:root {
  --page-bg: #eef2f7;
  --surface: #ffffff;
  --surface-strong: #e5edf6;
  --border: #c8d3df;
  --text: #18212f;
  --muted: #556273;
  --link: #1f4f8a;
  --link-visited: #5a4f82;
  --link-hover: #8b2f3b;
  --heading: #234567;
  --accent: #183552;
  --sidebar-width: 19rem;
  --content-width: 60rem;
  --shadow: 0 12px 28px rgba(24, 42, 66, 0.1);
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
}

body {
  margin: 0;
  background: linear-gradient(180deg, #f7f9fc 0%, var(--page-bg) 20rem, #f3f6fa 100%);
  color: var(--text);
  font-family: Georgia, "Times New Roman", serif;
  line-height: 1.65;
}

a {
  color: var(--link);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.14em;
}

a:visited {
  color: var(--link-visited);
}

a:hover,
a:focus,
a:active {
  color: var(--link-hover);
}

:focus-visible {
  outline: 3px solid var(--link-hover);
  outline-offset: 3px;
}

main:focus {
  outline: none;
}

img {
  max-width: 100%;
  height: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th,
td {
  padding: 0.65rem 0.75rem;
  border-top: 1px solid var(--border);
  vertical-align: top;
  text-align: left;
}

th {
  background: var(--surface-strong);
}

caption {
  padding: 0 0 0.65rem;
  text-align: left;
  font-weight: 700;
}

dl {
  display: grid;
  grid-template-columns: minmax(8rem, 12rem) 1fr;
  gap: 0.35rem 1rem;
}

dt {
  font-weight: 700;
}

dd {
  margin: 0;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -4rem;
  background: #fff;
  color: var(--text);
  padding: 0.65rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: 0.3rem;
  z-index: 1000;
}

.skip-link:focus {
  top: 1rem;
}

.site-shell {
  display: grid;
  grid-template-columns: minmax(16rem, var(--sidebar-width)) minmax(0, 1fr);
  min-height: 100vh;
}

.site-sidebar {
  border-right: 1px solid var(--border);
  background: linear-gradient(180deg, #dde7f1 0%, #eef3f8 100%);
  padding: 1.5rem 1.25rem 2rem;
}

.sidebar-inner {
  position: sticky;
  top: 0;
  max-height: 100vh;
  overflow-y: auto;
  padding-right: 0.25rem;
  font-family: Arial, Helvetica, sans-serif;
  color: #243245;
}

.sidebar-inner h2,
.sidebar-inner h3 {
  color: var(--heading);
  margin: 1.15rem 0 0.45rem;
  line-height: 1.25;
}

.sidebar-inner h2 {
  font-size: 1.05rem;
}

.sidebar-inner h3 {
  font-size: 0.95rem;
}

.sidebar-inner ul {
  margin: 0.2rem 0 0.8rem 1.1rem;
  padding: 0;
}

.sidebar-inner li {
  margin: 0 0 0.35rem;
}

.sidebar-photo-link {
  display: inline-block;
}

.sidebar-photo {
  display: block;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.sidebar-home {
  margin: 1rem 0 0.7rem;
  font-size: 1.05rem;
}

.sidebar-home strong {
  color: var(--heading);
}

.site-main {
  padding: 2rem clamp(1.2rem, 3vw, 2.75rem) 3rem;
}

.site-main > * {
  max-width: var(--content-width);
}

.site-main > header:first-child {
  margin-bottom: 1.5rem;
}

.site-main > .container {
  max-width: var(--content-width);
  margin: 0;
  padding: 0;
}

.site-main h1,
.site-main h2,
.site-main h3,
.site-main h4 {
  color: var(--accent);
  line-height: 1.25;
}

