:root{
  --ink:#18202a;
  --muted:#687281;
  --paper:#f6f7f9;
  --card:#fff;
  --brain:#6d0014;
  --brain-dark:#40000c;
  --gold:#ffd500;
  --left:rgba(23,122,154,.58);
  --right:rgba(170,50,80,.55);
  --third:rgba(218,161,41,.50);
  --fourth:rgba(70,153,96,.45);
  --line:#dde1e7;
  --shadow:0 18px 50px rgba(28,35,44,.09);
}
*{box-sizing:border-box}
body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:linear-gradient(180deg,#fff 0,#f5f6f8 46%,#fff 100%)}
.site-header{min-height:250px;padding:54px max(6vw,28px);display:flex;gap:28px;align-items:center;color:#fff;background:radial-gradient(circle at 85% 15%,rgba(255,213,0,.24),transparent 24%),linear-gradient(120deg,var(--brain-dark),var(--brain) 72%,#920029)}
.brand-mark{width:92px;height:92px;flex:0 0 auto;background:#690010;border:1px solid rgba(255,255,255,.25);position:relative;box-shadow:0 15px 40px rgba(0,0,0,.25)}
.brand-mark span{width:16px;height:16px;border-radius:50%;background:var(--gold);position:absolute}
.brand-mark span:nth-child(1){left:18px;top:22px}
.brand-mark span:nth-child(2){right:16px;top:16px}
.brand-mark span:nth-child(3){right:18px;bottom:19px}
.brand-mark span:nth-child(4){left:25px;bottom:22px}
.brand-mark:before,.brand-mark:after{content:"";position:absolute;height:3px;background:var(--gold);transform-origin:left center}
.brand-mark:before{width:45px;left:27px;top:32px;transform:rotate(-13deg)}
.brand-mark:after{width:44px;left:34px;top:55px;transform:rotate(24deg)}
.eyebrow{margin:0 0 9px;text-transform:uppercase;letter-spacing:.15em;font-size:.74rem;font-weight:800;opacity:.82}
h1{font-family:Georgia,serif;font-size:clamp(2rem,4vw,4.25rem);line-height:1.02;margin:0;max-width:1000px}
.lead{max-width:920px;font-size:1.08rem;line-height:1.65;margin:18px 0 0;color:rgba(255,255,255,.83)}
main{width:min(1480px,92vw);margin:0 auto}
.selector-panel,.comparison-shell,.method-section{padding:56px 0}
.section-heading{display:flex;align-items:end;justify-content:space-between;gap:24px;margin-bottom:24px}
.section-heading h2,.method-section h2{font-family:Georgia,serif;font-size:clamp(1.75rem,2.8vw,2.7rem);margin:0}
.selection-row{display:flex;align-items:center;justify-content:space-between;gap:18px;margin:-10px 0 22px}
.selection-row p{margin:0;color:var(--muted)}
.selection-status{padding:8px 12px;border-radius:999px;background:#eef8f3;color:#1c6b45;font-weight:700;font-size:.9rem;white-space:nowrap}

.article-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}
.article-option{border:1px solid var(--line);border-radius:18px;background:var(--card);padding:20px;box-shadow:0 8px 25px rgba(30,38,48,.04);cursor:pointer;transition:.2s ease;position:relative;min-height:245px}
.article-option:hover{transform:translateY(-3px);box-shadow:var(--shadow)}
.article-option.selected{border-color:var(--brain);box-shadow:0 0 0 3px rgba(109,0,20,.1),var(--shadow)}
.article-option input{position:absolute;right:18px;top:18px;width:20px;height:20px;accent-color:var(--brain)}
.article-number{font-size:.75rem;font-weight:900;letter-spacing:.12em;color:var(--brain);text-transform:uppercase}
.article-option h3{font-family:Georgia,serif;font-size:1.18rem;line-height:1.28;margin:18px 34px 10px 0}
.article-option p{color:var(--muted);line-height:1.5;font-size:.92rem}
.meta-row{display:flex;gap:8px;flex-wrap:wrap;margin-top:14px}
.tag{font-size:.72rem;padding:5px 8px;border-radius:999px;background:#f1f3f5;color:#4b5664;font-weight:700}
.comparison-shell{border-top:1px solid var(--line)}
.ghost-button{border:1px solid #cfd4db;background:#fff;border-radius:10px;padding:10px 14px;font-weight:750;cursor:pointer}
.ghost-button:hover{border-color:var(--brain);color:var(--brain)}
.ghost-button:disabled{opacity:.45;cursor:not-allowed}
.dimension-tabs{display:flex;gap:8px;flex-wrap:wrap;margin:-5px 0 20px}
