@charset "UTF-8";

:root {
  color-scheme: light;
  --concrete: #4b4f55;
  --cobalt: #1f4fd6;
  --ink: #272b31;
  --paper: #efefea;
  --slab: #deded9;
  --line: #777b80;
  --white: #ffffff;
  --body-font: "Segoe UI", Candara, Calibri, "Trebuchet MS", system-ui, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-padding-top: 1rem; }
body {
  margin: 0;
  background-color: var(--paper);
  color: var(--ink);
  font-family: var(--body-font);
  font-size: 18px;
  line-height: 1.55;
  -webkit-text-size-adjust: 100%;
}
button, summary { font: inherit; }
a { color: var(--cobalt); text-underline-offset: .2em; }
a, button, summary { min-height: 44px; }
a { display: inline-flex; align-items: center; }
button, summary { cursor: pointer; }
a:hover { text-decoration-thickness: 2px; }
a:focus-visible, button:focus-visible, summary:focus-visible {
  outline: 3px solid var(--cobalt);
  outline-offset: 5px;
}
::selection { background: var(--cobalt); color: var(--white); }
[hidden] { display: none !important; }
h1, h2, h3, p, dl { margin-top: 0; }
h1, h2, h3 { text-wrap: balance; }
h1 { font-size: clamp(2.4rem, 7.1vw, 5.7rem); line-height: 1.02; font-weight: 700; letter-spacing: -.045em; margin-bottom: 1.4rem; }
h2 { font-size: 1.65rem; line-height: 1.18; letter-spacing: -.025em; margin-bottom: 1.15rem; }
h3 { font-size: 1.4rem; line-height: 1.2; letter-spacing: -.02em; }
p { margin-bottom: 1rem; }
ul { padding-left: 1.3rem; }
li + li { margin-top: .6rem; }
main { max-width: 1248px; margin-inline: auto; padding: 0 20px 48px; }
.eyebrow { font-size: 16px; font-weight: 650; line-height: 1.35; margin-bottom: 1.2rem; color: var(--concrete); }
.skip-link { position: fixed; left: 16px; top: 16px; z-index: 20; background: var(--white); padding: 12px 20px; transform: translateY(-160%); }
.skip-link:focus { transform: translateY(0); }
.site-header { max-width: 1440px; margin-inline: auto; }
.utility-strip { background: var(--concrete); color: var(--white); padding: 10px 20px; font-size: 16px; display: flex; flex-wrap: wrap; align-items: center; gap: 0 18px; }
.utility-strip > span { flex: 1 1 180px; }
.utility-strip a { color: var(--white); text-decoration: none; justify-content: space-between; gap: 22px; }
.utility-strip a:focus-visible { outline-color: var(--white); }
.masthead { position: relative; display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 16px 20px; border-bottom: 2px solid var(--concrete); }
.wordmark { gap: 12px; color: var(--ink); text-decoration: none; font-size: 22px; font-weight: 700; line-height: 1.1; }
.wordmark-symbol { display: inline-block; width: 17px; height: 36px; background: var(--cobalt); box-shadow: 6px 6px 0 var(--concrete); margin-right: 5px; flex: none; }
.wordmark-detail { display: block; font-size: 16px; font-weight: 400; margin-top: 5px; color: var(--concrete); }
.site-menu { position: static; }
.site-menu summary { list-style: none; display: flex; align-items: center; gap: 9px; font-size: 16px; font-weight: 650; padding: 8px 0 8px 8px; }
.site-menu summary::-webkit-details-marker { display: none; }
.menu-symbol { font-size: 25px; font-weight: 400; }
.site-menu[open] .menu-symbol { transform: rotate(45deg); }
.menu-panel { position: absolute; top: 100%; left: 0; right: 0; z-index: 10; background: var(--paper); padding: 28px 20px; border-bottom: 6px solid var(--cobalt); box-shadow: 0 16px 0 #272b3112; display: grid; gap: 25px; }
.menu-group { min-width: 0; }
.menu-group h2 { font-size: 18px; border-top: 2px solid var(--concrete); padding-top: 16px; margin-bottom: 8px; }
.menu-group ul { list-style: none; padding: 0; margin: 0; }
.menu-group li + li { margin-top: 0; }
.menu-group a { width: 100%; font-size: 16px; padding-block: 9px; text-decoration: none; }
.menu-group a[aria-current] { font-weight: 700; text-decoration: underline; }
