:root {
  --bg: #FAFAF8;
  --paper: #fff;
  --ink: #0D2540;
  --body: #526579;
  --line: #D6DFE6;
  --soft: #EAF0F4;
  --gold: #D5A44E;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
  --edge: 48px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 104px; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.65 var(--sans); -webkit-font-smoothing: antialiased; }
h1, h2, h3, p { margin: 0; }
h1, h2, h3 { font-weight: 500; }
a { color: inherit; text-underline-offset: 4px; touch-action: manipulation; }
a:hover { text-decoration-thickness: 2px; }
a:focus-visible, summary:focus-visible, [tabindex]:focus-visible { outline: 2px solid #536E85; outline-offset: 5px; }
::selection { background: var(--gold); color: var(--ink); }
strong { font-weight: 600; }
.container { width: min(100%, 1280px); padding-inline: var(--edge); margin-inline: auto; }
.skip-link { position: fixed; top: -100px; left: 20px; z-index: 30; padding: 12px 20px; color: #fff; background: var(--ink); }
.skip-link:focus { top: 12px; }
.header-nav { display: flex; align-items: center; gap: 28px; color: var(--body); font-size: 13px; }
.header-nav a { text-decoration: none; }
.header-nav a:hover { text-decoration: underline; }
.brief-hero { padding-block: 72px 52px; }
.eyebrow { color: var(--body); font: 10px/1.6 var(--mono); letter-spacing: .1em; text-transform: uppercase; }
.brief-hero .eyebrow::before { content: ""; display: inline-block; width: 26px; height: 1px; margin-right: 12px; vertical-align: middle; background: #B88736; }
h1 { max-width: 1000px; margin-top: 24px; font-size: clamp(36px, 4.3vw, 55px); line-height: 1.14; letter-spacing: -.04em; }
.lede { max-width: 850px; margin-top: 28px; color: var(--ink); font-size: 19px; line-height: 1.65; }
.study-relationship { max-width:850px; margin-top:24px; color:var(--body); font-size:15px; }
.study-relationship strong { color:var(--ink); }
.disclosure { max-width: 850px; margin-top: 28px; padding-left: 18px; border-left: 3px solid var(--gold); color: var(--body); font-size: 13px; line-height: 1.75; }
.brief-nav { display: flex; flex-wrap: wrap; gap: 12px 26px; margin-top: 28px; font-size: 13px; }
.brief-nav a { padding-block: 6px; }
.impact-section { padding-bottom: 64px; }
.impact-panel { padding: 32px 36px; border: 1px solid #28435D; border-radius: 12px; background: linear-gradient(145deg,#132F49,var(--ink) 70%); color: var(--bg); }
.impact-panel .eyebrow { color: var(--gold); }
.impact-panel h2 { margin-top: 12px; font-size: 27px; line-height: 1.25; letter-spacing: -.025em; }
.metrics { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 28px; margin-top: 28px; }
.metrics div { padding-top: 22px; border-top: 1px solid #425F78; }
.metrics strong { display: block; font-size: clamp(28px,3vw,40px); line-height: 1.2; font-weight: 450; letter-spacing: -.03em; font-variant-numeric: tabular-nums; }
.metrics span { display: block; max-width: 240px; margin-top: 12px; color: #BBCDDB; font-size: 14px; }
.impact-context { max-width: 850px; margin-top: 28px; }
.prose p { color: var(--body); }
.prose p + p { margin-top: 20px; }
.prose strong { color: var(--ink); }
.brief-section { display: grid; grid-template-columns: minmax(0,.75fr) minmax(0,2fr); gap: 64px; padding-block: 56px; border-top: 1px solid var(--line); }
.section-head h2 { margin-top: 14px; font-size: clamp(27px,2.5vw,34px); line-height: 1.18; letter-spacing: -.035em; }
.section-content { min-width: 0; }
.solver-constraints { margin-block: 20px; padding-left: 22px; color: var(--body); }
.solver-constraints li + li { margin-top: 8px; }
.table-scroll { max-width: 100%; overflow-x: auto; overscroll-behavior-x: contain; margin-block: 26px; border: 1px solid var(--line); border-radius: 10px; background: var(--paper); }
.table-scroll:first-child { margin-top: 0; }
table { width: 100%; border-collapse: collapse; font-size: 13px; line-height: 1.6; }
th, td { padding: 16px; text-align: left; vertical-align: top; border-bottom: 1px solid var(--line); }
thead th { background: var(--soft); font-weight: 550; }
td:first-child { font-weight: 550; }
