/* Self-hosted fonts (Latin subset), so the page never waits on a third-party font host. */
@font-face { font-family: "Source Serif 4"; font-style: normal; font-weight: 500 600; font-display: swap; src: url("fonts/source-serif-4.woff2") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2190-2199, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Source Serif 4"; font-style: italic; font-weight: 500; font-display: swap; src: url("fonts/source-serif-4-italic.woff2") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2190-2199, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Source Sans 3"; font-style: normal; font-weight: 200 900; font-display: swap; src: url("fonts/source-sans-3.woff2") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2190-2199, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Source Sans 3"; font-style: italic; font-weight: 200 900; font-display: swap; src: url("fonts/source-sans-3-italic.woff2") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2190-2199, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Source Code Pro"; font-style: normal; font-weight: 200 900; font-display: swap; src: url("fonts/source-code-pro.woff2") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2190-2199, U+2212, U+2215, U+FEFF, U+FFFD; }

/* Layout: one 1120px frame. A two-column hero, then three research questions side by side,
   then highlight rows that pair a fixed 16:9 figure frame with text, then dense index lists. */
:root {
  --paper: #f6f8f9;
  --surface: #ffffff;
  --ink: #1e262c;
  --muted: #59656e;
  --rule: #d6dde2;
  --navy: #24475d;
  --navy-soft: #e3ebf0;
  --signal: #9a5f1c;
  --figure-bg: #ffffff;
  --video-bg: #000000;
  --spec-bg: #f6f8f9;
  --spec-wash: rgba(36, 71, 93, 0.08);
  --spec-lt: block;
  --spec-dk: none;

  --display: "Source Serif 4", "Source Serif Pro", Georgia, "Times New Roman", serif;
  --body: "Source Sans 3", "Source Sans Pro", -apple-system, "Segoe UI", system-ui, sans-serif;
  --mono: "Source Code Pro", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;

  --s-xs: 0.8125rem;
  --s-sm: 0.9375rem;
  --s-md: 1.0625rem;
  --s-lg: 1.3125rem;
  --s-xl: 1.75rem;
  --s-2xl: clamp(2.25rem, 1.6rem + 2.6vw, 3.25rem);

  --frame: 1120px;
  --read: 44rem;
  --gutter: clamp(16px, 4vw, 40px);
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0f1418;
    --surface: #151c21;
    --ink: #e3e9ed;
    --muted: #9aa8b2;
    --rule: #28333b;
    --navy: #94bcd4;
    --navy-soft: #1b2a34;
    --signal: #e8a95e;
    --figure-bg: #f3f5f6;
    --spec-bg: #0b141c;
    --spec-wash: rgba(240, 178, 100, 0.12);
    --spec-lt: none;
    --spec-dk: block;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #0f1418;
  --surface: #151c21;
  --ink: #e3e9ed;
  --muted: #9aa8b2;
  --rule: #28333b;
  --navy: #94bcd4;
  --navy-soft: #1b2a34;
  --signal: #e8a95e;
  --figure-bg: #f3f5f6;
  --spec-bg: #0b141c;
  --spec-wash: rgba(240, 178, 100, 0.12);
  --spec-lt: none;
  --spec-dk: block;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 4.5rem; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  padding-inline: var(--gutter);
  padding-block: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body);
  font-size: var(--s-md);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
main, .masthead, .foot { max-width: var(--frame); margin-inline: auto; }
img, video { max-width: 100%; display: block; }
a { color: var(--navy); text-decoration-thickness: 1px; text-underline-offset: 0.18em; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--signal); outline-offset: 3px; border-radius: 3px; }
h1, h2, h3 { font-family: var(--display); font-weight: 600; text-wrap: balance; margin: 0; }
p { margin: 0; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip { position: absolute; left: -999px; top: 0; }
.skip:focus { left: var(--gutter); top: 8px; background: var(--surface); padding: 6px 10px; z-index: 20; }

