/* BUCOLIN lab site.
   One stylesheet for every page. Colours and fonts are set up as variables
   at the top; the dark theme only overrides the colours.

   Two widths matter: below 60rem the menu folds away and the margin labels
   move above their sections, and below 40rem everything is one column. */

:root {
  --serif: "Source Serif 4", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --sans: "Source Sans 3", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: "Source Code Pro", ui-monospace, "SF Mono", Menlo, Consolas, monospace;

  /* text sizes, the same on every page; smaller on phones (see the end of the file) */
  --size-large: 1.375rem;  /* intros, the first sentence of a news item, titles and names */
  --size-prose: 1.125rem;  /* the rest of a news item, paper titles */

  --bg: #f7f5ef;
  --surface: #fdfcf9;
  --text: #1b1e26;
  --muted: #5a5f6b;
  --border: #ddd8cb;
  --rule: #8a8474;
  --accent: #2f6fd8;
  --link: #1f4fb2;
  --link-hover: #1b2a9b;
  --selection: #dde7f8;

  /* the three blues of the logo, left to right */
  --mark-1: #5aa5f5;
  --mark-2: #2f6fd8;
  --mark-3: #1b2a9b;

  --tag-paper: #1f4fb2;     --tag-paper-bg: #e2eaf8;
  --tag-award: #7a5200;     --tag-award-bg: #f3e6c4;
  --tag-people: #9a3f25;    --tag-people-bg: #f5e0d7;
  --tag-resource: #0e6470;  --tag-resource-bg: #d8ecec;

  --wrap: 72rem;
  --gutter: clamp(1rem, 4vw, 2.5rem);
  --rail: 11rem;
  --header: 4rem;

  color-scheme: light;
}

/* screens only, so that a printout always gets the light colours */
@media screen {
  :root[data-theme="dark"] {
    --bg: #0f1319;
    --surface: #161b23;
    --text: #e9e5db;
    --muted: #a0a6b2;
    --border: #272d38;
    --rule: #5c6474;
    --accent: #6aa6f4;
    --link: #8dbbf8;
    --link-hover: #c2dafd;
    --selection: #1b2c4a;

    /* navy disappears on a dark page, so the gradient is lifted */
    --mark-1: #8fc3ff;
    --mark-2: #5aa5f5;
    --mark-3: #7c8df0;

    --tag-paper: #9cc3fa;     --tag-paper-bg: #17253d;
    --tag-award: #e6be6a;     --tag-award-bg: #2e2510;
    --tag-people: #eba089;    --tag-people-bg: #34201a;
    --tag-resource: #7fcbd3;  --tag-resource-bg: #10292d;

    color-scheme: dark;
  }
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: calc(var(--header) + 1rem);
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  font: 400 1.0625rem/1.6 var(--sans);
}

main { flex: 1; }

::selection { background: var(--selection); }

h1, h2, h3, p, ul, ol, dl, dd, figure { margin: 0; }
ul, ol { padding: 0; list-style: none; }

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

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

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

.skip {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 20;
  padding: 0.5rem 0.75rem;
  background: var(--surface);
  border: 1px solid var(--rule);
}
.skip:focus { top: 0.5rem; }


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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}

.bar {
  display: flex;
  align-items: center;
  gap: 2rem;
  height: var(--header);
}

.wordmark {
  font: 800 1.5rem/1 var(--sans);
  letter-spacing: 0.01em;
  text-decoration: none;
  color: var(--mark-2);
  background: linear-gradient(90deg, var(--mark-1), var(--mark-2) 55%, var(--mark-3));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.site-nav { margin-left: auto; }
.site-nav ul { display: flex; gap: 1.5rem; }
.site-nav a {
  display: block;
  line-height: var(--header);
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--muted);
  text-decoration: none;
  /* the bar sits on the header's own bottom border */
  box-shadow: inset 0 -2px 0 transparent;
}
.site-nav a:hover { color: var(--text); }
.site-nav a[aria-current="page"] {
  color: var(--text);
  box-shadow: inset 0 -2px 0 var(--accent);
}

.tools {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.tools button {
  height: 2.5rem;
  min-width: 2.5rem;
  padding-inline: 0.5rem;
  border-radius: 2px;
  color: var(--muted);
}
.tools button:hover { color: var(--text); }

.lang-switch {
  font: 500 0.8125rem/1 var(--mono);
  letter-spacing: 0.02em;
}
.lang-switch .on { color: var(--text); }
.lang-switch .sep { margin-inline: 0.3em; opacity: 0.5; }

.theme-switch svg { display: block; margin: auto; }

.menu-toggle {
  display: none;
  font: 500 0.8125rem/1 var(--mono);
}

@media (max-width: 59.99rem) {
  :root { --header: 3.5rem; }

  .bar { gap: 0.5rem; }
  .tools { margin-left: auto; }
  .menu-toggle { display: block; }

