:root {
  --bg: #f3f6fa;
  --surface: #ffffff;
  --surface-muted: #eef3f9;
  --text: #172033;
  --text-soft: #4f5b73;
  --primary: #1f3f75;
  --primary-strong: #0f2952;
  --border: #d8e0ec;
  --radius-lg: 16px;
  --radius-md: 12px;
  --shadow: 0 8px 24px rgba(23, 32, 51, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Inter", system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 1rem;
  padding: 0.5rem 0.75rem;
  border-radius: 8px;
  background: var(--primary-strong);
  color: #fff;
  z-index: 1000;
}

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 999;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.9rem 1.25rem;
  background: linear-gradient(110deg, var(--primary-strong), var(--primary));
  color: #fff;
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.topbar__brand {
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

.brand-mark {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: #ffffff;
  padding: 6px;
  box-shadow: 0 4px 12px rgba(23, 32, 51, 0.08);
  border: 1px solid var(--border);
  display: inline-block;
}

.brand-title {
  margin: 0;
  font-weight: 700;
}

.brand-subtitle {
  margin: 0;
  font-size: 0.85rem;
  opacity: 0.9;
}

.menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 40px;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.35);
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  padding: 0;
  cursor: pointer;
}

.menu-toggle .hamburger {
  display: block;
}

.menu-toggle .line {
  transition: transform 240ms cubic-bezier(.2,.9,.2,1), opacity 180ms ease;
  transform-origin: center;
  stroke: currentColor;
}

.menu-toggle[aria-expanded="true"] .line1 {
  transform: translateY(6px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .line2 {
  opacity: 0;
  transform: scaleX(0);
}

.menu-toggle[aria-expanded="true"] .line3 {
  transform: translateY(-6px) rotate(-45deg);
}

.layout {
  display: grid;
  grid-template-columns: 300px minmax(0, 1fr);
  min-height: calc(100vh - 73px);
}

.sidebar {
  position: sticky;
  top: 73px;
  align-self: start;
  height: calc(100vh - 73px);
  padding: 1.25rem 1rem;
  overflow: auto;
  background: var(--surface);
  border-right: 1px solid var(--border);
}

.nav-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.25rem;
}

.nav-list li {
  list-style: none;
}

.nav-list a {
  display: block;
  padding: 0.6rem 0.75rem;
  border-radius: 10px;
  color: var(--text-soft);
  text-decoration: none;
  font-weight: 500;
  border: 1px solid transparent;
  transition: all 180ms ease;
}

.nav-list__section {
  font-weight: 800;
  color: var(--primary-strong);
  font-size: 1rem;
  padding: 0.75rem 0.85rem;
  margin-top: 0.5rem;
  letter-spacing: -0.01em;
}

.nav-list__subsection {
  padding-left: 2.8rem;
  font-size: 0.86rem;
  position: relative;
  font-weight: 400;
  color: var(--text-soft);
  padding-top: 0.5rem;
  padding-bottom: 0.5rem;
}

.nav-list__meta {
  font-size: 0.86rem;
  color: var(--text-soft);
  opacity: 0.75;
  font-weight: 400;
}

.nav-list__separator {
  height: 1px;
  background: var(--border);
  margin: 0.8rem 0.5rem;
  list-style: none;
}

.nav-list a:hover,
.nav-list a:focus-visible {
  background: var(--surface-muted);
  color: var(--primary-strong);
  border-color: var(--border);
  transform: translateX(2px);
}

.nav-list a.active {
  background: #e5edf9;
  color: var(--primary-strong);
  border-color: #bfd0ee;
  font-weight: 600;
}

.nav-list__section.active {
  background: linear-gradient(110deg, #e5edf9, #d8e6fc);
  font-weight: 900;
  border-left: 3px solid var(--primary);
  padding-left: 0.75rem;
}

.nav-list__subsection.active {
  font-weight: 600;
  color: var(--primary-strong);
}

