:root {
  --bg: #fbfaf7;
  --surface: #ffffff;
  --text: #1f2328;
  --muted: #5f6670;
  --line: #e4e1da;
  --accent: #a51c30;        /* Harvard crimson */
  --accent-soft: #f6e8ea;
  --tag: #eef1f4;
  --ongoing: #1f7a4d;
  --ongoing-soft: #e3f3ea;
  --serif: "Newsreader", Georgia, serif;
  --sans: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15171a;
    --surface: #1c1f23;
    --text: #e6e6e3;
    --muted: #a0a6ad;
    --line: #2d3137;
    --accent: #e0707f;
    --accent-soft: #3a2328;
    --tag: #262a30;
    --ongoing: #6fd3a0;
    --ongoing-soft: #1d3329;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 72px; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
}

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

.wrap { max-width: 920px; margin: 0 auto; padding: 0 20px; }

/* ---------- nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.nav .wrap { display: flex; align-items: center; justify-content: space-between; height: 56px; gap: 16px; }
.nav .brand { font-family: var(--serif); font-weight: 600; font-size: 1.1rem; color: var(--text); white-space: nowrap; }
.nav ul { list-style: none; display: flex; gap: 18px; margin: 0; padding: 0; overflow-x: auto; }
.nav ul a { color: var(--muted); font-size: 0.9rem; white-space: nowrap; }
.nav ul a:hover { color: var(--accent); text-decoration: none; }

/* ---------- sections ---------- */
section { padding: 44px 0 8px; }
h1, h2, h3 { font-family: var(--serif); font-weight: 600; line-height: 1.25; }
h2 {
  font-size: 1.85rem; font-weight: 500; margin: 0 0 20px;
  padding-bottom: 8px; border-bottom: 1px solid var(--line);
}
h3 { margin: 32px 0 12px; color: var(--accent); font-family: var(--mono); font-weight: 500; text-transform: uppercase; letter-spacing: 0.08em; font-size: 0.78rem; }
.lede { color: var(--muted); margin-top: -10px; margin-bottom: 20px; font-size: 0.95rem; }

/* ---------- hero ---------- */
.hero { display: grid; grid-template-columns: 260px 1fr; gap: 40px; padding-top: 48px; align-items: start; }

.sidebar img {
  display: block; width: 100%; aspect-ratio: 4 / 5; object-fit: cover; object-position: 50% 55%;
  border-radius: 12px; border: 1px solid var(--line);
}
.hero h1 { font-size: 2.7rem; font-weight: 500; letter-spacing: -0.01em; margin: 0 0 4px; }
.hero .role { color: var(--muted); margin: 0 0 16px; }
.hero p { margin: 0 0 12px; }
.links { display: flex; flex-direction: column; gap: 2px; margin-top: 16px; font-size: 0.88rem; }
.links a, .links > span {
  display: flex; align-items: center; gap: 10px; padding: 5px 4px;
  color: var(--text); border-radius: 6px; overflow-wrap: anywhere;
}
.links > span { color: var(--muted); }
.links a span { display: inline; padding: 0; color: inherit; }
.links .short { display: none; }
.links i { width: 16px; text-align: center; color: var(--accent); }
.links a:hover { background: var(--accent-soft); color: var(--accent); text-decoration: none; }

.interests { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 14px; }
.interests span { background: var(--accent-soft); color: var(--accent); font-size: 0.8rem; padding: 2px 10px; border-radius: 999px; }

/* ---------- news ---------- */
.news { list-style: none; margin: 0; padding: 0; }
.news li { display: grid; grid-template-columns: 92px 1fr; gap: 12px; padding: 6px 0; font-size: 0.95rem; }
.news .date { color: var(--muted); font-family: var(--mono); font-size: 0.8rem; padding-top: 1px; }

/* ---------- projects ---------- */
.projects { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: 10px;
  padding: 18px 20px; display: flex; flex-direction: column;
}
.card h4 { font-family: var(--serif); font-size: 1.22rem; font-weight: 600; margin: 6px 0 6px; line-height: 1.3; }
.card p { margin: 0 0 10px; font-size: 0.92rem; color: var(--text); }
.card .meta { font-size: 0.84rem; color: var(--muted); margin-bottom: 10px; display: flex; flex-direction: column; }
.card .foot { margin-top: auto; display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }
.status { font-family: var(--mono); font-size: 0.7rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; padding: 2px 8px; border-radius: 4px; align-self: flex-start; }
.status.ongoing { color: var(--ongoing); background: var(--ongoing-soft); }
.status.done { color: var(--muted); background: var(--tag); }
.tag { font-size: 0.75rem; background: var(--tag); color: var(--muted); padding: 1px 8px; border-radius: 4px; }