  .site-nav {
    display: none;
    position: absolute;
    inset: 100% 0 auto;
    margin: 0;
    padding: 0.5rem var(--gutter) 1.5rem;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    /* on a phone held sideways the list is taller than the screen */
    max-height: calc(100vh - var(--header));
    max-height: calc(100dvh - var(--header));
    overflow-y: auto;
    overscroll-behavior: contain;
  }
  .site-header[data-open] .site-nav { display: block; }

  .site-nav ul { display: block; }
  .site-nav li + li { border-top: 1px solid var(--border); }
  .site-nav a {
    padding-block: 0.75rem;
    font: 400 1.375rem/1.3 var(--serif);
    color: var(--text);
    box-shadow: none;
  }
  .site-nav a[aria-current="page"] {
    box-shadow: none;
    color: var(--link);
    font-weight: 600;
  }
}


/* ---------- page head ---------- */

.page-head {
  padding-block: 3.5rem 3rem;
  /* lines up with the content column of the sections below */
  padding-left: calc(var(--rail) + 3rem);
}

.page-head h1 {
  font: 600 clamp(2.25rem, 1.6rem + 2.6vw, 3.25rem)/1.1 var(--serif);
  letter-spacing: -0.015em;
  text-wrap: balance;
}

/* the page title in the other language, set under it like an interlinear gloss */
.gloss {
  display: block;
  margin-top: 0.6rem;
  font: 400 0.8125rem/1 var(--mono);
  letter-spacing: 0.04em;
  color: var(--muted);
}

.lead {
  max-width: 40rem;
  margin-top: 1.25rem;
  font: 400 var(--size-large)/1.5 var(--serif);
}


/* ---------- sections: a label in the margin, content beside it ---------- */

.section {
  display: grid;
  grid-template-columns: var(--rail) minmax(0, 1fr);
  column-gap: 3rem;
  padding-block: 2.5rem;
  border-top: 1px solid var(--border);
}
main > .section:last-child { padding-bottom: 5rem; }

.label {
  position: sticky;
  top: calc(var(--header) + 1.5rem);
  align-self: start;
  padding-top: 0.3rem;
  font: 600 0.8125rem/1.4 var(--sans);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}
.label .count {
  margin-left: 0.15em;
  font: 400 0.8125rem/1 var(--mono);
  letter-spacing: 0;
}
.label.year {
  padding-top: 0;
  font: 400 1.75rem/1.2 var(--serif);
  letter-spacing: 0;
  color: var(--text);
}

.more {
  display: inline-block;
  margin-top: 1.5rem;
  font-size: 0.9375rem;
  font-weight: 500;
}

@media (max-width: 59.99rem) {
  .page-head { padding-block: 2.5rem 2rem; padding-left: 0; }
  .section { display: block; padding-block: 2rem; }
  .label { position: static; margin-bottom: 1.25rem; padding-top: 0; }
  .label.year { margin-bottom: 1rem; }
}



/* ---------- entries (news items and projects) ---------- */

.entry { padding-block: 1.5rem; }
.entry + .entry { border-top: 1px solid var(--border); }
.entry:first-child { padding-top: 0; }
.entry:last-child { padding-bottom: 0; }

.entry h3 {
  max-width: 46rem;
  font: 600 var(--size-large)/1.3 var(--serif);
  text-wrap: balance;
}
.entry h3 a { color: inherit; text-decoration: none; }
.entry h3 a:hover { color: var(--link); text-decoration: underline; }

.entry p { max-width: 42rem; }
.entry h3 + p, .entry .kicker + p { margin-top: 0.4rem; }

.kicker {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 0.75rem;
}

.meta {
  font: 400 0.8125rem/1.5 var(--mono);
  color: var(--muted);
}
.entry h3 + .meta { margin-top: 0.35rem; }

.muted { color: var(--muted); }

/* looks like an entity label in an annotation tool, which is the idea */
.tag {
  padding: 0.2rem 0.4rem;
  font: 500 0.75rem/1 var(--mono);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border-radius: 2px;
  color: var(--tag-paper);
  background: var(--tag-paper-bg);
}
.tag[data-tag="award"] { color: var(--tag-award); background: var(--tag-award-bg); }
.tag[data-tag="people"] { color: var(--tag-people); background: var(--tag-people-bg); }
.tag[data-tag="resource"] { color: var(--tag-resource); background: var(--tag-resource-bg); }

.links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.25rem;
  margin-top: 0.75rem;
  font-size: 0.9375rem;
  font-weight: 500;
}

/* a word and the arrow or number that belongs with it, kept on one line */
.keep { white-space: nowrap; }
.keep svg { margin-left: 0.2em; }