/* Masthead */
.masthead {
  position: sticky;
  top: env(safe-area-inset-top, 0px);
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding-block: 0.85rem;
  background: var(--paper);
  border-bottom: 1px solid var(--rule);
  box-shadow: 0 0 0 100vmax var(--paper);
  clip-path: inset(0 -100vmax);
}
.brand { font-family: var(--display); font-weight: 600; font-size: var(--s-lg); color: var(--ink); text-decoration: none; white-space: nowrap; }
.nav { display: flex; gap: 1.35rem; margin-left: auto; overflow-x: auto; scrollbar-width: none; min-width: 0; }
.nav::-webkit-scrollbar { display: none; }
.nav a { color: var(--muted); text-decoration: none; font-size: var(--s-sm); white-space: nowrap; }
.nav a:hover { color: var(--ink); }
.theme-toggle {
  flex: none; display: grid; place-items: center; width: 34px; height: 34px;
  border: 1px solid var(--rule); border-radius: 50%; background: var(--surface); color: var(--ink); cursor: pointer;
}
.theme-toggle:hover { border-color: var(--navy); }

/* Hero */
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(180px, 260px);
  gap: clamp(1.5rem, 5vw, 4.5rem);
  align-items: center;
  padding-block: clamp(2.5rem, 7vw, 4.75rem) clamp(1.5rem, 4vw, 2.5rem);
}
.hero-text { min-width: 0; display: grid; gap: 1.15rem; }
.name { font-size: var(--s-2xl); line-height: 1.05; letter-spacing: -0.012em; color: var(--navy); }
.name-zh { font-family: var(--body); font-weight: 400; font-size: 0.42em; color: var(--muted); letter-spacing: 0.08em; margin-left: 0.35em; vertical-align: 0.35em; }
.thesis { font-family: var(--display); font-weight: 500; font-style: italic; font-size: clamp(1.4rem, 1.15rem + 1vw, 1.9rem); line-height: 1.25; color: var(--ink); }
.lede { max-width: var(--read); color: var(--muted); }
.actions { display: flex; flex-wrap: wrap; gap: 0.6rem; margin-top: 0.25rem; }
.btn {
  display: inline-flex; align-items: center; gap: 0.4rem;
  padding: 0.5rem 0.95rem; border: 1px solid var(--rule); border-radius: 999px;
  background: var(--surface); color: var(--ink); font: inherit; font-size: var(--s-sm); font-weight: 600;
  text-decoration: none; cursor: pointer;
}
.btn:hover { border-color: var(--navy); color: var(--navy); }
.btn-primary { background: var(--navy); border-color: var(--navy); color: var(--paper); }
.btn-primary:hover { color: var(--paper); filter: brightness(1.08); }
.btn-small { padding: 0.3rem 0.75rem; font-size: var(--s-xs); }
.portrait { margin: 0; justify-self: end; width: 100%; max-width: 260px; }
.portrait img { width: 100%; height: auto; aspect-ratio: 1; object-fit: cover; border-radius: 50%; }

/* Chips: demo controls and filters */
.chips { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.chip {
  display: inline-flex; align-items: center; gap: 0.45rem;
  padding: 0.35rem 0.8rem 0.35rem 0.6rem; border: 1px solid var(--rule); border-radius: 999px;
  background: var(--surface); color: var(--ink); font: inherit; font-size: var(--s-xs); font-weight: 600;
  text-decoration: none; cursor: pointer; line-height: 1.3;
}
.chip:hover { border-color: var(--navy); color: var(--navy); }
.chip[aria-pressed="true"] { border-color: var(--navy); background: var(--navy-soft); color: var(--navy); }
.chip .glyph { display: inline-grid; place-items: center; width: 1.1rem; height: 1.1rem; border-radius: 50%; background: var(--navy); color: var(--paper); }
.chip .glyph svg { width: 8px; height: 8px; }
.chip .dur { font-family: var(--mono); font-weight: 400; color: var(--muted); font-variant-numeric: tabular-nums; }

/* Generic blocks */
.block { padding-block: clamp(2.25rem, 5.5vw, 3.75rem) 0; }
.block-tight { padding-top: clamp(1rem, 3vw, 1.75rem); }
.block-head { display: grid; gap: 0.5rem; margin-bottom: 1.4rem; max-width: var(--read); }
.block-head h2 { font-size: var(--s-xl); color: var(--ink); }
.block-head p { color: var(--muted); font-size: var(--s-sm); }
.kicker { font-family: var(--mono); font-weight: 500; font-size: var(--s-xs); letter-spacing: 0.09em; text-transform: uppercase; color: var(--muted); margin-bottom: 0.9rem; }

