/* =========================================================
   Yanfei Chen — personal site
   Self-contained styles (no Bootstrap / jQuery runtime CSS)
   ========================================================= */

:root {
  --bg: #ffffff;
  --bg-soft: #f7f7f8;
  --text: #1f2328;
  --muted: #6b7280;
  --faint: #9aa0a6;
  --border: #e6e8eb;
  --accent: #b4232a;
  --accent-soft: rgba(180, 35, 42, 0.10);
  --link: #b4232a;
  --link-hover: #82171c;
  --badge-bg: #f0f1f3;
  --badge-text: #444b53;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.04), 0 4px 16px rgba(0, 0, 0, 0.05);
  --maxw: 980px;
}

html[data-theme="dark"] {
  --bg: #0e1116;
  --bg-soft: #161b22;
  --text: #e6e8eb;
  --muted: #9aa4ad;
  --faint: #6e7681;
  --border: #232a32;
  --accent: #ff7b72;
  --accent-soft: rgba(255, 123, 114, 0.12);
  --link: #ff8a82;
  --link-hover: #ffb1ab;
  --badge-bg: #1d242c;
  --badge-text: #c2cad2;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 6px 22px rgba(0, 0, 0, 0.45);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", Roboto,
    Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  transition: background-color 0.25s ease, color 0.25s ease;
}

a {
  color: var(--link);
  text-decoration: none;
  transition: color 0.15s ease;
}
a:hover { color: var(--link-hover); }

.in-text {
  border-bottom: 1px solid var(--accent-soft);
}
.in-text:hover { border-bottom-color: var(--link-hover); }

/* ---------- Layout ---------- */
.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 64px 28px 120px;
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 56px;
  align-items: start;
}

/* ---------- Sidebar ---------- */
.sidebar {
  position: sticky;
  top: 48px;
}

.profilepic {
  width: 160px;
  height: 160px;
  object-fit: cover;
  border-radius: 18px;
  box-shadow: var(--shadow);
  display: block;
}

.side-name {
  margin: 22px 0 2px;
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.side-role {
  margin: 0 0 18px;
  color: var(--muted);
  font-size: 0.95rem;
}

.links { display: flex; flex-direction: column; gap: 6px; }
.links a {
  color: var(--muted);
  font-size: 0.95rem;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  width: fit-content;
}
.links a:hover { color: var(--link); }
.links svg { width: 16px; height: 16px; flex: none; opacity: 0.85; }

/* ---------- Main column ---------- */
.main { min-width: 0; }

.hero-name {
  margin: 0;
  font-size: 2.4rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
}
.hero-sub {
  margin: 6px 0 28px;
  color: var(--muted);
  font-size: 1.05rem;
}

.about p { margin: 0 0 16px; }

section { scroll-margin-top: 32px; }

.header {
  margin: 52px 0 18px;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 14px;
}
.header::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--border);
}

/* ---------- Experience / Education / generic rows ---------- */
.entry {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 16px;
  padding: 7px 0;
}
.entry .when {
  color: var(--faint);
  font-size: 0.88rem;
  font-variant-numeric: tabular-nums;
}
.entry .what { font-size: 0.97rem; }
.entry .what .org { font-weight: 600; }
.entry .what .sub { color: var(--muted); }

/* ---------- Publications ---------- */
.pub-toggle {
  display: inline-flex;
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 3px;
  margin: 0 0 6px;
  background: var(--bg-soft);
}
.pub-toggle button {
  border: 0;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 0.85rem;
  padding: 5px 16px;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.15s ease;
}
.pub-toggle button[aria-pressed="true"] {
  background: var(--accent);
  color: #fff;
}
html[data-theme="dark"] .pub-toggle button[aria-pressed="true"] { color: #0e1116; }

#publications[data-view="selected"] .paper:not([data-selected="true"]) { display: none; }

.year-head {
  margin: 26px 0 8px;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--faint);
  font-variant-numeric: tabular-nums;
}

