/* ---------- Tokens ---------- */
:root {
  --bg: #fbfbf9;
  --surface: #f2f2ee;
  --text: #1b1d21;
  --muted: #565c66;
  --faint: #868c95;
  --border: #e4e3de;
  --accent: #1d5a96;
  --accent-hover: #15467a;
  --accent-soft: #e7eff8;
  --header-bg: rgba(251, 251, 249, 0.85);

  --font-sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --maxw: 780px;
  --radius: 10px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #121418;
    --surface: #1b1e23;
    --text: #e6e6e3;
    --muted: #a3a9b2;
    --faint: #7b818a;
    --border: #2a2e35;
    --accent: #84b6ea;
    --accent-hover: #a8cbf0;
    --accent-soft: #1a2838;
    --header-bg: rgba(18, 20, 24, 0.85);
  }
}

:root[data-theme="dark"] {
  --bg: #121418;
  --surface: #1b1e23;
  --text: #e6e6e3;
  --muted: #a3a9b2;
  --faint: #7b818a;
  --border: #2a2e35;
  --accent: #84b6ea;
  --accent-hover: #a8cbf0;
  --accent-soft: #1a2838;
  --header-bg: rgba(18, 20, 24, 0.85);
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

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

a {
  color: var(--accent);
  text-decoration: none;
  text-underline-offset: 3px;
}
a:hover { color: var(--accent-hover); text-decoration: underline; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

p { margin: 0 0 1em; }

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
}

.skip-link {
  position: absolute;
  left: -9999px;
}
.skip-link:focus {
  left: 16px;
  top: 12px;
  z-index: 20;
  background: var(--bg);
  padding: 6px 10px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--header-bg);
  -webkit-backdrop-filter: saturate(160%) blur(10px);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 24px;
  height: 58px;
}

.brand {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.15rem;
  color: var(--text);
  white-space: nowrap;
}
.brand:hover { color: var(--text); text-decoration: none; }

.site-nav {
  display: flex;
  gap: 22px;
  margin-left: auto;
  font-size: 0.92rem;
}
.site-nav a { color: var(--muted); }
.site-nav a:hover { color: var(--text); text-decoration: none; }

.theme-toggle {
  display: inline-grid;
  place-items: center;
  width: 34px;
  height: 34px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
}
.theme-toggle:hover { color: var(--text); border-color: var(--faint); }
.theme-toggle svg {
  width: 17px;
  height: 17px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.theme-toggle .icon-sun { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-sun { display: block; }
:root[data-theme="dark"] .theme-toggle .icon-moon { display: none; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .icon-sun { display: block; }
  :root:not([data-theme="light"]) .theme-toggle .icon-moon { display: none; }
}

/* ---------- Hero ---------- */
.hero {
  display: grid;
  grid-template-columns: 176px 1fr;
  gap: 40px;
  align-items: center;
  padding: 64px 0 36px;
}

.avatar {
  display: block;
  width: 176px;
  height: 176px;
  border-radius: 50%;
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--surface);
}
/* Zoom in on the face: the source photo is a wide 1440px square. */
.avatar img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: scale(1.5);
  transform-origin: 65% 74%;
}

h1 {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 2.5rem;
  line-height: 1.15;
  letter-spacing: -0.01em;
  margin: 0 0 10px;
}

.role {
  margin: 0;
  color: var(--muted);
  font-size: 1.02rem;
}
.role a { color: inherit; }
.role a:hover { color: var(--accent); }

.contact {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 0;
  margin: 20px 0 0;
}
.contact a {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text);
  font-size: 0.875rem;
  font-weight: 500;
  transition: border-color 0.15s, color 0.15s, background-color 0.15s;
}
.contact a:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
  text-decoration: none;
}
.contact svg {
  width: 15px;
  height: 15px;
  fill: currentColor;
  flex: none;
}
.contact svg.stroke {
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* ---------- Bio ---------- */
.bio {
  font-size: 1.02rem;
}
.bio strong { font-weight: 600; }

.tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 0;
  margin: 18px 0 0;
}
.tags li {
  padding: 3px 11px;
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  font-size: 0.84rem;
}

