/* Site styles. Plain CSS, no framework.
   Colors and fonts are tokens on :root; dark mode only redefines the tokens. */

/* Self-hosted variable fonts (SIL OFL, see public/fonts/LICENSE-*.txt), latin subset. */
@font-face {
  font-family: "Source Serif 4";
  src: url("/fonts/source-serif-4-latin-wght-normal.woff2") format("woff2");
  font-weight: 200 900;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Source Serif 4";
  src: url("/fonts/source-serif-4-latin-wght-italic.woff2") format("woff2");
  font-weight: 200 900;
  font-style: italic;
  font-display: swap;
}
@font-face {
  font-family: "Inter";
  src: url("/fonts/inter-latin-wght-normal.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}

:root {
  --font-body: "Source Serif 4", Georgia, "Times New Roman", serif;
  --font-head: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;

  /* light-dark(light value, dark value): the page follows the system setting,
     or the choice from the header button (data-theme on <html>). */
  --bg: light-dark(#ffffff, #121212);
  --fg: light-dark(#111111, #ececec);
  --muted: light-dark(#5b5b5b, #a3a3a3);
  --rule: light-dark(#e2e2e2, #2e2e2e);
  --surface: light-dark(#f5f5f3, #1d1d1d);
  --link: light-dark(#0a5bc4, #7cb7ff);
  --accent: light-dark(#111111, #ececec);     /* card borders, buttons, selection */
  --on-accent: light-dark(#ffffff, #121212);
  --shadow: light-dark(#cfcfcf, #3d3d3d);     /* brutalist card offset shadow */
  --amber: light-dark(#9a6b00, #e3b341);
  --teal: light-dark(#0f766e, #4fd1c5);
  --red: light-dark(#b42318, #ff7b72);

  --prose: 68ch;
  --wide: 1120px;
  --gutter: 1rem;
  --radius: 6px;
  color-scheme: light dark;
}
:root[data-theme="light"] { color-scheme: light; }
:root[data-theme="dark"] { color-scheme: dark; }

@media (min-width: 760px) {
  :root { --gutter: 1.5rem; }
}

/* ---------- base ---------- */

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-body);
  font-size: clamp(1.0625rem, 1rem + 0.25vw, 1.1875rem);
  line-height: 1.6;
  font-kerning: normal;
  -webkit-font-smoothing: antialiased;
}

main { flex: 1; }

h1, h2, h3, h4 {
  font-family: var(--font-head);
  line-height: 1.2;
  text-wrap: balance;
  margin: 2em 0 0.5em;
}
h1 { font-size: clamp(1.75rem, 1.4rem + 1.4vw, 2.6rem); font-weight: 700; letter-spacing: -0.02em; margin-top: 0; }
h2 { font-size: clamp(1.35rem, 1.2rem + 0.6vw, 1.7rem); font-weight: 700; letter-spacing: -0.02em; }
h3 { font-size: 1.15em; font-weight: 650; margin-top: 1.6em; }
h4 { font-size: 1em; font-weight: 650; }

p, ul, ol, pre, table, figure { margin: 0 0 1em; }
p { text-wrap: pretty; }
li + li { margin-top: 0.3em; }

a { color: var(--link); text-decoration-thickness: 1px; text-underline-offset: 0.18em; }
a:hover { text-decoration-thickness: 2px; }

img, video, svg { max-width: 100%; }
img, video { height: auto; display: block; }
video { width: 100%; background: #000; border-radius: 4px; }
picture { display: contents; }

code, pre { font-family: var(--font-mono); font-size: 0.875em; }
:not(pre) > code { background: var(--surface); padding: 0.1em 0.3em; border-radius: 3px; }
pre { background: var(--surface); padding: 1rem; border-radius: var(--radius); overflow-x: auto; line-height: 1.5; }

hr { border: 0; border-top: 1px solid var(--rule); margin: 2.5rem 0; }

::selection { background: var(--accent); color: var(--on-accent); }

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

.icon { width: 1em; height: 1em; vertical-align: -0.125em; flex: none; }

.skip-link {
  position: absolute;
  left: 0.5rem;
  top: -3rem;
  padding: 0.5rem 0.75rem;
  background: var(--accent);
  color: var(--on-accent);
  z-index: 10;
}
.skip-link:focus { top: 0.5rem; }

