:root {
  --bg: #f6f7f4;
  --surface: #ffffff;
  --text: #1c2329;
  --muted: #5a6672;
  --accent: #2f5d8a;
  --border: #d8dee6;
  --shadow: 0 1px 2px rgba(20, 30, 40, 0.06), 0 8px 24px rgba(20, 30, 40, 0.04);
  --header-bg: rgba(246, 247, 244, 0.88);
  --grid-line: rgba(44, 62, 80, 0.05);
  --tag-bg: #eef2f6;
  --header-padding-y: 1.2rem;
  --header-title-size: 1.22rem;
  --header-subtitle-size: 0.92rem;
  --header-nav-size: 0.98rem;
  /* Header uses sans at heavier weights — small serif titles often look “skinny” */
  --font-header: "IBM Plex Sans", system-ui, sans-serif;
  --font-sans: "IBM Plex Sans", system-ui, sans-serif;
  --font-serif: "IBM Plex Serif", Georgia, serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;
}

[data-theme="dark"] {
  --bg: #12171c;
  --surface: #1a222b;
  --text: #e8edf2;
  --muted: #9aa7b5;
  --accent: #8eb6df;
  --border: #2b3642;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.35), 0 10px 28px rgba(0, 0, 0, 0.25);
  --header-bg: rgba(18, 23, 28, 0.9);
  --grid-line: rgba(255, 255, 255, 0.04);
  --tag-bg: #24303b;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: var(--font-sans);
  font-size: 1.02rem;
  line-height: 1.68;
  color: var(--text);
  background-color: var(--bg);
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 34px 34px;
}

main {
  flex: 1 0 auto;
  padding: 2rem 0 3rem;
}

.container {
  width: min(1080px, calc(100% - 2rem));
  margin: 0 auto;
}

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

h1,
h2,
h3 {
  font-family: var(--font-serif);
  line-height: 1.2;
  letter-spacing: -0.02em;
  font-weight: 600;
}

h1 {
  font-size: clamp(1.9rem, 3vw, 2.6rem);
  margin: 0 0 1rem;
}

h2 {
  font-size: clamp(1.35rem, 2.2vw, 1.75rem);
  margin: 2rem 0 0.75rem;
}

h3 {
  font-size: 1.08rem;
  margin: 0 0 0.45rem;
}

p {
  margin: 0 0 0.9rem;
}

.muted {
  color: var(--muted);
}

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

a:hover {
  text-decoration-thickness: 2px;
}

.iconify {
  width: 1.1em;
  height: 1.1em;
  vertical-align: text-bottom;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--border);
  background: var(--header-bg);
  backdrop-filter: blur(8px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
  padding: var(--header-padding-y) 0;
  min-height: 3.35rem;
}

.site-brand {
  display: flex;
  flex-direction: column;
  gap: 0.22rem;
  min-width: 0;
}

.site-title {
  font-family: var(--font-header);
  font-size: var(--header-title-size);
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.25;
  color: var(--text);
  text-decoration: none;
  font-synthesis: none;
}

.site-subtitle {
  font-family: var(--font-header);
  font-size: var(--header-subtitle-size);
  font-weight: 500;
  letter-spacing: 0.01em;
  line-height: 1.35;
  color: var(--muted);
  text-decoration: none;
}

.site-subtitle:hover {
  color: var(--accent);
}

.nav-toggle {
  display: none;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  border-radius: 0.5rem;
  padding: 0.5rem 0.65rem;
  cursor: pointer;
}

.nav-toggle .iconify {
  width: 1.35rem;
  height: 1.35rem;
}

.nav-controls {
  display: flex;
  align-items: center;
  gap: 1.35rem;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem 1.1rem;
}

.site-nav a {
  font-family: var(--font-header);
  color: var(--muted);
  text-decoration: none;
  font-size: var(--header-nav-size);
  font-weight: 500;
  letter-spacing: 0.02em;
  padding: 0.25rem 0;
}

