:root {
  color-scheme: light;
  --paper: #f5f2e9;
  --ink: #282b25;
  --muted: #65675e;
  --accent: #85362f;
  --line: #d6d5c9;
  --serif: Georgia, "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 28px; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: var(--sans); font-size: 15px; line-height: 1.6; -webkit-font-smoothing: antialiased; }
::selection { background: #e4c7b7; color: var(--ink); }
a { color: inherit; text-underline-offset: 4px; }
a:hover { color: var(--accent); }
a:focus-visible { outline: 3px solid var(--accent); outline-offset: 6px; border-radius: 2px; }
h1, h2, h3, h4, p, figure { margin: 0; }
.page { max-width: 1280px; padding: 0 56px; margin: 0 auto; }
.skip-link { position: absolute; top: -80px; left: 16px; background: var(--ink); color: white; padding: 10px 18px; z-index: 2; }
.skip-link:focus { top: 12px; }
.masthead { min-height: 100px; display: flex; align-items: center; justify-content: space-between; gap: 24px; border-bottom: 1px solid var(--line); }
.masthead a { text-decoration: none; }
.wordmark { font-size: 14px; font-weight: 600; display: flex; align-items: center; gap: 12px; letter-spacing: -.2px; }
.wordmark-symbol { font: 33px/1 var(--serif); color: var(--accent); }
.masthead nav { display: flex; gap: 30px; margin-left: auto; margin-right: 44px; font-size: 13px; }
.back-link { font: 11px var(--mono); text-transform: uppercase; letter-spacing: 1px; }
.back-link span { margin-left: 6px; }
.hero { padding: 76px 0 68px; display: grid; grid-template-columns: 1.12fr 1fr; align-items: center; gap: 64px; }
.eyebrow { font: 10px/1.6 var(--mono); text-transform: uppercase; letter-spacing: 1.6px; color: var(--accent); display: flex; align-items: center; gap: 10px; }
.small-rule { height: 1px; width: 24px; background: var(--accent); }
h1 { font: 108px/.95 var(--serif); letter-spacing: -6px; margin: 24px 0 24px; font-weight: 400; }
h1 em { color: var(--accent); font-weight: 400; }
.lede { font: 25px/1.35 var(--serif); letter-spacing: -.4px; }
.hero-description { margin-top: 17px; color: var(--muted); font-size: 14px; max-width: 395px; line-height: 1.8; }
.hero-actions { display: flex; align-items: center; gap: 22px; margin-top: 30px; flex-wrap: wrap; }
.button { display: inline-flex; justify-content: space-between; align-items: center; gap: 24px; padding: 13px 17px; font-size: 12px; font-weight: 500; text-decoration: none; }
.button-primary { background: var(--accent); color: #fffaf2; border: 1px solid var(--accent); }
.button-primary:hover { background: #6b2b26; color: white; }
.text-link { font-size: 12px; text-decoration-color: #aaa99d; }
.text-link span { margin-left: 6px; }
.notation-plate { align-self: center; border: 1px solid #cecec0; background-color: #efeee4; background-image: linear-gradient(#deded345 1px, transparent 1px), linear-gradient(90deg, #deded345 1px, transparent 1px); background-size: 24px 24px; padding: 22px 28px 19px; transform: rotate(-1.4deg); box-shadow: 7px 9px 0 #e7e5d9; }
.plate-heading { display: flex; justify-content: space-between; align-items: center; gap: 16px; font: 9px/1.4 var(--mono); text-transform: uppercase; letter-spacing: .7px; color: var(--muted); border-bottom: 1px solid #cdcec0; padding-bottom: 16px; }
.plate-heading span:last-child { white-space: nowrap; }
.math-expression { display: flex; justify-content: center; align-items: center; gap: 12px; margin: 31px 0 25px; font: italic 32px var(--serif); white-space: nowrap; }
.sum { display: flex; flex-direction: column; align-items: center; font: 12px/1.2 var(--serif); }
.sum b { font: 64px/.95 var(--serif); }
sup { font-size: .6em; }
.plate-code { display: flex; flex-direction: column; gap: 8px; padding: 15px 0 18px; border-bottom: 1px solid #cdcec0; }
.code-label { font: 9px var(--mono); text-transform: uppercase; letter-spacing: 1px; color: var(--muted); }
.plate-code code { font: 13px/1.5 var(--mono); color: var(--accent); white-space: nowrap; }
.visual-proof { display: flex; align-items: center; justify-content: center; gap: 25px; padding: 26px 0; }
.square-grid { display: grid; width: 135px; aspect-ratio: 1; grid-template-columns: repeat(5, 1fr); gap: 3px; }
.square-grid i { aspect-ratio: 1; border-radius: 1px; }