/* ---------- page grid: text column, wider column for figures ---------- */

.flow {
  display: grid;
  grid-template-columns:
    [full-start] minmax(var(--gutter), 1fr)
    [wide-start] minmax(0, calc((var(--wide) - var(--prose)) / 2))
    [prose-start] min(var(--prose), 100% - 2 * var(--gutter)) [prose-end]
    minmax(0, calc((var(--wide) - var(--prose)) / 2)) [wide-end]
    minmax(var(--gutter), 1fr) [full-end];
  padding-block: clamp(1.5rem, 1rem + 2vw, 3rem) 3rem;
}
.flow > * { grid-column: prose; min-width: 0; }
.flow > figure,
.flow > .cols,
.flow > .wide,
.flow > .table-wrap,
.flow > .math,
.flow > .paper-header,
.flow-wide > * { grid-column: wide; }
.flow > figure[style*="max-width"] { justify-self: center; width: 100%; }

/* ---------- header / footer ---------- */

/* Header and footer have the width of the content column; their black line ends with it. */
.site-nav,
.site-footer-inner {
  width: min(var(--wide), 100% - 2 * var(--gutter));
  margin: 0 auto;
  padding: 0.9rem 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
}
.site-name {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--fg);
  text-decoration: none;
}
.site-nav ul { display: flex; gap: 1.25rem; list-style: none; margin: 0; padding: 0; }
.site-nav li + li { margin: 0; }
.site-nav ul { align-items: center; }
.site-nav ul a {
  font-family: var(--font-head);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--muted);
  text-decoration: none;
}
.name-short { display: none; }
/* Phones: first name only, so the name, links and theme button fit in one row. */
@media (max-width: 600px) {
  .site-nav { flex-wrap: nowrap; }
  .site-nav ul { gap: 0.9rem; }
  .name-full { display: none; }
  .name-short { display: inline; }
}
.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.35rem 0.5rem;
  margin-right: -0.5rem;
  font: inherit;
  color: var(--rule);
  background: none;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
}
.theme-toggle:hover { background: var(--surface); }
.theme-toggle .icon { width: 1.05rem; height: 1.05rem; color: var(--muted); opacity: 0.45; transition: opacity 0.15s; }
/* The icon of the current theme is in full color: sun in light mode, moon in dark mode. */
.theme-toggle .icon:first-child,
:root[data-theme="dark"] .theme-toggle .icon:last-child { color: var(--fg); opacity: 1; }
:root[data-theme="dark"] .theme-toggle .icon:first-child { color: var(--muted); opacity: 0.45; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .icon:first-child { color: var(--muted); opacity: 0.45; }
  :root:not([data-theme="light"]) .theme-toggle .icon:last-child { color: var(--fg); opacity: 1; }
}
.site-nav ul a:hover,
.site-nav ul a[aria-current="page"] { color: var(--fg); text-decoration: underline; text-decoration-thickness: 2px; text-underline-offset: 0.5em; }

.site-nav { border-bottom: 2px solid var(--accent); }
.site-footer { font-size: 0.875rem; color: var(--muted); }
.site-footer-inner { border-top: 2px solid var(--accent); }
.site-footer p { margin: 0; }

.socials { display: flex; gap: 0.25rem; list-style: none; margin: 0; padding: 0; }
.socials li + li { margin: 0; }
.socials a { display: grid; place-items: center; width: 2.5rem; height: 2.5rem; color: var(--fg); border-radius: 50%; }
.socials a:hover { background: var(--surface); }
.socials .icon { width: 1.3rem; height: 1.3rem; }

/* ---------- homepage ---------- */

/* Phone: small round photo next to the name.
   Wider: under the name, the photo floats on the right (aligned with the cards) and the bio wraps around it. */
.intro { display: grid; gap: 0 2.5rem; }
.intro-head { display: grid; grid-template-columns: 84px 1fr; gap: 1rem; align-items: center; margin-bottom: 0.75rem; }
.intro-head h1 { margin: 0; grid-column: 2; grid-row: 1; }
.portrait { grid-column: 1; grid-row: 1; width: 100%; aspect-ratio: 1; object-fit: cover; border-radius: 50%; border: 1px solid var(--rule); }
.contact { display: flex; flex-wrap: wrap; align-items: center; gap: 0.25rem 1rem; }
.contact .socials { margin-left: -0.6rem; }
@media (min-width: 760px) {
  .intro { display: flow-root; }
  .intro-head { display: contents; }
  /* margin-top lines the photo up with the capital letters of the first text line */
  .portrait { float: right; width: clamp(170px, 16vw, 220px); margin: 0.4em 0 1rem 2.5rem; border-radius: var(--radius); }
  .intro-head h1 { margin-bottom: 0.5rem; }
}

