:root {
  color-scheme: light;
  --accent: #1a0dab;
  --text: #000;
  --border: #e5e5e5;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: #fff;
  color: var(--text);
  font: 400 1rem/1.72 "Verdana", Helvetica, Arial, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  letter-spacing: -.008em;
  -webkit-font-smoothing: antialiased;
}
a, a:visited { color: var(--accent); text-decoration: none; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 5px; border-radius: 2px; }
.page { max-width: 1040px; margin: 0 auto; padding: 0 40px 48px; }
.topbar { min-height: 56px; display: flex; align-items: center; justify-content: flex-end; }
.language-switch { display: flex; align-items: center; gap: 9px; }
.language-switch[hidden] { display: none; }
.language-switch button { padding: 10px 3px; border: 0; background: none; font: inherit; font-size: .875rem; color: inherit; cursor: pointer; }
.language-switch button[aria-pressed="true"] { text-decoration: underline; text-underline-offset: 6px; text-decoration-thickness: 2px; }
.course-header { padding: 24px 0 28px; }
h1 { font-size: 2.125rem; line-height: 1.3; font-weight: 600; letter-spacing: -.025em; margin: 0 0 13px; overflow-wrap: anywhere; }
.institution { margin: 0; }
.introduction { margin: 18px 0 0; max-width: 920px; }
h2 { margin: 0 0 12px; font-size: 1.3rem; font-weight: 600; }
.information-section { margin-bottom: 28px; }
.lecture-list { list-style: none; padding: 0; margin: 0; }
.references-list { list-style: none; margin: 0; padding: 0; }
.references-list li + li { margin-top: 6px; }
.references-list li { overflow-wrap: anywhere; }
.references-list time { white-space: nowrap; }
table { width: 100%; border-collapse: collapse; text-align: left; font: inherit; color: var(--text); }
thead th { padding: 9px 18px; font: inherit; color: inherit; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
tbody th, tbody td { padding: 10px 18px; border-bottom: 1px solid var(--border); vertical-align: middle; }
tbody th { font-weight: 400; }
/* Separate borders keep the full-width top rule consistent across browsers. */
.information-table { table-layout: fixed; border-collapse: separate; border-spacing: 0; border-top: 1px solid var(--border); }
.information-label { width: 17%; }
.information-table th, .information-table td { vertical-align: top; overflow-wrap: anywhere; }
.materials-table thead th:first-child { width: 80%; }
.materials-table tbody td { white-space: nowrap; }
.staff-table { table-layout: fixed; }
.staff-table thead th:nth-child(1) { width: 15%; }
.staff-table thead th:nth-child(2) { width: 22%; }
.staff-table thead th:nth-child(3) { width: 38%; }
.staff-table thead th:nth-child(4) { width: 25%; }
.staff-table th, .staff-table td { overflow-wrap: anywhere; }
.mobile-label { display: none; }
.chapter-number { display: inline-block; font-variant-numeric: tabular-nums; margin-right: 19px; }
.materials-table td a + a { margin-left: 10px; }
.visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
.skip-link { position: absolute; top: -100px; left: 16px; padding: 8px 12px; background: white; z-index: 1; }
.skip-link:focus { top: 12px; }

@media (max-width: 900px) {
  .page { padding: 0 22px 32px; }
  .topbar { min-height: 50px; }
  .course-header { padding-top: 22px; padding-bottom: 24px; }
  h1 { font-size: 1.8rem; }
  .institution { font-size: .9375rem; }
  .materials-table, .materials-table tbody, .staff-table, .staff-table tbody { display: block; }
  .materials-table thead, .staff-table thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  .materials-table tbody tr { display: flex; flex-wrap: wrap; gap: 3px 28px; border-top: 1px solid var(--border); padding: 10px 0; }
  .materials-table tbody tr:last-child { border-bottom: 1px solid var(--border); }
  .materials-table tbody th { flex-basis: 100%; display: flex; align-items: baseline; }
  .materials-table tbody th, .materials-table tbody td { padding: 0; border: 0; }
  .materials-table tbody td { white-space: normal; }
  .materials-table tbody td a { display: inline-block; padding: 7px 0; }
  .staff-table tbody tr { display: grid; grid-template-columns: max-content minmax(0, 1fr); gap: 4px 16px; padding: 12px 0; border-top: 1px solid var(--border); }
  .staff-table tbody tr:last-child { border-bottom: 1px solid var(--border); }
  .staff-table tbody th, .staff-table tbody td { padding: 0; border: 0; min-width: 0; }
  .staff-email, .staff-hours { grid-column: 1 / -1; }
  .mobile-label { display: inline; }
  .information-table, .information-table tbody, .information-table tbody tr, .information-table th, .information-table td { display: block; width: auto; }
  .information-table colgroup { display: none; }
  .information-table tbody tr { padding: 12px 0; border-bottom: 1px solid var(--border); }
  .information-table th, .information-table td { padding: 0; border: 0; }
  .information-table th { margin-bottom: 6px; }
  .chapter-number { margin-right: 14px; flex-shrink: 0; }
}
@media (max-width: 360px) {
  .page { padding: 0 16px 28px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}