.home-intro, .chapter-intro { padding-top: 38px; padding-bottom: 35px; }
.intro-copy { min-width: 0; }
.intro-lede { max-width: 48ch; color: var(--concrete); font-size: 20px; line-height: 1.5; margin-bottom: 1.5rem; }
.primary-link { background: var(--cobalt); color: var(--white); padding: 15px 20px; justify-content: space-between; gap: 30px; text-decoration: none; font-weight: 650; }
.primary-link:hover { background: #163fb5; }
.primary-link:focus-visible { outline-offset: 4px; }
.breadcrumb { text-decoration: none; gap: 18px; font-size: 16px; margin-bottom: 25px; }
.abstract-block { overflow: hidden; position: relative; height: 140px; margin-top: 30px; background-color: var(--slab); background-image: radial-gradient(circle, #4b4f5526 1px, transparent 1.3px), radial-gradient(circle, #ffffff80 1px, transparent 1.4px); background-size: 6px 7px, 13px 11px; border: 2px solid var(--concrete); }
.geometry-grid { position: absolute; inset: 0; background-image: linear-gradient(#4b4f5529 1px, transparent 1px), linear-gradient(90deg, #4b4f5529 1px, transparent 1px); background-size: 48px 48px; }
.geometry-slab { position: absolute; inset: 18% 17% 18% 7%; border: 3px solid var(--concrete); background: #c7c8c3; box-shadow: 13px 13px 0 #4b4f553b; }
.geometry-orbit { position: absolute; height: 140px; width: 140px; border: 23px solid var(--paper); border-radius: 50%; right: 5%; bottom: -25px; }
.geometry-stripe { position: absolute; background: var(--cobalt); height: 220%; width: 35px; top: -70%; left: 54%; transform: rotate(25deg); }
.geometry-rule { position: absolute; background: var(--concrete); height: 6px; left: 0; right: 48%; top: 50%; }
.chapter-intro .abstract-block { height: 82px; }
.chapter-intro .geometry-orbit { height: 115px; width: 115px; border-width: 16px; }
.reading-layout { border-top: 5px solid var(--concrete); }
.chapter-body { min-width: 0; padding-block: 30px; }
.answer-section { max-width: 66ch; }
.answer-section + .answer-section { border-top: 1px solid var(--line); padding-top: 30px; margin-top: 30px; }
.answer-section p:last-child { margin-bottom: 0; }
.margin-notes { background-color: var(--slab); padding: 24px; border-left: 6px solid var(--cobalt); margin-bottom: 30px; min-width: 0; }
.margin-notes .eyebrow { color: var(--ink); }
.definition + .definition { margin-top: 24px; border-top: 1px solid var(--line); padding-top: 18px; }
.definition dt { font-size: 18px; font-weight: 700; margin-bottom: 6px; }
.definition dd { margin: 0; font-size: 16px; line-height: 1.55; color: var(--concrete); }
.margin-link { margin-top: 25px; font-size: 16px; gap: 12px; align-items: center; width: 100%; }
.question-hub { border-top: 5px solid var(--concrete); padding-top: 10px; }
.question-chapter { padding-block: 27px; border-bottom: 2px solid var(--concrete); }
.question-chapter-heading { display: flex; align-items: flex-start; gap: 14px; margin-bottom: 22px; }
.question-chapter-heading h2 { margin-bottom: 0; }
.chapter-mark { display: inline-block; flex: none; width: 19px; height: 19px; background: var(--cobalt); margin-top: 5px; }
.question-cards { display: grid; }
.question-card { min-width: 0; display: flex; align-items: center; gap: 16px; padding: 23px 20px; border: 1px solid var(--line); margin-top: -1px; color: var(--ink); text-decoration: none; background: #ffffff26; }
.question-card:hover, .question-card:focus-visible { background: var(--white); }
.question-card-copy { display: flex; flex: 1; flex-direction: column; gap: 8px; min-width: 0; }
.question-card-title { font-size: 21px; font-weight: 650; line-height: 1.2; }
.question-card-detail { font-size: 16px; color: var(--concrete); line-height: 1.5; max-width: 50ch; }
.question-arrow { color: var(--cobalt); font-size: 28px; align-self: flex-start; line-height: 1; flex: none; }