.layer-1 { background: #85362f; }.layer-2 { background: #a75a48; }.layer-3 { background: #bd8263; }.layer-4 { background: #d1a67d; }.layer-5 { background: #dfc69a; }
.proof-caption { display: flex; flex-direction: column; gap: 7px; font: 16px var(--serif); }
.proof-result { color: var(--accent); font-size: 37px; }
.notation-plate figcaption { font: 10px/1.7 var(--sans); color: var(--muted); border-top: 1px solid #cdcec0; padding-top: 13px; }
.course-note { display: flex; gap: 22px; background: #ebece3; border-left: 2px solid #828b71; padding: 26px 30px; margin-bottom: 68px; }
.note-mark { font: 30px/1.2 var(--serif); color: #5b6955; }
.course-note h2 { font-size: 14px; font-weight: 600; margin-bottom: 7px; }
.course-note p { font-size: 12px; line-height: 1.85; color: #555d4e; max-width: 940px; }
.course-note a { text-decoration-color: #a8afa0; }
.resource-section { margin-bottom: 62px; }
.section-heading { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; margin-bottom: 25px; padding-top: 20px; border-top: 1px solid var(--ink); }
.section-heading > div { display: flex; align-items: baseline; gap: 17px; }
.section-number { font: 11px var(--mono); color: var(--accent); }
.section-heading h2 { font: 29px/1.3 var(--serif); letter-spacing: -.6px; }
.section-heading > p { color: var(--muted); font-size: 11px; }
.lecture-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.resource-card { border: 1px solid var(--line); padding: 24px 27px; display: flex; flex-direction: column; text-decoration: none; min-height: 283px; transition: border-color .18s, background-color .18s; }
.resource-card:hover { border-color: var(--accent); color: var(--ink); background: #ede8db; }
.featured-card { background: #eee8dc; border-color: #cabca8; }
.card-top { display: flex; align-items: center; justify-content: space-between; margin-bottom: 23px; min-height: 23px; }
.pill { font: 9px var(--mono); text-transform: uppercase; letter-spacing: 1px; background: var(--accent); color: #fffaf2; padding: 5px 8px; }
.format-label { font: 9px var(--mono); text-transform: uppercase; letter-spacing: 1px; color: var(--muted); }
.card-arrow { font-size: 20px; line-height: 1; color: var(--accent); }
.resource-meta { color: var(--muted); font: 9px/1.7 var(--mono); text-transform: uppercase; letter-spacing: .6px; }
.resource-card h3 { font: 30px/1.3 var(--serif); letter-spacing: -.6px; margin: 6px 0 10px; }
.title-year { color: #8b8b7f; font-style: italic; font-size: 23px; }
.card-description { font-size: 12px; line-height: 1.8; color: var(--muted); max-width: 390px; margin-bottom: 22px; }
.card-action { margin-top: auto; font-size: 11px; color: var(--accent); }
.card-action span { margin-left: 8px; }
.section-footnote { font-size: 11px; color: var(--muted); margin-top: 17px; line-height: 1.8; }
.section-footnote a { text-decoration-color: var(--line); }
.course-row { display: grid; grid-template-columns: 225px 1fr; padding: 28px 0 31px; border-bottom: 1px solid var(--line); gap: 32px; }
.course-row:first-of-type { padding-top: 10px; }
.course-id { display: flex; flex-direction: column; gap: 4px; }
.course-id > span { font: 10px/1.8 var(--mono); color: var(--muted); }
.course-id > span:first-child { text-transform: uppercase; letter-spacing: 1px; }
.course-id h3 { font: 35px/1.3 var(--serif); letter-spacing: -1px; }
.course-details h4 { font: 24px/1.35 var(--serif); letter-spacing: -.25px; margin-bottom: 12px; }
.course-details > p { font-size: 12px; color: var(--muted); line-height: 1.9; max-width: 650px; }
.link-group { display: flex; flex-wrap: wrap; gap: 11px 23px; margin-top: 18px; }
.link-group a { font-size: 11px; text-decoration-color: var(--line); }
.link-group a > span:last-child { color: var(--accent); margin-left: 4px; }
.inline-format { font: 8px var(--mono); color: var(--muted); }
.course-details .availability-note { font-size: 10px; font-style: italic; margin-top: 17px; }
.readings-section .section-heading { margin-bottom: 8px; }
.reading-row { display: grid; grid-template-columns: 45px 1fr auto; gap: 18px; padding: 25px 0; text-decoration: none; border-bottom: 1px solid var(--line); }
.reading-number { font: italic 27px var(--serif); color: var(--accent); padding-top: 13px; }
