/* ── Reset & base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f8f6f3;
  --color-text: #1a1a2e;
  --color-text-muted: #5a6a7a;
  --color-accent: #c2410c;
  --color-accent-hover: #9a3412;
  --color-border: #e2e8f0;
  --color-award: #b45309;
  --color-award-bg: #fef3c7;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --max-width: 1100px;
  --radius: 8px;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.65;
  font-size: 16px;
}

a { color: var(--color-accent); text-decoration: none; }
a:hover { color: var(--color-accent-hover); text-decoration: underline; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ── Nav ── */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

nav .logo {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-text);
  display: flex;
  align-items: center;
}
nav .logo:hover { text-decoration: none; }

.logo-img {
  height: 36px;
  width: auto;
  display: block;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 24px;
}

nav ul a {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  font-weight: 500;
}
nav ul a:hover, nav ul a.active { color: var(--color-accent); text-decoration: none; }

/* ── Hero ── */
#hero {
  padding: 96px 0 80px;
  background: var(--color-bg-alt);
  text-align: center;
}

#hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

#hero .tagline {
  font-size: 1.1rem;
  color: var(--color-text-muted);
  max-width: 720px;
  margin: 0 auto 12px;
}

#hero .affiliation {
  font-size: 0.88rem;
  color: var(--color-text-muted);
  margin-bottom: 32px;
  font-style: italic;
}

.btn {
  display: inline-block;
  background: var(--color-accent);
  color: #fff;
  padding: 12px 28px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  transition: background 0.15s;
}
.btn:hover { background: var(--color-accent-hover); color: #fff; text-decoration: none; }

.btn-sm { padding: 8px 20px; font-size: 0.875rem; }
.btn-outline { background: transparent; color: var(--color-accent); border: 2px solid var(--color-accent); }
.btn-outline:hover { background: var(--color-accent); color: #fff; text-decoration: none; }

.hero-btns { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-top: 4px; }

/* ── Sections ── */
section { padding: 72px 0; }
section.bg-alt { background: var(--color-bg-alt); }

section h2 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 40px;
  letter-spacing: -0.01em;
}

/* ── Research cards ── */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-top: 3px solid var(--color-accent);
  border-radius: var(--radius);
  padding: 28px;
}

.card h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.card p { color: var(--color-text-muted); font-size: 0.93rem; }

/* ── People ── */
.role-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
  margin: 44px 0 16px;
}

.people-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 24px;
}

.people-grid-sm {
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 12px;
}

.person { text-align: center; }

.avatar {
  width: 110px;
  height: 110px;
  border-radius: 50%;
  background: var(--color-border);
  margin: 0 auto 12px;
}

.person h4 { font-size: 0.95rem; font-weight: 600; margin-bottom: 4px; }
.person .role { font-size: 0.85rem; color: var(--color-text-muted); }
.person .affiliation-small { font-size: 0.82rem; color: var(--color-text-muted); margin-top: 2px; }
.person .research-interest { font-size: 0.82rem; color: var(--color-text-muted); margin-top: 2px; }

.person-sm { text-align: center; padding: 12px; background: var(--color-bg); border: 1px solid var(--color-border); border-radius: var(--radius); }
.person-sm h4 { font-size: 0.88rem; font-weight: 600; margin-bottom: 6px; }

.person .links { margin-top: 10px; display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }
.person .links a { font-size: 0.82rem; }

/* ── Alumni ── */
.alumni { margin-top: 32px; display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 24px; }
.alumni-group h4 { font-size: 0.85rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.07em; color: var(--color-text-muted); margin-bottom: 10px; }
.alumni-group ul { list-style: none; }
.alumni-group li { font-size: 0.9rem; margin-bottom: 6px; }
.alumni-group p { font-size: 0.9rem; color: var(--color-text-muted); }

/* ── News ── */
.news-list { list-style: none; display: flex; flex-direction: column; gap: 0; }

.news-item {
  display: flex;
  align-items: baseline;
  gap: 20px;
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
}
.news-item:last-child { border-bottom: none; }