tr:last-child td { border-bottom: 0; }
th[align=right], td[align=right] { text-align: right; font-variant-numeric: tabular-nums; }
.comparison-table { min-width: 580px; }
.cases-table { min-width: 720px; }
.held-out-table { min-width: 580px; }
.controls-table td:first-child { width: 31%; }
details { margin-top: 28px; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
summary { position: relative; padding: 20px 32px 20px 0; list-style: none; cursor: pointer; font-size: 15px; font-weight: 550; line-height: 1.5; touch-action: manipulation; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; position: absolute; right: 2px; top: 18px; color: var(--body); font: 22px var(--mono); }
details[open] > summary::after { content: "−"; }
.details-body { padding-bottom: 24px; }
.details-body p { font-size: 14px; }
.details-body .table-scroll { margin-top: 0; }
.evidence-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 18px 24px; margin-block: 26px; font-size: 13px; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 18px; min-height: 48px; padding: 12px 22px; border: 1px solid var(--ink); border-radius: 100px; background: var(--ink); color: #fff; font-size: 14px; font-weight: 550; line-height: 1.4; text-decoration: none; }
.button:hover { background: #1D3D5B; text-decoration: none; }
.notes-link { margin-top: 20px; font-size: 14px; }
.closing { padding-block: 60px; background: #F5EBD8; border-top: 1px solid var(--line); }
.closing-inner { display: grid; grid-template-columns: minmax(0,1.5fr) minmax(0,1fr); align-items: center; gap: 64px; }
.closing h2 { margin-top: 16px; max-width: 600px; font-size: clamp(30px,3vw,40px); letter-spacing: -.035em; line-height: 1.18; }
.closing p + p { margin-top: 24px; }
.closing .prose { max-width: 600px; }
.technical-intro { max-width: 780px; }

@media(max-width:1000px) {
  .brief-section { grid-template-columns: minmax(0,.8fr) minmax(0,2fr); gap: 32px; }
  .closing-inner { gap: 32px; }
  .metrics { gap: 20px; }
  .metrics strong { font-size: 30px; }
}
@media(max-width:800px) {
  :root { --edge: 28px; }
  .brief-hero { padding-block: 48px 36px; }
  .brief-section { grid-template-columns: minmax(0,1fr); gap: 26px; padding-block: 40px; }
  .section-head h2 { max-width: 620px; }
  .impact-panel { padding: 28px; }
  .metrics { grid-template-columns: minmax(0,1fr); gap: 20px; }
  .metrics div { display: grid; grid-template-columns: minmax(0,1fr) minmax(0,1.25fr); align-items: start; gap: 20px; padding-top: 20px; }
  .metrics span { margin-top: 0; }
  .metrics strong { font-size: 32px; }
  .closing-inner { grid-template-columns: minmax(0,1fr); gap: 26px; }
}
@media(max-width:560px) {
  :root { --edge: 20px; }
  .header-nav { gap: 12px; font-size: 12px; }
  .header-evidence { display: none; }
  .brief-hero .eyebrow { font-size: 9px; letter-spacing: .06em; }
  .brief-hero .eyebrow::before { width: 18px; margin-right: 8px; }
  h1 { margin-top: 20px; font-size: clamp(34px,8.4vw,44px); }
  .lede { font-size: 17px; margin-top: 24px; }
  .impact-section { padding-bottom: 40px; }
  .impact-panel { padding: 24px 20px; }
  .impact-panel h2 { font-size: 24px; }
  .metrics div { grid-template-columns: minmax(0,1fr); gap: 8px; }
  .metrics span { max-width: none; }
  .metrics strong { font-size: 34px; }
  th, td { padding: 14px 12px; }
  .controls-table td:first-child { width: 36%; }
  .evidence-actions { align-items: flex-start; flex-direction: column; }
  .button { max-width: 100%; padding-inline: 18px; font-size: 13px; }
  .closing { padding-block: 44px; }
}
@media(prefers-reduced-motion:reduce) { html { scroll-behavior: auto; } }
@media print {
  .site-header, .brief-nav, .closing, .site-footer, .skip-link { display: none; }
  body { background: #fff; }
  .container { width: 100%; padding: 0; }
  .brief-section { display: block; padding-block: 24px; }
  .section-head { margin-bottom: 18px; }
  .table-scroll { overflow: visible; }
  table { min-width: 0 !important; }
  .impact-panel { background: #fff; color: var(--ink); }
  .metrics span, .impact-panel .eyebrow { color: var(--body); }
}