/* Research themes: one row per direction, title and keywords on the left */
.themes { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--rule); }
.theme { display: grid; grid-template-columns: minmax(0, 17rem) minmax(0, 1fr); gap: 0.75rem clamp(1.5rem, 4vw, 3rem); padding-block: 1.4rem; border-bottom: 1px solid var(--rule); }
.theme-head { display: grid; gap: 0.4rem; align-content: start; }
.theme h3 { font-size: var(--s-lg); line-height: 1.3; color: var(--ink); }
.theme-keys { font-size: var(--s-xs); line-height: 1.5; color: var(--signal); }
.theme-body { display: grid; gap: 0.75rem; min-width: 0; }
.theme-body > p { font-size: var(--s-sm); color: var(--muted); max-width: var(--read); }
.theme-works { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 0.45rem; }
.theme-works li { display: inline-flex; align-items: baseline; gap: 0.45rem; padding: 0.25rem 0.7rem; border: 1px solid var(--rule); border-radius: 999px; background: var(--surface); font-size: var(--s-sm); }
.theme-works a { font-weight: 600; text-decoration: none; }
.theme-works a:hover { text-decoration: underline; }
.theme-works span { font-family: var(--mono); font-size: 0.75rem; color: var(--muted); white-space: nowrap; }

/* News */
.news-list { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--rule); }
.news-list li { display: grid; grid-template-columns: 3.5rem 11rem minmax(0, 1fr); gap: 1rem; padding-block: 0.6rem; border-bottom: 1px solid var(--rule); font-size: var(--s-sm); }
.news-list .y { font-family: var(--mono); color: var(--muted); font-variant-numeric: tabular-nums; }
.news-list .v { font-weight: 600; color: var(--ink); }
.news-more { margin-top: 0.6rem; }
.news-more summary { cursor: pointer; color: var(--navy); font-size: var(--s-sm); width: fit-content; }
.news-more[open] summary { margin-bottom: 0.6rem; }

/* Research highlights */
.features { display: grid; border-top: 1px solid var(--rule); }
.feature { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr); gap: clamp(1.25rem, 4vw, 3rem); padding-block: 2rem; border-bottom: 1px solid var(--rule); align-items: start; }
.feature-media { min-width: 0; display: grid; gap: 0.75rem; }
.frame { aspect-ratio: 16 / 9; max-width: 100%; background: var(--figure-bg); border: 1px solid var(--rule); border-radius: 10px; padding: 0.75rem; overflow: hidden; }
.frame img { width: 100%; height: 100%; object-fit: contain; }
.frame.is-video { padding: 0; background: var(--video-bg); }
.frame video { width: 100%; height: 100%; object-fit: contain; background: var(--video-bg); }
.demo { display: grid; gap: 0.55rem; }
.spec-wrap { display: grid; grid-template-columns: 2rem minmax(0, 1fr); gap: 0.35rem; }
.axis { position: relative; font-family: var(--mono); font-size: 0.6875rem; color: var(--muted); }
.axis span { position: absolute; right: 0; transform: translateY(50%); line-height: 1; }
.spec {
  position: relative; display: block; width: 100%; padding: 0; margin: 0;
  aspect-ratio: 6 / 1; border: 1px solid var(--rule); border-radius: 6px;
  background: var(--spec-bg); cursor: pointer; overflow: hidden;
}
.spec img { width: 100%; height: 100%; object-fit: fill; }
.spec img.lt { display: var(--spec-lt); }
.spec img.dk { display: var(--spec-dk); }
.spec .playhead { position: absolute; top: 0; bottom: 0; left: 0; width: 2px; background: var(--signal); opacity: 0; }
.spec.playing .playhead { opacity: 1; }
.spec .played { position: absolute; inset: 0 auto 0 0; width: 0; background: var(--spec-wash); }
.demo-caption { font-size: var(--s-xs); color: var(--muted); line-height: 1.5; }
.feature-text { min-width: 0; display: grid; gap: 0.8rem; align-content: start; }
.feature-meta { display: flex; flex-wrap: wrap; gap: 0.4rem 0.8rem; align-items: baseline; font-family: var(--mono); font-size: var(--s-xs); letter-spacing: 0.04em; color: var(--muted); }
.venue { color: var(--navy); font-weight: 500; }
.feature h3 { font-size: var(--s-xl); color: var(--ink); }
.feature .what { font-family: var(--display); font-size: var(--s-lg); line-height: 1.35; color: var(--ink); }
.feature .how { font-size: var(--s-sm); color: var(--muted); }
.result { font-size: var(--s-sm); padding-left: 0.8rem; border-left: 2px solid var(--signal); color: var(--ink); }
.links { display: flex; flex-wrap: wrap; gap: 0.35rem 1rem; font-size: var(--s-sm); font-weight: 600; }