.news-date {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-text-muted);
  min-width: 72px;
  flex-shrink: 0;
}

.news-body { display: flex; flex-direction: column; gap: 2px; }
.news-title { font-size: 0.97rem; font-weight: 500; color: var(--color-text); }
.news-source { font-size: 0.82rem; color: var(--color-text-muted); }

/* ── Publications ── */
.pub-year {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
}

.pub-year summary {
  font-size: 1rem;
  font-weight: 700;
  padding: 14px 20px;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--color-bg);
  user-select: none;
}
.pub-year summary::-webkit-details-marker { display: none; }
.pub-year summary::before {
  content: "▸";
  font-size: 0.75rem;
  color: var(--color-text-muted);
  transition: transform 0.15s;
}
.pub-year[open] summary::before { transform: rotate(90deg); }
.pub-year summary:hover { background: var(--color-bg-alt); }

.pub-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  padding: 4px 20px 16px;
  background: var(--color-bg);
}

.pub {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 14px 0;
  border-bottom: 1px solid var(--color-border);
}
.pub:last-child { border-bottom: none; }

.pub-title { font-weight: 600; font-size: 0.97rem; }
.pub-authors { font-size: 0.86rem; color: var(--color-text-muted); }
.pub-venue { font-size: 0.86rem; color: var(--color-text-muted); font-style: italic; }
.pub-links { display: flex; gap: 12px; margin-top: 4px; }
.pub-links a { font-size: 0.82rem; }

.award {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: var(--color-award-bg);
  color: var(--color-award);
  padding: 2px 6px;
  border-radius: 4px;
  vertical-align: middle;
  margin-left: 6px;
}

/* ── People photos ── */
.avatar-img {
  width: 110px;
  height: 110px;
  border-radius: 50%;
  object-fit: cover;
  margin: 0 auto 12px;
  display: block;
  background: var(--color-border);
}
.avatar-img-sm { width: 64px; height: 64px; }

/* Show a neutral circle when the image file isn't there yet */
.avatar-img[src$=".jpg"]:not([complete]),
.avatar-img { background: var(--color-border); }

/* ── Blog ── */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
}

.blog-card {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: var(--color-bg-alt);
}

.blog-img {
  width: 100%;
  aspect-ratio: 4 / 3;
  background-size: cover;
  background-position: center;
}

.blog-img-placeholder { background-color: var(--color-border); }

.blog-caption {
  padding: 10px 12px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-text);
}

/* ── Materials ── */
.materials-list { display: flex; flex-direction: column; gap: 20px; }

.material-item {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
}

.material-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
  flex-wrap: wrap;
}

.material-header h3 { font-size: 1.05rem; font-weight: 600; }

.material-tag {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  padding: 2px 8px;
  border-radius: 4px;
}

.material-item p { font-size: 0.93rem; color: var(--color-text-muted); }

/* ── Contact ── */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 40px;
  margin-bottom: 32px;
}
.contact-grid h3 { font-size: 1rem; font-weight: 700; margin-bottom: 10px; }
.contact-grid p { color: var(--color-text-muted); font-size: 0.93rem; margin-bottom: 4px; }
.contact-list { list-style: none; margin-top: 12px; }
.contact-list li { font-size: 0.93rem; margin-bottom: 8px; }
.contact-address { font-size: 0.85rem; color: var(--color-text-muted); border-top: 1px solid var(--color-border); padding-top: 20px; }

/* ── Footer ── */
footer {
  padding: 24px 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
  font-size: 0.82rem;
  color: var(--color-text-muted);
}

/* ── Hamburger ── */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
}

/* ── Responsive ── */
@media (max-width: 640px) {
  .nav-toggle { display: flex; }
  nav ul {
    display: none;
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    padding: 16px 24px;
    gap: 16px;
    z-index: 99;
  }
  nav ul.open { display: flex; }
  nav ul a { font-size: 0.95rem; }
  #hero { padding: 64px 0 48px; }
  section { padding: 52px 0; }
  .news-item { flex-direction: column; gap: 4px; }
  .news-date { min-width: unset; }
}