.reading-row h3 { font: 25px/1.4 var(--serif); letter-spacing: -.4px; margin: 4px 0 7px; }
.reading-row div > p:last-child { color: var(--muted); font-size: 12px; max-width: 650px; }
.reading-source { font: 10px var(--mono); color: var(--muted); align-self: center; white-space: nowrap; }
.reading-source span { font-size: 16px; color: var(--accent); margin-left: 14px; }
.reading-route { padding: 32px 38px 35px; background: #eae5da; margin-bottom: 58px; }
.reading-route h2 { font: 32px/1.4 var(--serif); margin: 9px 0; }
.reading-route > p:last-child { font-size: 13px; max-width: 780px; color: #5e5d53; line-height: 1.9; }
.reading-route a { text-decoration-color: #aaa99d; }
.site-footer { padding: 25px 0 32px; border-top: 1px solid var(--line); display: flex; justify-content: space-between; gap: 16px; color: var(--muted); font-size: 10px; }
.site-footer > p:first-child > span:first-child { font: 18px var(--serif); color: var(--accent); vertical-align: middle; margin-right: 8px; }
.footer-divider { color: #aaa99d; margin: 0 7px; }
.site-footer a { text-decoration: none; }

@media (min-width: 1400px) {
  .hero { gap: 90px; }
}
@media (max-width: 1000px) {
  .page { padding: 0 36px; }
  .hero { gap: 35px; padding: 62px 0; }
  h1 { font-size: 88px; letter-spacing: -4px; }
  .lede { font-size: 23px; }
  .notation-plate { padding: 20px; }
  .math-expression { font-size: 26px; gap: 8px; }
  .sum b { font-size: 53px; }
  .plate-code code { font-size: 11px; }
  .visual-proof { gap: 19px; }
  .square-grid { width: 115px; }
  .proof-caption { font-size: 13px; }
  .course-row { grid-template-columns: 175px 1fr; }
  .hero-actions { gap: 17px; }
}
@media (max-width: 760px) {
  .page { padding: 0 24px; }
  .masthead { flex-wrap: wrap; padding: 20px 0 14px; gap: 17px; }
  .wordmark { font-size: 13px; }
  .back-link { margin-left: auto; }
  .masthead nav { order: 3; width: 100%; margin: 0; justify-content: flex-start; gap: 26px; font-size: 12px; }
  .hero { grid-template-columns: 1fr; gap: 40px; padding: 45px 0 43px; }
  h1 { font-size: clamp(78px, 16vw, 106px); }
  .hero-description { max-width: 470px; }
  .notation-plate { width: 100%; max-width: 465px; justify-self: center; padding: 22px 25px 18px; }
  .plate-heading { font-size: 9px; }
  .math-expression { font-size: 31px; margin-top: 23px; }
  .sum b { font-size: 60px; }
  .plate-code code { font-size: 13px; }
  .visual-proof { gap: 28px; padding: 23px 0; }
  .square-grid { width: 130px; }
  .proof-caption { font-size: 15px; }
  .course-note { padding: 22px 20px; gap: 13px; margin-bottom: 43px; }
  .course-note p { font-size: 12px; }
  .section-heading { align-items: flex-start; flex-direction: column; gap: 7px; }
  .section-heading > p { margin-left: 32px; }
  .section-heading h2 { font-size: 27px; }
  .section-heading > div { gap: 16px; }
  .lecture-grid { gap: 13px; }
  .resource-card { padding: 20px; min-height: 300px; }
  .resource-card h3 { font-size: 26px; }
  .title-year { font-size: 19px; }
  .resource-meta { font-size: 8px; }
  .course-row { grid-template-columns: 1fr; gap: 17px; }
  .course-id h3 { font-size: 31px; }
  .course-details h4 { font-size: 23px; }
  .resource-section { margin-bottom: 43px; }
  .reading-row { grid-template-columns: 26px 1fr; gap: 12px; padding: 23px 0; }
  .reading-row h3 { font-size: 23px; }
  .reading-source { grid-column: 2; }
  .reading-number { font-size: 23px; }
  .reading-route { padding: 25px; margin-bottom: 35px; }
  .site-footer { flex-direction: column; gap: 10px; }
}
@media (max-width: 480px) {
  .lecture-grid { grid-template-columns: 1fr; }
  .resource-card { min-height: 265px; }
  .resource-meta { font-size: 9px; }
  .resource-card h3 { font-size: 30px; }
  .notation-plate { padding: 18px; }
  .plate-heading { font-size: 8px; letter-spacing: .2px; gap: 8px; }
  .math-expression { font-size: 27px; gap: 6px; }
  .plate-code code { font-size: 11px; }
  .square-grid { width: 110px; }
  .visual-proof { gap: 19px; }
  .proof-caption { font-size: 13px; }
  .desktop-break { display: none; }
  .course-note { padding: 20px 16px; }
  .note-mark { font-size: 24px; }
  .reading-route h2 { font-size: 29px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .resource-card { transition: none; }
}