/* ---------- publications ---------- */
.pubs { list-style: none; margin: 0; padding: 0; }
.pub { display: grid; grid-template-columns: 112px 1fr; gap: 16px; padding: 12px 0; border-bottom: 1px dashed var(--line); }
.pub:last-child { border-bottom: none; }
.venue {
  align-self: start; text-align: center; font-family: var(--mono); font-size: 0.72rem; font-weight: 500;
  padding: 3px 6px; border-radius: 4px; background: var(--accent); color: #fff;
}
.venue.ws { background: var(--tag); color: var(--muted); }
.pub .title { font-weight: 600; display: block; }
.pub .authors { font-size: 0.9rem; color: var(--muted); display: block; }
.pub .authors b { color: var(--text); }
.pub .where { font-size: 0.9rem; font-style: italic; display: block; }
.pub .btns { margin-top: 4px; display: flex; flex-wrap: wrap; gap: 6px; }
.pub .btns a, .card .btn {
  font-size: 0.75rem; padding: 1px 8px; border: 1px solid var(--accent); border-radius: 4px;
}
.pub .btns a:hover, .card .btn:hover { background: var(--accent); color: #fff; text-decoration: none; }
.note { font-size: 0.85rem; color: var(--muted); }

/* ---------- timeline lists (experience, awards, service) ---------- */
.rows { list-style: none; margin: 0; padding: 0; }
.rows li { display: grid; grid-template-columns: 1fr auto; gap: 4px 16px; padding: 10px 0; border-bottom: 1px solid var(--line); }
.rows li:last-child { border-bottom: none; }
.rows .what { font-weight: 600; }
.rows .when { color: var(--muted); font-family: var(--mono); font-size: 0.78rem; white-space: nowrap; font-variant-numeric: tabular-nums; }
.rows .detail { grid-column: 1 / -1; font-size: 0.92rem; color: var(--muted); }
.rows .detail b { color: var(--text); font-weight: 500; }

/* ---------- experience entries ---------- */
.entries { list-style: none; margin: 0; padding: 0; }
.entry { padding: 14px 0; border-bottom: 1px solid var(--line); }
.entry:last-child { border-bottom: none; }
.entry .head { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; }
.entry .org { font-weight: 600; font-size: 1.02rem; }
.entry .org a { color: var(--text); border-bottom: 1px solid var(--line); }
.entry .org a:hover { color: var(--accent); border-color: var(--accent); text-decoration: none; }
.entry .when { color: var(--muted); font-family: var(--mono); font-size: 0.78rem; white-space: nowrap; }
.entry .role { font-style: italic; }
.entry .mentor { font-size: 0.9rem; color: var(--muted); }
.entry .did { margin: 6px 0 0; padding-left: 18px; font-size: 0.92rem; }
.entry .did li { margin: 2px 0; }

.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 0 32px; }

footer { margin-top: 56px; line-height: 1.6; padding: 24px 0 40px; border-top: 1px solid var(--line); color: var(--muted); font-size: 0.85rem; }

/* ---------- responsive ---------- */
@media (max-width: 760px) {
  .nav ul { display: none; }
  .hero { grid-template-columns: 1fr; gap: 20px; padding-top: 28px; }
  .sidebar { position: static; display: grid; grid-template-columns: 140px 1fr; gap: 16px; align-items: start; }
  .links { margin-top: 0; }
  .links .full { display: none; }
  .links .short { display: inline; }
  .hero h1 { font-size: 1.9rem; }
  .projects, /* ---------- experience entries ---------- */
.entries { list-style: none; margin: 0; padding: 0; }
.entry { padding: 14px 0; border-bottom: 1px solid var(--line); }
.entry:last-child { border-bottom: none; }
.entry .head { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; }
.entry .org { font-weight: 600; font-size: 1.02rem; }
.entry .org a { color: var(--text); border-bottom: 1px solid var(--line); }
.entry .org a:hover { color: var(--accent); border-color: var(--accent); text-decoration: none; }
.entry .when { color: var(--muted); font-family: var(--mono); font-size: 0.78rem; white-space: nowrap; }
.entry .role { font-style: italic; }
.entry .mentor { font-size: 0.9rem; color: var(--muted); }
.entry .did { margin: 6px 0 0; padding-left: 18px; font-size: 0.92rem; }
.entry .did li { margin: 2px 0; }

.two-col { grid-template-columns: 1fr; }
  .pub { grid-template-columns: 1fr; gap: 6px; }
  .venue { justify-self: start; }
  .news li { grid-template-columns: 1fr; gap: 0; }
  .rows li { grid-template-columns: 1fr; }
  .entry .head { flex-direction: column; gap: 0; }
}

/* ---------- collaboration callout ---------- */
.callout {
  display: flex; gap: 14px; align-items: flex-start;
  margin-top: 20px; padding: 16px 20px;
  background: var(--accent-soft); border-left: 3px solid var(--accent); border-radius: 6px;
}
.callout i { color: var(--accent); font-size: 1.2rem; margin-top: 4px; }
.callout p { margin: 0; font-size: 0.95rem; }

/* ---------- project filters ---------- */
.filters { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.filters button {
  font: inherit; font-size: 0.85rem; cursor: pointer;
  padding: 4px 14px; border-radius: 999px;
  border: 1px solid var(--line); background: var(--surface); color: var(--muted);
}
.filters button:hover { border-color: var(--accent); color: var(--accent); }
.filters button[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: #fff; }
.card[hidden] { display: none; }

/* ---------- skills ---------- */
.skills { display: grid; grid-template-columns: 1fr 1fr; gap: 4px 32px; }
.skill-group h3 { margin-top: 8px; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chips span {
  font-size: 0.84rem; padding: 3px 10px; border-radius: 6px;
  background: var(--surface); border: 1px solid var(--line);
}
@media (max-width: 760px) { .skills { grid-template-columns: 1fr; } }