.dimension-tab{border:1px solid var(--line);background:#fff;border-radius:999px;padding:9px 13px;font-weight:750;color:#56616f;cursor:pointer}
.dimension-tab.active{background:#eee2e5;border-color:#d4a8b2;color:var(--brain)}
.comparison-layout{display:grid;grid-template-columns:minmax(0,1.65fr) minmax(320px,.8fr);gap:22px;align-items:start}
.venn-card,.details-panel{background:#fff;border:1px solid var(--line);border-radius:22px;box-shadow:var(--shadow)}
.venn-card{padding:12px}
.diagram-wrap svg{display:block;width:100%;height:auto}
.hidden{display:none}
.venn-circle{stroke-width:3}
.venn-circle.left,.circle-a{fill:var(--left);stroke:#177a9a}
.venn-circle.right,.circle-b{fill:var(--right);stroke:#aa3250}
.circle-c{fill:var(--third);stroke:#c08a1d}
.circle-d{fill:var(--fourth);stroke:#469960}
.circle-label{font-size:16px;font-weight:900;fill:#24303d}
.venn-content{height:100%;display:flex;align-items:center;justify-content:center;text-align:center;padding:10px;font-size:14px;line-height:1.38;font-weight:650;color:#12202c}
.venn-content ul{padding:0;margin:0;list-style:none}
.venn-content li{margin:0 0 11px}
.overlap-content{font-size:13.5px;color:#2b1420}
.diagram-note,.interaction-hint{margin:0 20px 16px;color:var(--muted);font-size:.82rem;line-height:1.5}
.interaction-hint{text-align:center;margin-top:-4px}
.region-label{cursor:pointer}
.region-label rect{fill:rgba(255,255,255,.9);stroke:#b9c0ca;stroke-width:1.5;transition:.18s}
.region-label text{font-weight:900;font-size:13px;fill:#283442;pointer-events:none}
.region-label:hover rect,.region-label.active rect{fill:#6d0014;stroke:#6d0014;filter:drop-shadow(0 7px 8px rgba(109,0,20,.18))}
.region-label:hover text,.region-label.active text{fill:#fff}
.details-panel{padding:24px;min-height:430px}
.details-panel h3{font-family:Georgia,serif;font-size:1.45rem;margin:0 0 8px}
.region-kicker{font-size:.75rem;text-transform:uppercase;letter-spacing:.12em;color:var(--brain);font-weight:900;margin-bottom:14px}
.comparison-block{padding:16px 0;border-top:1px solid var(--line)}
.comparison-block:first-of-type{border-top:0;padding-top:0}
.comparison-block h4{font-size:.8rem;text-transform:uppercase;letter-spacing:.1em;margin:0 0 8px;color:var(--brain)}
.comparison-block p,.comparison-block li{color:#4f5a68;line-height:1.55;font-size:.92rem}
.comparison-block p{margin:0}
.comparison-block ul{margin:0;padding-left:18px}
.pdf-links{display:grid;gap:8px;margin-top:18px}
.pdf-link{display:flex;align-items:center;justify-content:space-between;text-decoration:none;color:var(--ink);padding:11px 12px;background:#f6f7f9;border-radius:10px;font-weight:700;font-size:.86rem}
.pdf-link:hover{background:#eee2e5;color:var(--brain)}
.method-section{border-top:1px solid var(--line)}
.method-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:26px}
.method-grid article{background:#fff;border:1px solid var(--line);border-radius:16px;padding:22px}
.method-grid span{font-weight:900;color:var(--brain);font-size:.8rem}
.method-grid h3{font-family:Georgia,serif;margin:12px 0 8px}
.method-grid p{margin:0;color:var(--muted);line-height:1.55}
footer{padding:28px max(4vw,24px);background:#1f242b;color:#fff;display:flex;justify-content:space-between;gap:20px;font-size:.85rem}
footer span{color:#aeb6c0}
@media(max-width:1180px){.article-grid{grid-template-columns:repeat(2,1fr)}.comparison-layout{grid-template-columns:1fr}.site-header{align-items:flex-start}}
@media(max-width:980px){.method-grid{grid-template-columns:1fr}.venn-content{font-size:12px}.overlap-content{font-size:11.5px}}
@media(max-width:640px){.site-header{padding:38px 22px;display:block}.brand-mark{width:64px;height:64px;margin-bottom:22px;transform:scale(.8);transform-origin:left top}.section-heading,.selection-row{align-items:flex-start;flex-direction:column}.diagram-wrap svg{min-width:820px}.article-grid{grid-template-columns:1fr}.article-option{min-height:auto}footer{flex-direction:column}}