/* Homepage styles. Plain CSS, no framework. */

:root {
  --text: #1f2328;
  --muted: #57606a;
  --faint: #6e7781;
  --line: #e4e7eb;
  --bg: #ffffff;
  --bg-soft: #f6f8fa;
  --accent: #1f5bd8;
  --accent-soft: #edf2fd;
  --note: #b42318;
  --note-soft: #fdf1f0;
  --radius: 10px;
  --maxw: 1080px;
  --header-h: 60px;
  --font: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: calc(var(--header-h) + 12px);
}
@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

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

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 2px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }
img { display: block; max-width: 100%; }
h1, h2, h3, h4 { line-height: 1.25; letter-spacing: -0.015em; }

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

.skip-link {
  position: absolute; left: 12px; top: -60px; z-index: 100;
  padding: 8px 14px; border-radius: 8px;
  background: var(--text); color: #fff; font-weight: 600;
}
.skip-link:focus { top: 10px; text-decoration: none; }

/* Header */

.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, 0.88);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.site-header .container {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  height: var(--header-h);
}
.brand { font-size: 1.05rem; font-weight: 700; color: var(--text); letter-spacing: -0.01em; white-space: nowrap; }
.brand:hover { text-decoration: none; }
.nav { display: flex; gap: 2px; }
.nav a {
  padding: 6px 11px; border-radius: 8px;
  color: var(--muted); font-size: 0.92rem; font-weight: 500; white-space: nowrap;
}
.nav a:hover { color: var(--text); background: var(--bg-soft); text-decoration: none; }
.nav a.active { color: var(--accent); background: var(--accent-soft); }

/* About */

.hero { padding: 52px 0 12px; }
.hero > .container {
  display: grid; grid-template-columns: 272px minmax(0, 1fr); gap: 56px; align-items: start;
}

.profile { text-align: center; }
.avatar {
  width: 176px; height: 176px; margin: 0 auto 20px;
  border-radius: 50%; object-fit: cover;
  box-shadow: 0 0 0 4px var(--bg), 0 0 0 5px var(--line);
}
.profile h1 { margin: 0; font-size: 1.75rem; font-weight: 700; }
.role { margin: 6px 0 20px; color: var(--muted); }

.links { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin: 0 0 26px; padding: 0; list-style: none; }
.links a {
  display: flex; align-items: center; gap: 7px;
  padding: 7px 13px; border: 1px solid var(--line); border-radius: 999px;
  color: var(--text); font-size: 0.88rem; font-weight: 500; white-space: nowrap;
  transition: background-color 0.15s, border-color 0.15s;
}
.links a:hover { background: var(--bg-soft); border-color: #cfd6de; text-decoration: none; }
.icon { width: 16px; height: 16px; flex: none; }
.icon-scholar { color: #4285f4; }
.icon-github { color: #1f2328; }
.icon-linkedin { color: #0a66c2; }
.icon-cv { color: var(--muted); }

.label {
  margin: 0 0 10px; text-align: left;
  font-size: 0.78rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--faint);
}
.contact { margin: 0; padding: 0; list-style: none; text-align: left; font-size: 0.92rem; color: var(--muted); }
.contact li { display: flex; gap: 10px; margin-bottom: 8px; }
.contact .icon { margin-top: 3px; color: var(--faint); }
.contact p { margin: 0; }

.bio { font-size: 1.02rem; }
.bio p { margin: 0 0 1em; }
.interests { display: grid; gap: 8px; margin: 0 0 36px; padding: 0; list-style: none; }
.interests li { position: relative; padding-left: 18px; }
.interests li::before {
  content: ""; position: absolute; left: 2px; top: calc(0.8em - 3px);
  width: 6px; height: 6px; border-radius: 50%; background: var(--accent);
}
.interests .tag { margin-left: 3px; }

.subhead { margin: 0 0 12px; font-size: 1.25rem; font-weight: 700; }
.news-box {
  max-height: 9.25rem; overflow-y: auto;
  border: 1px solid var(--line); border-radius: var(--radius);
}
.news { margin: 0; padding: 6px 0; list-style: none; }
.news li { display: grid; grid-template-columns: 5.25rem minmax(0, 1fr); gap: 12px; padding: 6px 18px; }
.news .date { padding-top: 2px; color: var(--muted); font-size: 0.84rem; font-weight: 500; font-variant-numeric: tabular-nums; white-space: nowrap; }
.news-box + .subhead { margin-top: 32px; }

/* Tags */

.tag {
  display: inline-block; padding: 4px 8px; border-radius: 999px;
  font-size: 0.72rem; font-weight: 600; line-height: 1; white-space: nowrap;
}
.tag.multimodal { color: #116329; background: #dcf5e3; }
.tag.genai { color: #0550ae; background: #dcedff; }
.tag.agent { color: #0a5f66; background: #d5f1f3; }
.tag.video { color: #a40e26; background: #ffe7e5; }
.tag.image { color: #7a4d00; background: #fdf0c2; }
.tag.learning { color: #424a53; background: #e8ecf0; }

/* Sections */

.section { padding: 44px 0; }
.section-title {
  margin: 0 0 20px; padding-bottom: 12px; border-bottom: 1px solid var(--line);
  font-size: 1.6rem; font-weight: 700;
}
.section-head {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px 16px;
  padding-bottom: 12px; border-bottom: 1px solid var(--line);
}
.section-head .section-title { margin: 0; padding: 0; border: 0; }
.section-note { margin: 8px 0 0; color: var(--faint); font-size: 0.85rem; text-align: right; }