.question-list { margin-block: 0; }
.question-list li { padding-left: 6px; margin-bottom: 14px; }
.evidence-notes { border-top: 5px solid var(--concrete); padding-top: 30px; margin-top: 20px; }
.evidence-notes h2 { margin-bottom: 16px; }
.evidence-notes ul { list-style: none; padding: 0; margin: 0 0 20px; max-width: 66ch; }
.evidence-notes li + li { margin-top: 0; }
.evidence-notes li { border-bottom: 1px solid #4b4f5538; }
.evidence-notes a { font-size: 16px; justify-content: space-between; gap: 24px; width: 100%; padding: 13px 0; }
.evidence-notes a span { flex: none; }
.source-date { font-size: 16px; color: var(--concrete); margin-bottom: 5px; }
.next-note { margin-top: 35px; padding: 25px 20px; color: var(--white); background: var(--cobalt); }
.next-note .eyebrow { color: var(--white); margin-bottom: 10px; display: block; }
.next-note a { color: var(--white); font-size: 24px; line-height: 1.3; font-weight: 650; justify-content: space-between; gap: 24px; text-decoration: none; width: 100%; }
.next-note a:focus-visible { outline-color: var(--white); }
.site-footer { color: var(--white); background-color: var(--concrete); padding: 32px 20px; }
.footer-top, .footer-line, .footer-domain { max-width: 1208px; margin-inline: auto; }
.footer-mark { font-size: 28px; letter-spacing: -.025em; font-weight: 650; line-height: 1.1; max-width: 16ch; margin-bottom: 20px; }
.footer-top nav { display: grid; gap: 0; margin-bottom: 28px; }
.footer-top a { width: fit-content; color: var(--white); font-size: 16px; padding-block: 10px; }
.footer-line { font-size: 16px; line-height: 1.6; padding-top: 24px; border-top: 1px solid #ffffff69; }
.footer-domain { font-size: 16px; margin-bottom: 0; color: var(--white); overflow-wrap: anywhere; }
.footer-top a:focus-visible { outline-color: var(--white); }
.comparison { margin-bottom: 36px; }
.comparison-controls { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 20px; }
.comparison-controls button { padding: 10px 13px; font-size: 16px; border: 2px solid var(--concrete); color: var(--ink); background: var(--paper); }
.comparison-controls button[aria-pressed="true"] { border-color: var(--cobalt); background: var(--cobalt); color: var(--white); }
.comparison-panels { display: grid; gap: 16px; }
.comparison-panel { border: 2px solid var(--concrete); background: var(--slab); min-width: 0; }
.comparison-panel h3 { padding: 18px; margin: 0; color: var(--white); background: var(--concrete); }
.comparison-panel dl { padding: 18px; margin: 0; }
.comparison-panel dl > div + div { margin-top: 22px; }
.comparison-panel dt { font-weight: 650; font-size: 18px; margin-bottom: 6px; }
.comparison-panel dd { margin: 0; font-size: 16px; line-height: 1.55; }
.comparison-status { margin-block: 15px 0; font-size: 16px; color: var(--concrete); }
.missing-links { border-top: 5px solid var(--concrete); padding-top: 30px; display: grid; gap: 10px; }
.missing-links a { width: fit-content; padding-block: 10px; }

@media (min-width: 640px) {
  main { padding-inline: 32px; }
  .utility-strip, .masthead { padding-inline: 32px; }
  .utility-strip { padding-block: 0; }
  .menu-panel { grid-template-columns: repeat(2, minmax(0, 1fr)); padding-inline: 32px; }
  .home-intro { display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr); gap: 36px; align-items: stretch; }
  .home-intro .abstract-block { height: auto; margin-top: 0; }
  .home-intro .geometry-slab { inset: 13% 17% 14% 10%; }
  .home-intro .geometry-orbit { width: 220px; height: 220px; bottom: -45px; right: -65px; border-width: 33px; }
  .home-intro .geometry-stripe { width: 52px; }
  .question-cards { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .question-card { margin-right: -1px; }
