:root {
  --bg: #F3F4F7;
  --surface: #FFFFFF;
  --ink: #161C33;
  --muted: #59617A;
  --rule: #D7DBE4;
  --indigo: #2B4790;
  --indigo-soft: #E3E8F4;
  --ember: #A6452D;
  color-scheme: light;
  box-sizing: border-box;
  padding-top: env(safe-area-inset-top, 0px);
  padding-bottom: env(safe-area-inset-bottom, 0px);
  --serif: "Newsreader", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --sans: "Hanken Grotesk", "Helvetica Neue", Arial, system-ui, sans-serif;
  --han: "Noto Serif SC", "Songti SC", "SimSun", serif;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0E1222; --surface: #151A2E; --ink: #E7EAF3; --muted: #9AA3BC;
    --rule: #283050; --indigo: #9AAFE8; --indigo-soft: #1D2544; --ember: #E39276;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0E1222; --surface: #151A2E; --ink: #E7EAF3; --muted: #9AA3BC;
  --rule: #283050; --indigo: #9AAFE8; --indigo-soft: #1D2544; --ember: #E39276;
  color-scheme: dark;
}
*, *::before, *::after { box-sizing: inherit; }
html { scroll-padding-top: calc(env(safe-area-inset-top, 0px) + 1rem); scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font-family: var(--serif); font-size: 1.1875rem; line-height: 1.6;
  font-optical-sizing: auto; -webkit-font-smoothing: antialiased;
}
a { color: var(--indigo); text-decoration-thickness: 1px; text-underline-offset: 0.18em; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--indigo); outline-offset: 3px; border-radius: 2px; }
img { max-width: 100%; }

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 clamp(1.25rem, 4vw, 2.5rem); }

/* Top bar */
.top { display: flex; justify-content: space-between; align-items: baseline; gap: 1rem; flex-wrap: wrap;
  padding-top: 1.5rem; padding-bottom: 1rem; font-family: var(--sans); font-size: 0.9375rem; }
.top .home { color: var(--ink); text-decoration: none; font-weight: 600; }
.top nav ul { list-style: none; display: flex; flex-wrap: wrap; gap: 0.25rem 1.5rem; margin: 0; padding: 0; }
.top nav a { color: var(--muted); text-decoration: none; }
.top nav a:hover { color: var(--ink); }

/* Hero */
.hero { padding-top: clamp(2.5rem, 8vw, 6rem); }
.name h1 {
  margin: 0; font-weight: 300; font-size: clamp(2.75rem, 9vw, 6.25rem);
  line-height: 0.88; letter-spacing: -0.035em; color: var(--ink);
}
.hanzi {
  display: block; margin-top: 0.9rem; font-family: var(--han); font-weight: 500;
  font-size: clamp(1.25rem, 3.4vw, 2.4rem); color: var(--indigo);
  line-height: 1; letter-spacing: 0.12em;
}
.lede { max-width: none; margin: 1.75rem 0 0; font-size: clamp(1.15rem, 2.1vw, 1.5rem); line-height: 1.4; }


/* Sections */
section { border-top: 1px solid var(--rule); padding: clamp(2.5rem, 6vw, 4.5rem) 0; }
.hero + section { margin-top: clamp(2.5rem, 6vw, 4rem); }
.grid { display: grid; grid-template-columns: minmax(0, 1fr); gap: 1.25rem 3rem; }
@media (min-width: 880px) {
  .grid { grid-template-columns: 13rem minmax(0, 1fr); }
  .grid > h2 { position: sticky; top: 1.5rem; align-self: start; }
}
h2 { margin: 0; font-weight: 400; font-size: clamp(1.75rem, 3vw, 2.125rem); line-height: 1.15; letter-spacing: -0.01em; }
h3 { margin: 0 0 0.5rem; font-weight: 500; font-size: 1.375rem; line-height: 1.3; }
.prose { max-width: 66ch; }
.prose p { margin: 0 0 1.1em; }
.prose p:last-child { margin-bottom: 0; }

/* About */
.about { display: grid; gap: 2.5rem; }
@media (min-width: 1040px) { .about { grid-template-columns: minmax(0, 1fr) 15rem; gap: 3.5rem; } }
.side { order: -1; display: grid; grid-template-columns: 8rem minmax(0, 1fr); gap: 1.5rem; align-items: start; }
.portrait { display: block; width: 100%; height: auto; aspect-ratio: 1; object-fit: cover; border-radius: 10px; background: var(--indigo-soft); }
@media (min-width: 640px) { .side { grid-template-columns: 11rem minmax(0, 1fr); } }
@media (min-width: 1040px) { .side { order: 0; grid-template-columns: minmax(0, 1fr); gap: 1.75rem; } }
.facts { font-family: var(--sans); font-size: 0.9375rem; line-height: 1.5; margin: 0; }
.facts dt { color: var(--muted); margin-top: 1.1rem; }
.facts dt:first-child { margin-top: 0; }
.facts dd { margin: 0.15rem 0 0; }
.facts .links { display: flex; flex-wrap: wrap; gap: 0.35rem 1rem; }