/* News: one row of up to three items between two thin gray rules (black lines are for the page frame). */
.news { margin: 1.75rem 0 2.5rem; padding: 1rem 0; border-block: 1px solid var(--rule); }
.news ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.75rem 2rem; grid-template-columns: repeat(auto-fit, minmax(min(100%, 240px), 1fr)); font-size: 0.9rem; }
.news li { margin: 0; }
.news strong { display: block; font-family: var(--font-head); font-size: 0.8rem; letter-spacing: 0.02em; }
.research > h2 { margin-top: 0; }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

/* ---------- project cards ---------- */

.card {
  position: relative;
  display: grid;
  gap: 1rem 1.5rem;
  padding: 1rem;
  margin-bottom: 1.5rem;
  background: var(--bg);
  border: 1.5px solid var(--accent);
  border-radius: var(--radius);
  box-shadow: 4px 4px 0 var(--shadow);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.card:hover { transform: translate(2px, 2px); box-shadow: 2px 2px 0 var(--shadow); }
@media (min-width: 760px) {
  .card { grid-template-columns: 280px 1fr; align-items: center; padding: 1.25rem; }
}
/* Covers keep their own shape (nothing is cropped); 4:3 covers look best. */
.card-media { border-radius: 4px; overflow: hidden; }
.card-media img, .card-media video { width: 100%; height: auto; border-radius: 0; }
.card-body { min-width: 0; }
.card h3 { margin: 0 0 0.35rem; font-size: 1.15rem; }
.card-link { color: var(--fg); text-decoration: none; }
.card-link::after { content: ""; position: absolute; inset: 0; border-radius: var(--radius); }
.card .meta, .card .venue { margin: 0 0 0.25rem; font-size: 0.875rem; color: var(--muted); }
.card .venue { font-style: italic; }
.card .description {
  margin: 0.5rem 0;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.links { margin: 0; font-size: 0.875rem; font-weight: 600; display: flex; flex-wrap: wrap; gap: 0.25rem 1rem; }
.links a { position: relative; z-index: 1; color: var(--muted); text-decoration: none; }
.links a:hover { color: var(--fg); text-decoration: underline; }
/* "project page / code / arxiv" on the homepage cards */
.card .links { gap: 0.25rem 0.5rem; }
.card .links a + a::before {
  content: "/";
  display: inline-block; /* keeps the hover underline off the slash */
  margin-right: 0.5rem;
  color: var(--muted);
  opacity: 0.6;
  font-weight: 400;
}

/* ---------- publications ---------- */

.pub-year h2 { border-bottom: 2px solid var(--accent); padding-bottom: 0.25rem; }
.pubs { list-style: none; padding: 0; }
.pub { display: grid; gap: 1.25rem; padding: 1rem 0; border-bottom: 1px solid var(--rule); }
.pubs li + li { margin: 0; }
.pub-thumb { display: none; }
@media (min-width: 640px) {
  .pub:has(.pub-thumb) { grid-template-columns: 120px 1fr; }
  .pub-thumb { display: block; }
  .pub-thumb img { width: 120px; aspect-ratio: 1; object-fit: cover; border-radius: 4px; border: 1px solid var(--rule); }
}
.pub-body { min-width: 0; }
.pub-body p { margin: 0 0 0.2rem; }
.pub-title { font-weight: 650; }
.pub-label { color: var(--muted); font-variant-numeric: tabular-nums; margin-right: 0.25rem; }
.pub-authors, .pub-venue { font-size: 0.925rem; color: var(--muted); }
.pub-authors strong { color: var(--fg); font-weight: 600; }
.award { color: var(--fg); font-weight: 600; }
.pub .links { margin-top: 0.4rem; }
.toggle {
  font: inherit;
  color: var(--muted);
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}
.toggle::before { content: "\25B8\00a0"; display: inline-block; transition: transform 0.15s; }
.toggle[aria-expanded="true"]::before { transform: rotate(90deg); }
.toggle:hover { color: var(--fg); }
.panel { margin-top: 0.75rem; font-size: 0.925rem; }
.panel > p { background: var(--surface); padding: 1rem; border-radius: var(--radius); }

.bibtex { position: relative; }
.bibtex pre { margin: 0; padding-right: 5.5rem; white-space: pre-wrap; overflow-wrap: anywhere; }
.copy {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font: inherit;
  font-size: 0.8rem;
  padding: 0.25rem 0.6rem;
  color: var(--fg);
  background: var(--bg);
  border: 1px solid var(--accent);
  border-radius: 999px;
  cursor: pointer;
}
.copy:hover { background: var(--accent); color: var(--on-accent); }

