:root {
  --ink: #1a1a1a;
  --muted: #555;
  --faint: #888;
  --line: #e3e3e3;
  --accent: #6b4fa0;
  --bg: #ffffff;
  --max: 920px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: 'Nunito', sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

/* Header / nav */
.site-header {
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(6px);
  z-index: 10;
}
.site-header .wrap {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding-top: 18px;
  padding-bottom: 18px;
  gap: 16px;
  flex-wrap: wrap;
}
.brand {
  font-size: 20px;
  font-weight: 700;
  color: var(--ink);
  text-decoration: none;
  letter-spacing: 0.2px;
}
.nav {
  display: flex;
  gap: 22px;
}
.nav a {
  font-size: 16px;
  color: var(--muted);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: 2px solid transparent;
}
.nav a:hover { color: var(--ink); }
.nav a.active {
  color: var(--ink);
  border-bottom-color: var(--accent);
}

/* Main */
main { padding: 48px 0 80px; }

h1.page-title {
  font-size: 40px;
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 26px;
}
@media (max-width: 640px) { h1.page-title { font-size: 32px; } }

p { margin-bottom: 16px; font-size: 16px; }
a { color: var(--accent); }

/* About layout */
.about-grid {
  display: flex;
  gap: 40px;
  align-items: flex-start;
}
.about-text { flex: 1 1 0; min-width: 0; }
.about-photo { flex: 0 0 300px; }
.about-photo img {
  width: 100%;
  height: auto;
  border-radius: 8px;
  display: block;
}
.links { margin-top: 24px; }
.links p { margin-bottom: 6px; font-size: 15px; }
@media (max-width: 720px) {
  .about-grid { flex-direction: column; gap: 24px; }
  .about-photo { flex: 1 1 auto; max-width: 340px; }
}

/* Section headings */
.section-title {
  font-size: 22px;
  font-weight: 700;
  margin: 34px 0 10px;
}
.section-title:first-of-type { margin-top: 0; }

/* Page intro photo */
.page-photo {
  border-radius: 8px;
  display: block;
  margin: 0 0 32px;
}
.page-photo.landscape { width: 100%; max-width: 360px; height: auto; }
.page-photo.portrait { width: 100%; max-width: 320px; height: auto; }

/* Papers (details/summary accordion) */
.paper {
  border-bottom: 1px solid var(--line);
}
.paper summary {
  list-style: none;
  cursor: pointer;
  display: grid;
  grid-template-columns: 21px 1fr;
  column-gap: 10px;
  padding: 11px 0;
  font-size: 15px;
  line-height: 1.45;
}
.paper summary::-webkit-details-marker { display: none; }
.paper summary::before {
  content: "\25B6";
  font-size: 11px;
  color: var(--faint);
  transition: transform 0.18s ease;
  line-height: 1.6;
  font-weight: 400;
  grid-row: 1;
  grid-column: 1;
}
.ptitle { font-weight: 700; grid-column: 2; }
.paper[open] summary::before { transform: rotate(90deg); }
.coauthors { grid-column: 2; font-weight: 400; font-size: 13px; color: var(--muted); margin-top: 3px; }
.coauthors a { color: var(--accent); }
.venue { grid-column: 2; font-weight: 400; font-size: 13px; font-style: italic; color: var(--muted); margin-top: 2px; }
.pbody { padding: 0 0 14px 21px; }
.authors { font-size: 12px; color: var(--muted); margin-bottom: 6px; }
.abstract { font-size: 13px; line-height: 1.65; color: #2a2a2a; }

/* Talks list */
.talk {
  padding: 11px 0;
  border-bottom: 1px solid var(--line);
  font-size: 15px;
}
.ttitle { font-weight: 700; }
.tmeta { font-weight: 400; color: var(--muted); }
.tmeta a { color: var(--accent); }
.tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  border-radius: 4px;
  padding: 1px 7px;
  margin-left: 6px;
  vertical-align: 1px;
  white-space: nowrap;
}
.tag.invited { color: var(--accent); border: 1px solid #cfc2e6; }
.tag.plain { color: var(--muted); border: 1px solid #d8d8d8; }
.tag.cancelled { color: #999; border: 1px solid #d8d8d8; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 24px 0;
  font-size: 13px;
  color: var(--faint);
}