/* ==========================================================================
   Tuan-Hung Vu — academic homepage
   ========================================================================== */

:root {
  --bg: #ffffff;
  --bg-soft: #f6f7f9;
  --surface: #ffffff;
  --text: #1a1d23;
  --text-soft: #4a5160;
  --muted: #6b7280;
  --border: #e5e7eb;
  --accent: #1d4ed8;
  --accent-soft: #e8eefc;
  --accent-text: #1e40af;
  --badge-muted-bg: #f1f2f4;
  --badge-muted-text: #4b5563;
  --shadow: 0 1px 2px rgba(16, 24, 40, .04), 0 1px 3px rgba(16, 24, 40, .06);
  --radius: 10px;
  --maxw: 960px;
  --font-sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1115;
    --bg-soft: #161a20;
    --surface: #151920;
    --text: #e6e8ec;
    --text-soft: #b8bec9;
    --muted: #8b93a1;
    --border: #262c36;
    --accent: #7aa2ff;
    --accent-soft: #1a2540;
    --accent-text: #a9c1ff;
    --badge-muted-bg: #1f242c;
    --badge-muted-text: #aab1bd;
    --shadow: none;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0f1115;
  --bg-soft: #161a20;
  --surface: #151920;
  --text: #e6e8ec;
  --text-soft: #b8bec9;
  --muted: #8b93a1;
  --border: #262c36;
  --accent: #7aa2ff;
  --accent-soft: #1a2540;
  --accent-text: #a9c1ff;
  --badge-muted-bg: #1f242c;
  --badge-muted-text: #aab1bd;
  --shadow: none;
  color-scheme: dark;
}

/* Base
   ========================================================================== */

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

html { scroll-behavior: smooth; scroll-padding-top: 72px; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 2px; }
a:focus-visible, button:focus-visible, summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

img { max-width: 100%; display: block; }

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

/* Top bar
   ========================================================================== */

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.topbar__inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  gap: 24px;
}
.brand {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--text);
  white-space: nowrap;
}
.brand:hover { text-decoration: none; }
.nav { display: flex; gap: 4px; margin-left: auto; overflow-x: auto; scrollbar-width: none; }
.nav::-webkit-scrollbar { display: none; }
.nav a {
  color: var(--text-soft);
  font-size: .9rem;
  font-weight: 500;
  padding: 6px 10px;
  border-radius: 6px;
  white-space: nowrap;
}
.nav a:hover, .nav a.is-active { color: var(--text); background: var(--bg-soft); text-decoration: none; }
.theme-toggle {
  flex: none;
  width: 34px;
  height: 34px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-soft);
  cursor: pointer;
}
.theme-toggle:hover { color: var(--text); }

/* Hero
   ========================================================================== */

.hero {
  display: grid;
  grid-template-columns: 168px 1fr;
  gap: 36px;
  align-items: center;
  padding: 56px 0 28px;
}
.hero__photo {
  width: 168px;
  height: 168px;
  border-radius: 50%;
  object-fit: cover;
  border: 4px solid var(--surface);
  box-shadow: 0 0 0 1px var(--border), var(--shadow);
}
.hero__name {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 2.4rem;
  line-height: 1.15;
  letter-spacing: -.01em;
  margin: 0 0 10px;
}
.hero__roles { list-style: none; margin: 0 0 10px; padding: 0; color: var(--text-soft); font-size: 1.02rem; }
.hero__meta { display: flex; flex-wrap: wrap; gap: 6px 20px; margin: 0 0 16px; color: var(--muted); font-size: .92rem; }
.hero__meta i { margin-right: 4px; }
.hero__links { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; margin: 0; padding: 0; }

.chip-link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text);
  font-size: .88rem;
  font-weight: 500;
  transition: border-color .15s, color .15s, background .15s;
}
.chip-link i { color: var(--muted); transition: color .15s; }
.chip-link:hover { text-decoration: none; border-color: var(--accent); color: var(--accent); }
.chip-link:hover i { color: var(--accent); }

/* Sections
   ========================================================================== */

.section { padding: 28px 0; border-top: 1px solid var(--border); }
.section--bio { border-top: 0; padding-top: 4px; }
.section__head { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.section__title {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.55rem;
  letter-spacing: -.005em;
  margin: 0 0 16px;
}
.section__head .section__title { margin-bottom: 0; }
.section__lead { color: var(--muted); font-size: .92rem; margin: 6px 0 18px; }