.site-main h1 {
  margin-top: 0;
  font-size: clamp(1.8rem, 3vw, 2.5rem);
}

.site-main h2 {
  margin-top: 1.75rem;
  font-size: 1.4rem;
}

.site-main h3 {
  margin-top: 1.35rem;
  font-size: 1.15rem;
}

.site-main p,
.site-main ul,
.site-main ol,
.site-main table,
.site-main dl,
.site-main blockquote,
.site-main .course-header,
.site-main .note {
  max-width: var(--content-width);
}

.site-main hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 1.5rem 0;
}

.site-main .lead {
  color: var(--muted);
  font-style: italic;
}

.site-main .lead,
.site-main .note {
  font-size: 1.03rem;
}

.site-main .table-wrap,
.site-main .table-responsive {
  overflow-x: auto;
}

.site-main .panel {
  margin: 1rem 0;
  border: 1px solid var(--border);
  background: var(--surface);
}

.site-main .panel-heading,
.site-main .panel-body {
  padding: 0.9rem 1rem;
}

.site-main .panel-heading {
  background: var(--surface-strong);
}

.site-main .panel-title {
  margin: 0;
}

.site-main .abstract {
  margin-top: 0.65rem;
  padding-left: 0.75rem;
  border-left: 2px solid var(--border);
}

.site-main .visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.site-main .contact-section,
.site-main .layout,
.site-main footer,
.site-main header {
  max-width: var(--content-width);
}

.site-main .layout {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(15rem, 1fr);
  gap: 2rem;
  align-items: start;
}

.site-main .side-image {
  justify-self: end;
}

.site-main .talks li,
.site-main li {
  margin-bottom: 0.5rem;
}

.site-main .course-header {
  margin-bottom: 1.5rem;
  padding: 1rem 1.2rem;
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.site-main .course-header h1 {
  margin-bottom: 0.35rem;
}

.site-main .course-term {
  margin: 0 0 1rem;
  color: var(--muted);
  font-size: 1.08rem;
  font-style: italic;
}

.site-main .course-meta {
  margin: 0;
}

.site-main .course-meta dt {
  color: var(--heading);
}

.site-main .legacy-list,
.site-main .icon-link-list {
  padding-left: 1.35rem;
}

.site-main .icon-link-list {
  list-style: none;
  padding-left: 0;
}

.site-main .icon-link-list li {
  display: flex;
  gap: 0.85rem;
  align-items: flex-start;
  margin-bottom: 1rem;
}

.site-main .icon-link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
}

.site-main .icon-link img {
  min-width: 1.75rem;
}

.site-main .note {
  padding: 0.85rem 1rem;
  border-left: 4px solid var(--accent);
  background: rgba(31, 58, 95, 0.06);
}

.site-main .toggle-button {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0;
  border: 0;
  background: none;
  color: var(--link);
  font: inherit;
  text-align: left;
  cursor: pointer;
}

.site-main .toggle-button:hover,
.site-main .toggle-button:focus {
  color: var(--link-hover);
  text-decoration: underline;
}

.site-main .toggle-button[aria-expanded="true"] {
  font-weight: 700;
}

.site-main .toggle-button::before {
  content: "+";
  font-weight: 700;
}

.site-main .toggle-button[aria-expanded="true"]::before {
  content: "-";
}

.redirect-page {
  max-width: 36rem;
  margin: 4rem auto;
  padding: 2rem;
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

@media (max-width: 900px) {
  .site-shell {
    grid-template-columns: 1fr;
  }

  .site-sidebar {
    border-right: 0;
    border-bottom: 1px solid var(--border);
    padding-bottom: 1.5rem;
  }

  .sidebar-inner {
    position: static;
    max-height: none;
    overflow: visible;
  }

  .site-main .layout {
    grid-template-columns: 1fr;
  }

  .site-main .side-image {
    justify-self: start;
  }
}

@media (max-width: 640px) {
  body {
    font-size: 0.98rem;
  }

  .site-main {
    padding-top: 1.5rem;
  }

  .site-main .course-header {
    padding: 0.9rem 1rem;
  }

  dl {
    grid-template-columns: 1fr;
  }
}