/* Research */
.topics { display: grid; gap: 2.75rem; }
.topic p { margin: 0 0 0.9em; max-width: 66ch; }
.topic p:last-child { margin-bottom: 0; }
.figure { margin: 1.5rem 0 1.75rem; max-width: 66ch; }
.figure-square { max-width: 34rem; }
.figure img { display: block; width: 100%; height: auto; background: #fff; border: 1px solid var(--rule); border-radius: 8px; padding: 0.75rem; }
.figure figcaption { font-family: var(--sans); font-size: 0.875rem; line-height: 1.5; color: var(--muted); margin-top: 0.6rem; }
.err { display: inline-flex; flex-direction: column; vertical-align: -0.45em; font-size: 0.68em; line-height: 1.05; margin-left: 0.1em; }
.err sup, .err sub { vertical-align: baseline; font-size: 1em; line-height: 1.05; }

/* Publications */
.pub-controls { display: inline-flex; border: 1px solid var(--rule); border-radius: 999px; padding: 3px; margin-bottom: 2rem; background: var(--surface); font-family: var(--sans); }
.pub-controls button {
  font: inherit; font-size: 0.9375rem; border: 0; background: transparent; color: var(--muted);
  padding: 0.4rem 1rem; border-radius: 999px; cursor: pointer;
}
.pub-controls button[aria-pressed="true"] { background: var(--indigo-soft); color: var(--ink); font-weight: 500; }
.year-group { display: grid; grid-template-columns: 3.75rem minmax(0, 1fr); gap: 0 1.25rem; padding: 1.25rem 0; border-top: 1px solid var(--rule); }
.year-group:first-of-type { border-top: 0; padding-top: 0; }
.year { font-family: var(--sans); font-size: 0.9375rem; color: var(--muted); padding-top: 0.25rem; font-variant-numeric: tabular-nums; }
.papers { list-style: none; margin: 0; padding: 0; display: grid; gap: 1.25rem; }
.paper .title { font-size: 1.1875rem; line-height: 1.4; }
.paper .title a { color: var(--ink); text-decoration-color: var(--rule); }
.paper .title a:hover { color: var(--indigo); text-decoration-color: currentColor; }
.paper .meta { font-family: var(--sans); font-size: 0.875rem; color: var(--muted); margin-top: 0.2rem; line-height: 1.5; }
.paper .meta b { color: var(--ink); font-weight: 600; }
.paper .series { display: block; font-family: var(--sans); font-size: 0.8125rem; color: var(--muted); margin-bottom: 0.1rem; }

/* Talks */
.talk-year { font-family: var(--sans); font-size: 0.9375rem; color: var(--muted); margin: 1.75rem 0 0.5rem; font-weight: 500; }
.talk-year:first-child { margin-top: 0; }
.talks { list-style: none; margin: 0; padding: 0; }
.talks li { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 0.25rem 1rem; padding: 0.6rem 0; border-top: 1px solid var(--rule); align-items: baseline; }
.talks .what { line-height: 1.4; }
.talks .where { display: block; font-family: var(--sans); font-size: 0.875rem; color: var(--muted); }
.talks .kind { font-family: var(--sans); font-size: 0.8125rem; color: var(--indigo); white-space: nowrap; }
.more-btn {
  margin-top: 1.5rem; font-family: var(--sans); font-size: 0.9375rem; color: var(--indigo);
  background: none; border: 1px solid var(--rule); border-radius: 999px; padding: 0.5rem 1.1rem; cursor: pointer;
}
.more-btn:hover { border-color: var(--indigo); }

/* CV */
.cv-row { display: flex; flex-wrap: wrap; align-items: center; gap: 1rem 1.5rem; }
.button {
  display: inline-block; font-family: var(--sans); font-size: 1rem; font-weight: 500;
  background: var(--indigo); color: var(--bg); text-decoration: none; padding: 0.7rem 1.4rem; border-radius: 6px;
}
.button:hover { filter: brightness(1.1); }

/* Footer */
footer { border-top: 1px solid var(--rule); padding: 2.5rem 0 3rem; font-family: var(--sans); font-size: 0.875rem; color: var(--muted); }
footer .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 1rem 2rem; }
footer address { font-style: normal; line-height: 1.6; }