.efficient { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.25rem; margin-top: 2rem; }
.eff { display: grid; gap: 0.6rem; align-content: start; padding: 1.25rem; border: 1px solid var(--rule); border-radius: 12px; background: var(--surface); min-width: 0; }
.eff h3 { font-size: var(--s-lg); }
.eff p { font-size: var(--s-sm); color: var(--muted); }
.eff .figure { font-family: var(--display); font-size: var(--s-md); color: var(--ink); }

/* Publications */
.pubs-head { max-width: none; grid-template-columns: minmax(0, 1fr) auto; align-items: end; }
.pubs-head h2, .pubs-head p { grid-column: 1; }
.filter { grid-column: 2; grid-row: 1 / span 2; display: flex; gap: 0.4rem; align-self: end; }
.filter .chip { padding: 0.35rem 0.85rem; }
.pubs { display: grid; gap: 1.75rem; }
.pub-year { display: grid; grid-template-columns: 4.5rem minmax(0, 1fr); gap: 1rem; }
.pub-year > h3 { font-family: var(--mono); font-weight: 500; font-size: var(--s-sm); color: var(--muted); padding-top: 0.15rem; font-variant-numeric: tabular-nums; }
.pub-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 1rem; }
.pub { display: grid; grid-template-columns: 10.5rem minmax(0, 1fr); gap: 1rem; padding-bottom: 1rem; border-bottom: 1px solid var(--rule); }
.pub:last-child { border-bottom: 0; padding-bottom: 0; }
.pub-venue { font-family: var(--mono); font-size: var(--s-xs); line-height: 1.5; color: var(--navy); padding-top: 0.2rem; }
.pub-venue em { display: block; font-style: normal; color: var(--signal); }
.pub-body { display: grid; gap: 0.2rem; min-width: 0; }
.pub-title { font-weight: 600; color: var(--ink); line-height: 1.4; }
.pub-title a { color: inherit; text-decoration: none; }
.pub-title a:hover { text-decoration: underline; color: var(--navy); }
.pub-authors { font-size: var(--s-sm); color: var(--muted); }
.pub-authors strong { color: var(--ink); font-weight: 600; }
.pub .links { font-size: var(--s-xs); font-family: var(--mono); font-weight: 500; gap: 0.2rem 0.9rem; }

/* Impact */
.impact { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.25rem; margin-bottom: 1.25rem; }
.impact-card { display: grid; gap: 0.85rem; align-content: start; padding: 1.4rem; background: var(--surface); border: 1px solid var(--rule); border-radius: 12px; min-width: 0; }
.impact-top { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: baseline; gap: 0.4rem 1rem; }
.impact-top h3 { font-size: var(--s-xl); color: var(--ink); }
.role { font-family: var(--mono); font-size: var(--s-xs); color: var(--signal); letter-spacing: 0.04em; }
.metrics { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); border-block: 1px solid var(--rule); }
.metric { display: grid; gap: 0.15rem; padding: 0.75rem 0.75rem 0.75rem 0; min-width: 0; }
.metric + .metric { padding-left: 0.9rem; border-left: 1px solid var(--rule); }
.metric b { font-family: var(--display); font-size: var(--s-xl); font-weight: 600; line-height: 1.1; color: var(--navy); font-variant-numeric: tabular-nums; }
.metric span { font-size: var(--s-xs); color: var(--muted); line-height: 1.35; }
.impact-what { font-size: var(--s-sm); color: var(--ink); }
.impact-mine { font-size: var(--s-sm); color: var(--muted); }
.impact-mine b { color: var(--ink); font-weight: 600; }
.impact-note { font-size: var(--s-xs); color: var(--muted); }