.paper {
  padding: 14px 0 14px 18px;
  border-left: 2px solid var(--border);
  margin: 4px 0;
  transition: border-color 0.15s ease;
}
.paper:hover { border-left-color: var(--accent); }

.papertitle {
  font-weight: 600;
  color: var(--text);
  font-size: 1.0rem;
}
.authors {
  display: block;
  margin: 3px 0;
  color: var(--muted);
  font-size: 0.92rem;
}
.thisauthor { color: var(--text); font-weight: 600; }
.noter { font-size: 0.8rem; color: var(--faint); }

.pub-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-top: 7px;
}

.badge {
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  padding: 2px 9px;
  border-radius: 999px;
  background: var(--badge-bg);
  color: var(--badge-text);
  white-space: nowrap;
}
.badge[data-venue="NeurIPS"] { background: #ede7f6; color: #5e35b1; }
.badge[data-venue="ICLR"]    { background: #e3f2fd; color: #1565c0; }
.badge[data-venue="ACL"]     { background: #fde8e8; color: #c0392b; }
.badge[data-venue="EMNLP"]   { background: #e0f2f1; color: #00796b; }
.badge[data-venue="EACL"]    { background: #fff3e0; color: #e65100; }
.badge[data-venue="COLM"]    { background: #e8f5e9; color: #2e7d32; }
.badge[data-venue="arXiv"]   { background: var(--badge-bg); color: var(--badge-text); }
html[data-theme="dark"] .badge[data-venue="NeurIPS"] { background: rgba(94,53,177,0.22); color: #c9b6f5; }
html[data-theme="dark"] .badge[data-venue="ICLR"]    { background: rgba(21,101,192,0.22); color: #9ec9f5; }
html[data-theme="dark"] .badge[data-venue="ACL"]     { background: rgba(192,57,43,0.22);  color: #f3a39b; }
html[data-theme="dark"] .badge[data-venue="EMNLP"]   { background: rgba(0,121,107,0.22);  color: #8fd6cd; }
html[data-theme="dark"] .badge[data-venue="EACL"]    { background: rgba(230,81,0,0.22);   color: #f5b483; }
html[data-theme="dark"] .badge[data-venue="COLM"]    { background: rgba(46,125,50,0.22);  color: #9bd6a0; }

.venue-full { color: var(--muted); font-size: 0.86rem; }

.tag {
  font-size: 0.84rem;
  color: var(--link);
  border: 1px solid var(--border);
  padding: 1px 9px;
  border-radius: 6px;
}
.tag:hover { border-color: var(--accent); background: var(--accent-soft); }

.scholar-note { margin-top: 22px; color: var(--muted); font-size: 0.92rem; }

/* ---------- Theme toggle ---------- */
.theme-toggle {
  position: fixed;
  top: 18px;
  right: 18px;
  z-index: 50;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-soft);
  color: var(--text);
  cursor: pointer;
  display: grid;
  place-items: center;
  box-shadow: var(--shadow);
  transition: transform 0.15s ease, background 0.2s ease;
}
.theme-toggle:hover { transform: scale(1.06); }
.theme-toggle svg { width: 18px; height: 18px; }
.theme-toggle .sun { display: none; }
html[data-theme="dark"] .theme-toggle .sun { display: block; }
html[data-theme="dark"] .theme-toggle .moon { display: none; }

/* ---------- Responsive ---------- */
@media (max-width: 820px) {
  .wrap {
    grid-template-columns: 1fr;
    gap: 8px;
    padding: 40px 22px 90px;
  }
  .sidebar {
    position: static;
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 0 22px;
    align-items: center;
    margin-bottom: 18px;
  }
  .profilepic { width: 104px; height: 104px; grid-row: span 2; }
  .side-name { margin-top: 0; }
  .links {
    grid-column: 1 / -1;
    flex-direction: row;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 14px;
  }
  .hero-name { font-size: 2rem; }
  .entry { grid-template-columns: 96px 1fr; gap: 12px; }
}

@media (max-width: 480px) {
  .entry { grid-template-columns: 1fr; gap: 0; }
  .entry .when { margin-bottom: 2px; }
}