/* ---------- research page ---------- */

.paper-header { text-align: center; margin-bottom: 1.5rem; }
.paper-header h1 { max-width: 28ch; margin-inline: auto; }
.authors, .affiliations { display: flex; flex-wrap: wrap; justify-content: center; gap: 0.25rem 1.1rem; margin: 0.75rem 0 0; }
.authors { font-size: 1.05em; }
.authors a, .affiliations a { color: inherit; }
.affiliations { color: var(--muted); font-size: 0.925em; }
.buttons { display: flex; flex-wrap: wrap; justify-content: center; gap: 0.5rem; margin: 1.25rem 0 0; }
.button {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.45rem 1rem;
  font-size: 0.925rem;
  font-weight: 600;
  color: var(--on-accent);
  background: var(--accent);
  border: 1.5px solid var(--accent);
  border-radius: 999px;
  text-decoration: none;
}
.button:hover { color: var(--fg); background: var(--bg); }
.button[aria-disabled="true"] { color: var(--muted); background: transparent; border-color: var(--rule); }
.note { color: var(--muted); font-size: 0.9em; margin-top: 0.75rem; }

figure { margin: 1.5rem 0 2rem; }
figure img { margin-inline: auto; border-radius: 2px; }
figcaption, .caption { font-size: 0.875rem; color: var(--muted); margin-top: 0.6rem; line-height: 1.5; }
.flow > .caption { margin-top: -1rem; }

.cols { display: grid; gap: 1.5rem; margin: 1.5rem 0 2rem; }
.cols > * { min-width: 0; }
.cols figure { margin: 0 0 1rem; }
.cols > div > :last-child { margin-bottom: 0; }
.first-on-mobile { order: -1; }
@media (min-width: 900px) {
  .cols { grid-template-columns: var(--cols, 1fr 1fr); gap: 2rem; }
  .cols.center { align-items: center; }
  .first-on-mobile { order: 0; }
}
figure > .cols { margin: 0; }

.grid { display: grid; gap: 0.75rem; grid-template-columns: repeat(auto-fit, minmax(min(100%, 260px), 1fr)); }
@media (min-width: 760px) { .grid { grid-template-columns: repeat(var(--cols, 2), 1fr); } }
.grid img, .grid video { width: 100%; }

.small { font-size: 0.925em; }
.eyebrow { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); margin-top: 0; }

.steps { list-style: none; padding: 0; counter-reset: step; display: grid; gap: 1rem; }
.steps li { counter-increment: step; margin: 0; }
.steps li::before { content: counter(step) "."; font-weight: 700; margin-right: 0.4rem; }
@media (min-width: 760px) { .flow > .steps { grid-column: wide; grid-template-columns: repeat(3, 1fr); } }

.hl-amber { color: var(--amber); font-weight: 600; }
.hl-teal { color: var(--teal); font-weight: 600; }
.hl-red { color: var(--red); font-weight: 600; }

.table-wrap { overflow-x: auto; margin: 1.5rem 0 1rem; }
table { width: 100%; border-collapse: collapse; font-size: 0.875rem; font-variant-numeric: tabular-nums; }
th, td { padding: 0.45rem 0.6rem; border-bottom: 1px solid var(--rule); text-align: center; vertical-align: middle; }
th:first-child, td:first-child { text-align: left; }
thead th { border-bottom: 2px solid var(--accent); font-weight: 600; }
thead tr + tr th { font-weight: 400; color: var(--muted); }
tr.ours { font-weight: 650; }

.math, mjx-container[display="true"] { overflow-x: auto; overflow-y: hidden; max-width: 100%; }

/* ---------- posts / pages ---------- */

.lead { font-size: 1.2em; color: var(--muted); }
.meta { color: var(--muted); font-size: 0.925rem; }
.post-header .meta { margin-top: -0.25rem; }
.toc { margin: 1rem 0 2rem; padding: 0.75rem 1rem; background: var(--surface); border-radius: var(--radius); }
.toc summary { cursor: pointer; font-weight: 600; }
.toc ol { margin: 0.5rem 0 0; padding-left: 1.25rem; }
.post-list { list-style: none; padding: 0; }
.post-list h2 { margin: 1.5rem 0 0.25rem; font-size: 1.3rem; }

/* ---------- code highlighting (Prism classes) ---------- */

.token.comment, .token.prolog { color: var(--muted); font-style: italic; }
.token.keyword, .token.tag, .token.boolean { color: var(--red); }
.token.string, .token.attr-value { color: var(--teal); }
.token.number, .token.function, .token.class-name { color: var(--amber); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; }
}