  .comparison-panels { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .comparison-panels[data-view="remote"], .comparison-panels[data-view="room"] { grid-template-columns: 1fr; }
  .footer-top { display: flex; gap: 40px; justify-content: space-between; }
  .footer-top nav { grid-template-columns: repeat(3, auto); gap: 25px; }
  .site-footer { padding-inline: 32px; }
}

@media (min-width: 980px) {
  .masthead { padding-inline: max(48px, calc((100% - 1208px) / 2)); padding-block: 22px; }
  .utility-strip { padding-inline: max(48px, calc((100% - 1208px) / 2)); }
  .wordmark { font-size: 26px; }
  .site-menu summary { font-size: 18px; min-width: 172px; justify-content: space-between; }
  .menu-panel { grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 32px; padding: 38px max(48px, calc((100% - 1208px) / 2)); }
  .home-intro { padding-block: 65px 55px; grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr); gap: 60px; }
  .home-intro h1 { font-size: 86px; }
  .home-intro .intro-copy { padding-bottom: 12px; }
  .home-intro .intro-lede { font-size: 22px; max-width: 42ch; }
  .home-intro .abstract-block { min-height: 465px; }
  .home-intro .geometry-slab { inset: 12% 15% 13% 12%; border-width: 5px; box-shadow: 20px 20px 0 #4b4f553b; }
  .home-intro .geometry-orbit { width: 270px; height: 270px; border-width: 42px; }
  .home-intro .geometry-stripe { width: 72px; left: 47%; }
  .home-intro .geometry-rule { height: 10px; }
  .chapter-intro { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 1fr); gap: 60px; padding-block: 48px; align-items: end; }
  .chapter-intro h1 { font-size: 62px; max-width: 20ch; }
  .chapter-intro .abstract-block { height: 170px; margin-bottom: 8px; }
  .chapter-intro .geometry-orbit { height: 145px; width: 145px; border-width: 22px; right: -50px; }
  .chapter-intro .intro-lede { max-width: 62ch; }
  .reading-layout { display: grid; grid-template-columns: minmax(0, 1fr) 260px; gap: 72px; align-items: start; }
  .chapter-body { padding-block: 38px; }
  .answer-section { max-width: 65ch; }
  .answer-section h2 { font-size: 30px; }
  .margin-notes { margin-top: 38px; padding: 25px; }
  .question-chapter { display: grid; grid-template-columns: 260px minmax(0, 1fr); gap: 58px; padding-block: 36px; }
  .question-chapter-heading h2 { font-size: 27px; max-width: 14ch; }
  .question-card { padding: 27px 23px; min-height: 143px; }
  .question-card-title { font-size: 23px; }
  .evidence-notes { display: grid; grid-template-columns: 260px minmax(0, 1fr); column-gap: 58px; padding-top: 36px; }
  .evidence-notes > .eyebrow { grid-column: 1; margin-bottom: 8px; }
  .evidence-notes > h2 { grid-column: 1; font-size: 30px; }
  .evidence-notes ul { grid-column: 2; grid-row: 1 / span 5; width: 100%; }
  .evidence-notes .source-date { grid-column: 1; max-width: 23ch; }
  .next-note { margin-top: 40px; padding: 30px; }
  .next-note a { font-size: 30px; }
  .site-footer { padding-block: 48px; }
  .footer-mark { font-size: 35px; }
  .footer-top nav { gap: 45px; }
  .footer-line { max-width: 1208px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

@media print {
  body { background: white; font-size: 16px; }
  .utility-strip, .site-menu, .abstract-block, .comparison-controls, .comparison-status, .skip-link, .primary-link, .next-note, .margin-link, .site-footer { display: none; }
  main { max-width: none; padding: 0; }
  .masthead { border-bottom: 2px solid var(--concrete); padding: 0 0 16px; }
  .chapter-intro, .home-intro, .reading-layout, .evidence-notes { display: block; }
  h1, .chapter-intro h1, .home-intro h1 { font-size: 36px; }
  .margin-notes { border: 1px solid var(--concrete); }
  .comparison-panel[hidden] { display: block !important; }
  .answer-section, .evidence-notes, .comparison-panel { break-inside: avoid; }
  a { color: var(--ink); }
}