/* Repos */
.repos { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--rule); }
.repo { display: grid; grid-template-columns: minmax(0, 15rem) minmax(0, 1fr) 6.5rem; gap: 1rem 1.5rem; padding-block: 1rem; border-bottom: 1px solid var(--rule); align-items: baseline; }
.repo-name { display: grid; gap: 0.1rem; }
.repo-name a { font-weight: 600; text-decoration: none; }
.repo-name a:hover { text-decoration: underline; }
.repo-name span { font-family: var(--mono); font-size: var(--s-xs); color: var(--muted); }
.repo p { font-size: var(--s-sm); color: var(--muted); }
.stars { justify-self: end; font-family: var(--mono); font-size: var(--s-sm); color: var(--ink); font-variant-numeric: tabular-nums; white-space: nowrap; }
.stars b { font-weight: 400; }
.stars svg { width: 13px; height: 13px; vertical-align: -1px; color: var(--signal); }

/* Recognition and service */
.two-col { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: clamp(1.5rem, 5vw, 4rem); }
.plain-list { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--rule); }
.plain-list li { display: flex; justify-content: space-between; gap: 1rem; padding-block: 0.6rem; border-bottom: 1px solid var(--rule); font-size: var(--s-sm); }
.plain-list li span:last-child { color: var(--muted); text-align: right; }
.plain-list li.stack { display: grid; gap: 0.15rem; }
.plain-list li.stack span:last-child { text-align: left; }
.plain-list b { font-weight: 600; }

/* Background timeline */
.timeline { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--rule); }
.timeline li { display: grid; grid-template-columns: 9rem minmax(0, 1fr); gap: 1rem; padding-block: 0.65rem; border-bottom: 1px solid var(--rule); font-size: var(--s-sm); }
.timeline .when { font-family: var(--mono); color: var(--muted); font-variant-numeric: tabular-nums; }

/* Contact */
.contact { display: grid; gap: 0.9rem; padding-bottom: 1rem; }
.contact h2 { font-size: var(--s-xl); }
.contact > p { color: var(--muted); max-width: var(--read); }
.email-row { display: flex; flex-wrap: wrap; align-items: center; gap: 0.6rem 1rem; }
.email { font-family: var(--display); font-size: clamp(1.25rem, 1rem + 1.2vw, 1.75rem); font-weight: 500; overflow-wrap: anywhere; }
.copy-status { font-size: var(--s-xs); color: var(--muted); min-height: 1em; }
.elsewhere { display: flex; flex-wrap: wrap; gap: 0.4rem 1.25rem; font-size: var(--s-sm); font-weight: 600; }

.foot { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 0.5rem 1.5rem; padding-block: 2.5rem 2rem; margin-top: 3rem; border-top: 1px solid var(--rule); font-size: var(--s-xs); color: var(--muted); }

/* Responsive */
@media (max-width: 960px) {
  .theme { grid-template-columns: minmax(0, 1fr); }
  .impact { grid-template-columns: minmax(0, 1fr); }
  .efficient { grid-template-columns: minmax(0, 1fr); }
  .feature { grid-template-columns: minmax(0, 1fr); }
  .repo { grid-template-columns: minmax(0, 1fr) auto; }
  .repo p { grid-column: 1 / -1; grid-row: 2; }
}
@media (max-width: 700px) {
  .masthead { gap: 0.9rem; }
  .brand { font-size: var(--s-md); }
  .nav { gap: 1rem; }
  .hero { grid-template-columns: minmax(0, 1fr); }
  .portrait { order: -1; justify-self: start; max-width: 120px; }
  .news-list li { grid-template-columns: 3rem minmax(0, 1fr); gap: 0.15rem 0.75rem; }
  .news-list .t { grid-column: 2; }
  .efficient, .two-col { grid-template-columns: minmax(0, 1fr); }
  .pubs-head { grid-template-columns: minmax(0, 1fr); }
  .filter { grid-column: 1; grid-row: auto; }
  .pub-year { grid-template-columns: minmax(0, 1fr); gap: 0.5rem; }
  .pub { grid-template-columns: minmax(0, 1fr); gap: 0.3rem; }
  .timeline li { grid-template-columns: minmax(0, 1fr); gap: 0.1rem; }
}