/* ---------- Sections ---------- */
main section[id] { scroll-margin-top: 76px; }

h2 {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.55rem;
  letter-spacing: -0.005em;
  margin: 60px 0 22px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}

h3 {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.45;
  margin: 0;
}

/* ---------- News ---------- */
.news {
  list-style: none;
  padding: 0;
  margin: 0;
}
.news li {
  display: grid;
  grid-template-columns: 84px 1fr;
  gap: 16px;
  padding: 7px 0;
}
.news time {
  color: var(--faint);
  font-size: 0.875rem;
  font-variant-numeric: tabular-nums;
  padding-top: 2px;
  white-space: nowrap;
}
.news p { margin: 0; }

/* ---------- Publications ---------- */
.pub {
  display: grid;
  grid-template-columns: 112px 1fr;
  gap: 20px;
  padding: 18px 0;
  scroll-margin-top: 76px;
}
.pub + .pub { border-top: 1px solid var(--border); }
.pub-body { min-width: 0; }

.badge {
  display: inline-block;
  padding: 3px 9px;
  border-radius: 6px;
  border: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  white-space: nowrap;
}
.badge-main {
  border-color: transparent;
  background: var(--accent-soft);
  color: var(--accent);
}

.pub h3 { font-size: 1.04rem; margin-bottom: 4px; }
.pub h3 a { color: var(--text); }
.pub h3 a:hover { color: var(--accent); text-decoration: none; }

.authors { margin: 0; color: var(--muted); font-size: 0.94rem; }
.authors .me { color: var(--text); font-weight: 600; }
.authors sup { font-size: 0.7em; }

.venue { margin: 2px 0 0; color: var(--muted); font-size: 0.94rem; font-style: italic; }

.tldr { margin: 8px 0 0; font-size: 0.94rem; }

.links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 12px;
}
.links a,
.links button {
  display: inline-block;
  padding: 2px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
  font: 500 0.8rem/1.6 var(--font-sans);
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}
.links a:hover,
.links button:hover,
.links button[aria-expanded="true"] {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}

.bibtex {
  position: relative;
  margin-top: 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
}
.bibtex pre {
  margin: 0;
  padding: 14px 16px;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  font: 0.78rem/1.55 var(--font-mono);
  color: var(--text);
}
.bib-copy {
  position: absolute;
  top: 8px;
  right: 8px;
  padding: 2px 9px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--muted);
  font: 500 0.75rem/1.6 var(--font-sans);
  cursor: pointer;
}
.bib-copy:hover { color: var(--accent); border-color: var(--accent); }

.footnote { margin-top: 10px; color: var(--faint); font-size: 0.85rem; }

/* ---------- Experience / Education ---------- */
.entry { padding: 12px 0; }
.entry + .entry { border-top: 1px solid var(--border); padding-top: 18px; }

.entry-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
}
.org { margin: 2px 0 0; color: var(--muted); font-size: 0.94rem; }
.dates {
  color: var(--faint);
  font-size: 0.875rem;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.entry ul {
  margin: 8px 0 0;
  padding-left: 18px;
  font-size: 0.95rem;
}
.entry li { margin: 3px 0; }
.entry li::marker { color: var(--faint); }

/* ---------- Service ---------- */
.service {
  display: grid;
  grid-template-columns: 84px 1fr;
  gap: 6px 16px;
  margin: 0;
}
.service dt { color: var(--faint); font-size: 0.875rem; padding-top: 2px; }
.service dd { margin: 0; }

/* ---------- Footer ---------- */
.site-footer {
  margin-top: 72px;
  border-top: 1px solid var(--border);
  padding: 26px 0 36px;
  color: var(--faint);
  font-size: 0.85rem;
}
.site-footer p { margin: 0; }

/* ---------- Responsive ---------- */
@media (max-width: 720px) {
  .site-nav { display: none; }
  .theme-toggle { margin-left: auto; }

  .hero {
    grid-template-columns: 1fr;
    justify-items: center;
    text-align: center;
    gap: 22px;
    padding-top: 40px;
  }
  .avatar { width: 136px; height: 136px; }
  h1 { font-size: 2.1rem; }
  .contact { justify-content: center; }

  h2 { margin-top: 48px; }

  .pub { grid-template-columns: 1fr; gap: 8px; }

  .entry-head { flex-direction: column; gap: 2px; }
}

@media (max-width: 420px) {
  .news li { grid-template-columns: 1fr; gap: 0; }
}