition:none!important}}