.site-nav a:hover {
  color: var(--text);
}

.theme-switch {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  user-select: none;
  color: var(--muted);
}

.theme-switch:focus-within {
  outline: 2px solid var(--accent);
  outline-offset: 0.25rem;
  border-radius: 999px;
}

.theme-switch input {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  margin: 0;
  opacity: 0;
  cursor: pointer;
  z-index: 2;
}

.theme-track {
  --track-w: 2.85rem;
  --track-h: 1.52rem;
  --thumb-size: 1.26rem;
  width: var(--track-w);
  height: var(--track-h);
  border-radius: 999px;
  background: var(--tag-bg);
  border: 1px solid var(--border);
  position: relative;
  box-sizing: border-box;
  transition: background 0.2s ease;
}

.theme-thumb {
  position: absolute;
  top: 50%;
  left: 3px;
  width: var(--thumb-size);
  height: var(--thumb-size);
  margin-top: calc(var(--thumb-size) * -0.5);
  border-radius: 50%;
  background: var(--surface);
  border: 1px solid var(--border);
  box-sizing: border-box;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.2s ease;
  pointer-events: none;
}

.theme-mode-icon {
  position: relative;
  width: 0.72rem;
  height: 0.72rem;
  line-height: 0;
  color: var(--text);
}

.theme-mode-icon .iconify {
  width: 0.72rem;
  height: 0.72rem;
}

.theme-icon-moon {
  display: none;
}

html[data-theme="dark"] .theme-icon-sun {
  display: none;
}

html[data-theme="dark"] .theme-icon-moon {
  display: block;
}

.theme-switch input:checked + .theme-track .theme-thumb {
  transform: translateX(calc(var(--track-w) - var(--thumb-size) - 9px));
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 1.2rem 0 1.6rem;
  margin-top: auto;
}

/* Hero & homepage */
.hero {
  margin-bottom: 1.6rem;
}

.kicker {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 0.5rem;
}

.lead {
  font-size: 1.08rem;
  max-width: none;
  text-wrap: pretty;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1rem;
}

.button {
  display: inline-block;
  padding: 0.5rem 0.95rem;
  border-radius: 0.45rem;
  text-decoration: none;
  font-size: 0.92rem;
  border: 1px solid var(--border);
}

.button-primary {
  background: var(--accent);
  color: #fff;
  border-color: transparent;
}

.button-secondary {
  background: var(--surface);
  color: var(--text);
}

.group-photo {
  margin: 0 0 1.8rem;
  border-radius: 0.55rem;
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.group-photo img {
  width: 100%;
  max-height: 420px;
  object-fit: cover;
  object-position: center var(--group-photo-y, center);
  display: block;
}

.stat-strip {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.8rem;
  margin-bottom: 2rem;
}

.stat-strip article {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 0.55rem;
  padding: 0.9rem 1rem;
  box-shadow: var(--shadow);
}

.stat-strip strong {
  display: block;
  font-family: var(--font-serif);
  font-size: 1.35rem;
  margin-bottom: 0.2rem;
}

.feature-grid,
.resource-grid,
.cards,
.team-grid,
.materials-list,
.publication-list {
  display: grid;
  gap: 0.85rem;
  margin-bottom: 2rem;
}

.feature-grid {
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.resource-grid {
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.card,
.feature,
.resource-card,
.publication,
.stat-strip article,
.lecture-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 0.55rem;
  box-shadow: var(--shadow);
}

.feature,
.resource-card {
  padding: 1rem 1.05rem;
}

.callout {
  margin-top: 1.5rem;
  padding: 1.1rem 1.15rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 0.55rem;
  box-shadow: var(--shadow);
}

/* Publications */
.year-group {
  margin-bottom: 1.5rem;
}

.year-heading {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  letter-spacing: 0.04em;
  color: var(--muted);
  margin-bottom: 0.6rem;
}