.prose { color: var(--text-soft); font-size: 1.02rem; max-width: 72ch; }
.prose p { margin: 0 0 12px; }

.tags { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; padding: 0; margin: 16px 0 0; }
.tags li {
  background: var(--accent-soft);
  color: var(--accent-text);
  font-size: .82rem;
  font-weight: 500;
  padding: 4px 11px;
  border-radius: 999px;
}

/* News
   ========================================================================== */

.news { list-style: none; margin: 0; padding: 0; }
.news__item {
  display: grid;
  grid-template-columns: 76px 1fr;
  gap: 16px;
  padding: 7px 0;
  font-size: .95rem;
  color: var(--text-soft);
}
.news__item time, .timeline time {
  font-variant-numeric: tabular-nums;
  color: var(--muted);
  font-size: .86rem;
  font-weight: 500;
  padding-top: 2px;
}
.news__item strong { color: var(--text); font-weight: 600; }

.more { margin-top: 8px; }
.more summary {
  cursor: pointer;
  color: var(--accent);
  font-size: .9rem;
  font-weight: 500;
  list-style: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 0;
}
.more summary::-webkit-details-marker { display: none; }
.more summary::before { content: "+"; font-weight: 600; width: 1ch; }
.more[open] summary::before { content: "−"; }
.more[open] summary { margin-bottom: 4px; }
.more .news { max-height: 420px; overflow-y: auto; padding-right: 8px; }

/* Publications
   ========================================================================== */

.segmented {
  display: inline-flex;
  padding: 3px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 9px;
}
.segmented button {
  border: 0;
  background: transparent;
  color: var(--text-soft);
  font: 500 .86rem var(--font-sans);
  padding: 5px 12px;
  border-radius: 6px;
  cursor: pointer;
}
.segmented button[aria-pressed="true"] { background: var(--surface); color: var(--text); box-shadow: var(--shadow), 0 0 0 1px var(--border); }

.pubs__year { display: grid; grid-template-columns: 76px 1fr; gap: 16px; }
.pubs__year + .pubs__year { margin-top: 6px; }
.pubs__yearlabel {
  margin: 0;
  padding-top: 16px;
  font-size: .95rem;
  font-weight: 600;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  position: sticky;
  top: 64px;
  align-self: start;
}
.pubs__list { list-style: none; margin: 0; padding: 0; }
.pub {
  display: grid;
  grid-template-columns: 208px 1fr;
  gap: 22px;
  align-items: start;
  padding: 18px 0;
  border-bottom: 1px dashed var(--border);
}
.pub__thumb {
  display: block;
  aspect-ratio: 8 / 5;
  border-radius: 8px;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  transition: transform .2s ease, box-shadow .2s ease;
}
.pub__thumb img { width: 100%; height: 100%; object-fit: cover; }
.pub__thumb:hover { transform: translateY(-2px); box-shadow: 0 6px 18px rgba(16, 24, 40, .12); }
.pub__meta { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 8px; margin-top: 7px; }
.pub__meta .badge { margin-top: 0; }
.pubs__year:last-child .pub:last-child { border-bottom: 0; }
.pubs[data-mode="selected"] .pub:not(.is-selected),
.pubs[data-mode="selected"] .pubs__year.is-empty { display: none; }
.pubs[data-mode="selected"] .pubs__year { grid-template-columns: 1fr; gap: 0; margin-top: 0; }
.pubs[data-mode="selected"] .pubs__yearlabel { display: none; }

.badge {
  display: inline-block;
  max-width: 100%;
  background: var(--accent-soft);
  color: var(--accent-text);
  font-size: .76rem;
  font-weight: 600;
  line-height: 1.35;
  padding: 4px 9px;
  border-radius: 6px;
  margin-top: 2px;
}
.badge--muted { background: var(--badge-muted-bg); color: var(--badge-muted-text); }