.content {
  padding: 1.4rem;
  display: grid;
  gap: 1rem;
}

.portal-main {
  max-width: 980px;
  margin: 2rem auto;
}

.portal-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.portal-link {
  text-decoration: none;
  color: inherit;
}

.portal-link__head {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.portal-link h3 {
  margin: 0 0 0.2rem;
}

.portal-link p {
  margin: 0;
  color: var(--text-soft);
}

.portal-logo {
  width: 48px;
  height: 48px;
  border-radius: 10px;
  background: #fff;
  padding: 6px;
  border: 1px solid var(--border);
  box-shadow: 0 6px 18px rgba(23, 32, 51, 0.06);
}

.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.65rem 0.9rem;
  font-size: 0.92rem;
}

.breadcrumbs a {
  color: var(--primary-strong);
  text-decoration: none;
  font-weight: 600;
}

.breadcrumbs a[aria-current="page"] {
  color: var(--text-soft);
  pointer-events: none;
}

.hero {
  background: linear-gradient(145deg, #ffffff, #edf3fb);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.1rem 1.2rem;
  box-shadow: var(--shadow);
}

.eyebrow {
  margin: 0;
  color: var(--primary);
  font-weight: 700;
  font-size: 0.86rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.hero h1 {
  margin: 0.35rem 0 0.5rem;
  font-size: clamp(1.25rem, 2.2vw, 1.8rem);
}

.lead {
  margin: 0;
  color: var(--text-soft);
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1rem;
  box-shadow: var(--shadow);
}

h2,
h3,
h4 {
  margin-top: 0;
}

h2 {
  font-size: 1.22rem;
}

h3 {
  font-size: 1.08rem;
}

.requirements {
  margin-top: 0.25rem;
  color: var(--text-soft);
}

.bullet-list {
  margin: 0.4rem 0 0;
  padding-left: 1.1rem;
}

.section-anchor {
  scroll-margin-top: 92px;
}

.table-wrap {
  margin-top: 0.8rem;
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: #fff;
}

table {
  width: 100%;
  min-width: 860px;
  border-collapse: collapse;
}

thead th {
  position: sticky;
  top: 0;
  background: var(--surface-muted);
  color: var(--primary-strong);
  font-size: 0.9rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

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

tbody tr:nth-child(even) {
  background: #fafcff;
}

tbody tr:hover {
  background: #f1f6ff;
}

.source-note p {
  margin-bottom: 0;
}

.professors-list {
  list-style: none;
  padding: 0;
  margin: 1rem 0 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 0.85rem;
}

.professor-card {
  background: linear-gradient(135deg, #fafcff, #f5f8fc);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 0.9rem 1rem;
  transition: all 220ms ease;
  position: relative;
  overflow: hidden;
}

.professor-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  width: 4px;
  height: 100%;
  background: var(--primary);
  opacity: 0;
  transition: opacity 220ms ease;
}

.professor-card:hover {
  border-color: var(--primary);
  box-shadow: 0 6px 20px rgba(31, 63, 117, 0.12);
  transform: translateY(-2px);
}

.professor-card:hover::before {
  opacity: 1;
}

.professor-name {
  display: block;
  font-weight: 600;
  color: var(--text);
  font-size: 0.94rem;
  line-height: 1.4;
}

@media (max-width: 980px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .menu-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .sidebar {
    position: fixed;
    top: 73px;
    left: 0;
    width: min(320px, 92vw);
    transform: translateX(-102%);
    transition: transform 0.2s ease;
    height: calc(100vh - 73px);
    z-index: 998;
    box-shadow: var(--shadow);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .content {
    padding: 1rem;
  }

  .portal-main {
    margin: 1rem auto;
  }

  .portal-grid {
    grid-template-columns: 1fr;
  }

  table {
    min-width: 720px;
  }
}

@media (max-width: 560px) {
  .brand-subtitle {
    display: none;
  }

  .topbar {
    padding: 0.85rem 0.95rem;
  }

  .content {
    padding: 0.8rem;
  }

  .card,
  .hero {
    padding: 0.85rem;
    border-radius: 14px;
  }
}