.publication-list {
  grid-template-columns: 1fr;
}

.publication-rich {
  padding: 0.95rem 1.05rem;
}

.publication-type {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
  margin: 0 0 0.35rem;
}

.publication-meta span {
  font-style: italic;
}

.publication-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem 1rem;
  margin-top: 0.5rem;
}

.publication-links a {
  font-size: 0.9rem;
  text-decoration: none;
}

/* Team */
.team-page-title {
  margin-bottom: 1.6rem;
}

.team-role-group + .team-role-group {
  margin-top: 1.8rem;
}

.team-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.team-card {
  display: grid;
  grid-template-columns: 7.4rem 1fr;
  gap: 0;
  padding: 0;
  overflow: hidden;
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 0.55rem;
  box-shadow: var(--shadow);
}

.team-portrait-wrap {
  min-height: 100%;
  display: flex;
  align-items: stretch;
}

.portrait {
  width: 100%;
  height: 100%;
  min-height: 9rem;
  object-fit: cover;
  display: block;
}

.avatar {
  width: 100%;
  min-height: 9rem;
  display: grid;
  place-items: center;
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 600;
  color: var(--accent);
  background: var(--tag-bg);
}

.team-card-content {
  padding: 0.85rem 0.95rem 0.95rem;
  position: relative;
}

.team-card h3 {
  margin: 0 0 0.2rem;
}

.team-card .role {
  margin: 0;
}

.team-header-actions {
  position: absolute;
  top: 0.7rem;
  right: 0.75rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  justify-content: flex-end;
}

.team-action-icon {
  display: inline-grid;
  place-items: center;
  width: 2.15rem;
  height: 2.15rem;
  border-radius: 0.45rem;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  text-decoration: none;
}

.team-action-icon:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.team-action-icon .iconify {
  width: 1.15rem;
  height: 1.15rem;
}

.team-bio {
  margin-top: 0.65rem;
  padding-top: 0.55rem;
  border-top: 1px solid var(--border);
}

.team-bio p {
  margin: 0;
  font-size: 0.92rem;
}

.alumni-card {
  display: flex;
  align-items: center;
  padding: 0.75rem 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 0.55rem;
  box-shadow: var(--shadow);
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
}

.alumni-card:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* Teaching */
.lecture-card {
  padding: 1.15rem 1.2rem 1.3rem;
  margin-top: 1.15rem;
  margin-bottom: 1.35rem;
}

.lecture-image {
  width: 100%;
  max-height: 280px;
  object-fit: cover;
  border-radius: 0.5rem;
  border: 1px solid var(--border);
  margin-bottom: 0.85rem;
}

.lecture-card h3 {
  margin-top: 0.8rem;
  margin-bottom: 0.5rem;
}

.lecture-meta {
  margin-top: -0.35rem;
  margin-bottom: 0.75rem;
}

.materials-grid .materials-card h3 {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* Responsive */
@media (max-width: 860px) {
  .nav-toggle {
    display: inline-grid;
    place-items: center;
  }

  .nav-controls {
    display: none;
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0.75rem;
    padding: 1rem 1.15rem 1.15rem;
    background: var(--header-bg);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(8px);
  }

  .nav-controls.is-open {
    display: flex;
  }

  .site-header {
    position: relative;
  }

  .header-inner {
    position: relative;
    flex-wrap: wrap;
  }

  .site-nav {
    flex-direction: column;
    gap: 0.5rem;
  }

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

  .team-card {
    grid-template-columns: 1fr;
  }

  .team-portrait-wrap {
    max-height: 220px;
    overflow: hidden;
  }

  .portrait,
  .avatar {
    min-height: 220px;
  }

  .team-header-actions {
    position: static;
    margin-top: 0.5rem;
    justify-content: flex-start;
  }

  .stat-strip {
    grid-template-columns: 1fr;
  }
}