/* Publications */

.tabs { display: inline-flex; gap: 2px; padding: 3px; border: 1px solid var(--line); border-radius: 10px; background: var(--bg-soft); }
.tab {
  padding: 5px 16px; border: 0; border-radius: 7px; background: transparent; cursor: pointer;
  color: var(--muted); font: inherit; font-size: 0.88rem; font-weight: 500;
}
.tab:hover { color: var(--text); }
.tab[aria-selected="true"] { background: var(--bg); color: var(--text); box-shadow: 0 1px 2px rgba(31, 35, 40, 0.12); }

.pub-year { margin-top: 30px; }
.pub-panel-full .pub-year:first-child { margin-top: 12px; }
.year {
  display: flex; align-items: center; gap: 14px; margin: 0 0 4px;
  font-size: 1.05rem; font-weight: 700;
}
.year::after { content: ""; flex: 1; height: 1px; background: var(--line); }

.pubs { margin: 0; padding: 0; list-style: none; }
.pub { display: grid; grid-template-columns: 216px minmax(0, 1fr); gap: 24px; padding: 18px 0; }
.pub + .pub { border-top: 1px solid #f0f2f4; }
.pub-thumb {
  width: 100%; aspect-ratio: 3 / 2; padding: 6px;
  object-fit: contain; background: #fff;
  border: 1px solid var(--line); border-radius: 8px;
}
.pub-tags { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 7px; }
.pub-title { margin: 0 0 4px; font-size: 1.02rem; font-weight: 600; line-height: 1.4; letter-spacing: -0.005em; }
.pub-authors { margin: 0 0 5px; color: var(--muted); font-size: 0.92rem; line-height: 1.55; }
.pub-authors b { color: var(--text); font-weight: 600; }
.pub-venue {
  display: flex; flex-wrap: wrap; align-items: center; gap: 6px 10px;
  margin: 0 0 10px; font-size: 0.92rem; font-weight: 600;
}
.pub-note {
  padding: 3px 9px; border-radius: 999px;
  background: var(--note-soft); color: var(--note);
  font-size: 0.78rem; font-weight: 600; line-height: 1.35;
}
.pub-note a { color: inherit; text-decoration: underline; text-underline-offset: 2px; }
.pub-links { display: flex; flex-wrap: wrap; gap: 6px; margin: 0; }
.pub-links a {
  padding: 3px 11px; border: 1px solid var(--line); border-radius: 6px;
  color: var(--text); font-size: 0.8rem; font-weight: 500;
  transition: border-color 0.15s, color 0.15s;
}
.pub-links a:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }

/* Full tab: text-only entries, venue and links on one line */
.pub-panel-full .pub { display: block; padding: 14px 0; }
.pub-panel-full .pub-thumb { display: none; }
.pub-panel-full .pub-venue { display: inline-flex; margin: 0 10px 0 0; vertical-align: middle; }
.pub-panel-full .pub-links { display: inline-flex; vertical-align: middle; }

/* Service, awards, and other dated lists */

.service { display: grid; gap: 14px; margin: 0; }
.service > div { display: grid; grid-template-columns: 11rem minmax(0, 1fr); gap: 16px; }
.service dt { font-weight: 600; }
.service dd { margin: 0; color: var(--muted); }
.service dd span { display: block; }

.entries { display: grid; gap: 14px; margin: 0; padding: 0; list-style: none; }
.entries li { display: grid; grid-template-columns: var(--date-w, 5.25rem) minmax(0, 1fr); gap: 16px; }
.entries.ranges { --date-w: 10.5rem; }
.entries .date { padding-top: 2px; color: var(--muted); font-size: 0.86rem; font-weight: 500; font-variant-numeric: tabular-nums; white-space: nowrap; }
.entries .org { display: block; color: var(--muted); font-size: 0.92rem; }

.plain { margin: 0; padding-left: 1.2em; }
.plain li + li { margin-top: 6px; }

/* Footer */

.site-footer { margin-top: 24px; padding: 24px 0 40px; border-top: 1px solid var(--line); color: var(--faint); font-size: 0.85rem; }
.site-footer .container { display: flex; justify-content: space-between; gap: 16px; }
.site-footer a { color: var(--muted); }

/* 404 page */

.not-found { max-width: 480px; margin: 18vh auto; padding: 0 24px; text-align: center; }
.not-found .label { text-align: center; }
.not-found h1 { margin: 0 0 8px; font-size: 1.75rem; }
.not-found p { color: var(--muted); }

/* Responsive */

@media (max-width: 880px) {
  .hero { padding-top: 36px; }
  .hero > .container { grid-template-columns: minmax(0, 1fr); gap: 36px; }
  .profile { width: 100%; max-width: 480px; margin: 0 auto; }
}

@media (max-width: 640px) {
  .container { padding: 0 16px; }
  .brand { display: none; }
  .nav { width: 100%; justify-content: space-between; overflow-x: auto; scrollbar-width: none; }
  .nav a { padding: 6px 8px; font-size: 0.88rem; }
  .section { padding: 32px 0; }
  .section-title { font-size: 1.4rem; }
  .pub { grid-template-columns: minmax(0, 1fr); gap: 12px; }
  .pub-thumb { aspect-ratio: 2 / 1; }
  .news li { padding: 6px 14px; }
  .service > div, .entries li, .entries.ranges li { grid-template-columns: minmax(0, 1fr); gap: 2px; }
}

@media (max-width: 400px) {
  .site-header .container { padding: 0 10px; }
  .nav { gap: 0; }
  .nav a { padding: 6px 5px; font-size: 0.82rem; }
}