.pub__title { display: block; color: var(--text); font-weight: 600; font-size: 1rem; line-height: 1.4; }
.pub__title:hover { color: var(--accent); }
.pub__authors { color: var(--text-soft); font-size: .9rem; margin-top: 3px; }
.pub__authors strong { color: var(--text); font-weight: 600; }
.pub__links { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 14px; margin-top: 7px; font-size: .84rem; }
.pub__links a { color: var(--text-soft); font-weight: 500; }
.pub__links a i { color: var(--muted); margin-right: 3px; }
.pub__links a:hover, .pub__links a:hover i { color: var(--accent); text-decoration: none; }
/* Code link with star count: split pill, count on a filled accent segment. */
.pub__links a.has-stars { display: inline-flex; align-items: stretch; overflow: hidden; border: 1px solid var(--accent); border-radius: 6px; line-height: 1.6; }
.has-stars__label { display: inline-flex; align-items: center; padding: 0 8px; background: var(--accent-soft); color: var(--accent-text); }
.pub__links a.has-stars .has-stars__label i { color: var(--accent-text); }
.pub__links .stars { display: inline-flex; align-items: center; gap: 3px; padding: 0 7px; background: var(--accent); color: var(--bg); font-size: .78rem; font-weight: 600; font-variant-numeric: tabular-nums; }
.pub__links a.has-stars .stars i { margin-right: 0; color: var(--bg); font-size: .68rem; }
.pub__links a.has-stars:hover .has-stars__label, .pub__links a.has-stars:hover .has-stars__label i { color: var(--accent); }
.pub__links a.has-stars:hover .stars { filter: brightness(1.12); }
.pub__note {
  color: #b45309;
  background: color-mix(in srgb, #f59e0b 14%, transparent);
  font-weight: 600;
  font-size: .76rem;
  padding: 2px 8px;
  border-radius: 6px;
}
:root[data-theme="dark"] .pub__note { color: #fbbf24; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .pub__note { color: #fbbf24; } }

/* Service, talks, awards
   ========================================================================== */

.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  box-shadow: var(--shadow);
}
.card__title { margin: 0 0 10px; font-size: .8rem; font-weight: 600; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); }
.plain { list-style: none; margin: 0; padding: 0; font-size: .94rem; }
.plain li { padding: 5px 0; }
.plain li + li { border-top: 1px solid var(--border); }
.kv { margin: 0; font-size: .94rem; }
.kv dt { font-weight: 600; margin-top: 8px; }
.kv dt:first-child { margin-top: 0; }
.kv dd { margin: 2px 0 0; color: var(--text-soft); }

.timeline { list-style: none; margin: 0; padding: 0; }
.timeline li {
  display: grid;
  grid-template-columns: 52px 1fr;
  gap: 14px;
  padding: 6px 0;
  font-size: .94rem;
  color: var(--text-soft);
}
.timeline strong { color: var(--text); font-weight: 600; }

/* Footer
   ========================================================================== */

.footer { border-top: 1px solid var(--border); margin-top: 32px; }
.footer__inner { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px; padding-top: 22px; padding-bottom: 32px; color: var(--muted); font-size: .85rem; }

/* Simple pages (404 etc.)
   ========================================================================== */

.page { padding: 72px 0; }
.page h1 { font-family: var(--font-serif); font-size: 2rem; margin: 0 0 12px; }

/* Responsive
   ========================================================================== */

@media (max-width: 760px) {
  .container, .topbar__inner { padding-left: 16px; padding-right: 16px; }
  .topbar__inner { gap: 12px; }
  .brand { display: none; }
  .nav { margin-left: -6px; }
  .theme-toggle { margin-left: auto; }

  .hero { grid-template-columns: 1fr; gap: 20px; padding-top: 32px; text-align: left; }
  .hero__photo { width: 120px; height: 120px; }
  .hero__name { font-size: 2rem; }

  .grid-2 { grid-template-columns: 1fr; gap: 24px; }

  .news__item { grid-template-columns: 64px 1fr; gap: 12px; }
  .pubs__year { grid-template-columns: 1fr; gap: 0; }
  .pubs__yearlabel { position: static; padding-top: 14px; }
  .pub { grid-template-columns: 1fr; gap: 12px; }
  .pub__thumb { max-width: 320px; }
}

@media print {
  .topbar, .segmented, .more summary, .footer { display: none; }
  .pubs[data-mode="selected"] .pub, .pubs[data-mode="selected"] .pubs__year { display: grid !important; }
  .pubs[data-mode="selected"] .pubs__year { grid-template-columns: 76px 1fr !important; gap: 16px !important; }
  .pubs[data-mode="selected"] .pubs__yearlabel { display: block !important; }
  .more .news { max-height: none; }
}