/* The American Experiment — reusable exhibit system v1.0 */
:root{--ex-cream:#f3ecdc;--ex-ink:#171713;--ex-gold:#bd8b32;--ex-silver:#b9b8b0;--ex-red:#762d2b;--ex-blue:#162230;--ex-blue-deep:#0c131d;--ex-paper:#fffaf0;--ex-green:#45594a}
.exhibit-body{background:var(--ex-cream)}
.exhibit-progress{position:fixed;z-index:70;left:0;top:75px;width:100%;height:3px;background:rgba(0,0,0,.08)}.exhibit-progress span{display:block;height:100%;width:0;background:var(--ex-gold)}
.chapter-rail{position:fixed;z-index:40;right:14px;top:50%;transform:translateY(-50%);display:grid;gap:4px}.chapter-rail a{width:42px;min-height:36px;padding:7px 5px;display:grid;place-items:center;text-decoration:none;border:1px solid transparent;color:rgba(23,23,19,.42);background:rgba(243,236,220,.86);backdrop-filter:blur(7px)}.chapter-rail a span{font:700 10px var(--sans);letter-spacing:.08em}.chapter-rail a em{display:none}.chapter-rail a.active{color:var(--ex-ink);border-color:rgba(23,23,19,.2);background:var(--ex-paper)}
.exhibit-kicker{text-transform:uppercase;letter-spacing:.18em;font-size:11px;font-weight:700;color:var(--ex-red);margin:0 0 14px}.exhibit-hero{min-height:calc(100vh - 76px);display:flex;align-items:center;background:radial-gradient(circle at 78% 42%,rgba(189,139,50,.13),transparent 26%),linear-gradient(115deg,#f5efe3 0%,#ebe1ce 100%);border-bottom:1px solid rgba(23,23,19,.14);overflow:hidden}.exhibit-hero-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:70px;align-items:center;padding-top:72px;padding-bottom:72px}.exhibit-hero h1{font:400 clamp(54px,7vw,100px)/.98 var(--serif);letter-spacing:-.055em;margin:0;max-width:840px}.exhibit-subtitle{font:400 clamp(18px,2vw,25px)/1.5 var(--serif);color:#5a554d;margin:22px 0 30px}.question-plaque{border-left:3px solid var(--ex-gold);padding:4px 0 4px 20px;max-width:720px}.question-plaque small{display:block;text-transform:uppercase;letter-spacing:.14em;font-size:10px;margin-bottom:6px;color:#6a645c}.question-plaque strong{font:400 17px/1.55 var(--serif)}
.chapter{padding:100px 0;border-bottom:1px solid rgba(23,23,19,.14)}.chapter-heading{max-width:850px;margin-bottom:42px}.chapter-number{display:block;color:var(--ex-red);font-size:11px;font-weight:700;letter-spacing:.16em;text-transform:uppercase;margin-bottom:10px}.chapter-heading h2{font:400 clamp(40px,5vw,70px)/1.04 var(--serif);letter-spacing:-.04em;margin:0 0 14px}.chapter-deck{font:400 18px/1.65 var(--serif);color:#625c53;max-width:760px}
.exhibit-card{background:var(--ex-paper);border:1px solid rgba(23,23,19,.15);padding:clamp(20px,3vw,34px)}.artifact-grid,.comparison-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:22px}.artifact-card{background:var(--ex-paper);border:1px solid rgba(23,23,19,.15);overflow:hidden}.artifact-card img{display:block;width:100%;aspect-ratio:4/3;object-fit:cover}.artifact-card .artifact-copy{padding:22px}.artifact-meta{font-size:10px;letter-spacing:.14em;text-transform:uppercase;color:var(--ex-red);font-weight:700}
.primary-source{background:var(--ex-paper);border:1px solid rgba(23,23,19,.16);padding:clamp(24px,4vw,46px)}.primary-source header{border-bottom:1px solid rgba(23,23,19,.14);padding-bottom:16px;margin-bottom:20px}.primary-source blockquote{font:400 18px/1.8 var(--serif);margin:0}.source-context{color:#6b645a;font-size:14px}.source-question{margin-top:22px;padding:18px;border-left:3px solid var(--ex-gold);background:#f4ecdb}
.reasoning-chain{display:grid;grid-template-columns:repeat(5,1fr);gap:8px;align-items:stretch}.reasoning-chain>*{padding:16px 12px;background:var(--ex-paper);border:1px solid rgba(23,23,19,.14);font-size:13px}.reasoning-chain strong{display:block;color:var(--ex-red);text-transform:uppercase;letter-spacing:.08em;font-size:10px;margin-bottom:6px}
.interpretation-desk{display:grid;grid-template-columns:1fr 1fr;gap:20px}.interpretation-card{padding:28px;background:var(--ex-paper);border-top:4px solid var(--ex-blue)}.interpretation-card:nth-child(2){border-top-color:var(--ex-red)}
.historical-thinking{margin:34px 0;padding:24px 28px;background:var(--ex-blue);color:white}.historical-thinking small{color:#d8bd78;text-transform:uppercase;letter-spacing:.14em;font-weight:700}.historical-thinking p{margin-bottom:0;color:rgba(255,255,255,.8)}
.assignment-checkpoint{margin:44px 0 0;padding:24px 28px;border:1px solid rgba(23,23,19,.16);background:rgba(255,250,240,.72);display:grid;grid-template-columns:auto 1fr auto;gap:20px;align-items:center}.checkpoint-number{width:42px;height:42px;border-radius:50%;display:grid;place-items:center;background:var(--ex-ink);color:white;font:700 12px var(--serif)}
.reveal-on-scroll{opacity:0;transform:translateY(16px);transition:opacity .55s ease,transform .55s ease}.reveal-on-scroll.visible{opacity:1;transform:none}
button:focus-visible,a:focus-visible,[tabindex]:focus-visible{outline:3px solid var(--ex-gold);outline-offset:3px}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.reveal-on-scroll{opacity:1;transform:none;transition:none}}
@media(max-width:900px){.chapter-rail{display:none}.exhibit-hero-grid,.artifact-grid,.comparison-grid,.interpretation-desk{grid-template-columns:1fr}.reasoning-chain{grid-template-columns:1fr}.assignment-checkpoint{grid-template-columns:auto 1fr}.assignment-checkpoint>:last-child{grid-column:2}.chapter{padding:72px 0}}