/* further lines under a news item */
.more-lines { max-width: 42rem; margin-top: 0.75rem; }
.more-lines li + li { margin-top: 0.35rem; }

/* a paper, set as a reference */
.reference {
  max-width: 46rem;
  line-height: 1.55;
  color: var(--muted);
}
.reference + .reference { margin-top: 1rem; }
.reference .title { font: 600 var(--size-prose)/1.4 var(--serif); color: var(--text); }
.reference a.title { text-decoration-color: var(--rule); }
.reference a.title:hover { color: var(--link); text-decoration-color: currentColor; }
.reference:target .title { color: var(--link); }

/* the papers of a project, under it */
.papers {
  margin-top: 1rem;
  padding-left: 1rem;
  border-left: 1px solid var(--rule);
}


/* ---------- home ---------- */

.hero {
  padding-block: 3.5rem 4rem;
  /* lines up with the content column of the sections below */
  padding-left: calc(var(--rail) + 3rem);
}

/* The lab logo, as a background so that the dark theme can swap in its own
   version (the original's navy lettering cannot be read on a dark page). */
.logo {
  width: min(100%, 32rem);
  aspect-ratio: 736 / 486;
  background: url(../img/logo.png) center / contain no-repeat;
}
:root[data-theme="dark"] .logo { background-image: url(../img/logo-dark.png); }

.hero .lead { max-width: 44rem; margin-top: 2rem; }
.hero .links { margin-top: 1.75rem; font-size: 1rem; }

@media (max-width: 59.99rem) {
  .hero { padding-block: 2rem 2.5rem; padding-left: 0; }
}


/* ---------- news ---------- */

.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1.75rem;
}
.filters button {
  padding: 0.3rem 0.7rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--muted);
  border: 1px solid var(--border);
  border-radius: 2px;
}
.filters button:hover { color: var(--text); border-color: var(--rule); }
.filters button[aria-pressed="true"] {
  color: var(--bg);
  background: var(--text);
  border-color: var(--text);
}


/* ---------- people ---------- */

.people {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0 3rem;
}
.person {
  padding-block: 1rem;
  border-top: 1px solid var(--border);
}
/* the top row of the grid needs no rule above it */
.people .person:nth-child(-n + 2) { border-top: 0; padding-top: 0; }

.person .name { font: 600 var(--size-large)/1.3 var(--serif); color: var(--text); }
.person p { color: var(--muted); }
.person a { color: inherit; }
.person .links { margin-top: 0.3rem; }
.person a:hover { color: var(--link); }
.person .name a { text-decoration: none; }
.person .name a:hover { text-decoration: underline; }

.people.faculty { grid-template-columns: minmax(0, 1fr); }
.people.faculty .person:nth-child(2) { border-top: 1px solid var(--border); padding-top: 1rem; }
.people.faculty .name { font-size: 1.75rem; }

@media (max-width: 39.99rem) {
  .people { grid-template-columns: minmax(0, 1fr); }
  .people .person:nth-child(2) { border-top: 1px solid var(--border); padding-top: 1rem; }
}


/* ---------- contact ---------- */

.contact address { font-style: normal; }
.contact li + li { margin-top: 0.3rem; }


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

.site-footer {
  margin-top: 2rem;
  border-top: 1px solid var(--border);
  font-size: 0.9375rem;
  color: var(--muted);
}
.site-footer .cols {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1fr) minmax(0, 1fr);
  gap: 2rem 3rem;
  padding-block: 3rem;
}
.site-footer .wordmark { font-size: 1.25rem; }
.site-footer .about p { max-width: 24rem; margin-top: 0.75rem; }
.site-footer h2 {
  margin: 0 0 0.6rem;
  font: 600 0.75rem/1.4 var(--sans);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.site-footer li + li { margin-top: 0.3rem; }
.site-footer a { color: inherit; text-decoration: none; }
.site-footer a:hover { color: var(--link); text-decoration: underline; }

@media (max-width: 39.99rem) {
  .site-footer .cols { grid-template-columns: minmax(0, 1fr); }
}


noscript p { padding-block: 3rem; max-width: 40rem; }

@media (max-width: 39.99rem) {
  :root { --size-large: 1.25rem; --size-prose: 1.0625rem; }
}

@media (prefers-reduced-motion: no-preference) {
  a, button { transition: color 120ms ease-out, background-color 120ms ease-out, border-color 120ms ease-out; }
}

/* Windows high contrast drops backgrounds and shadows, which is all that
   marked the chosen filter and the current page */
@media (forced-colors: active) {
  .filters button[aria-pressed="true"] {
    forced-color-adjust: none;
    background: Highlight;
    color: HighlightText;
    border-color: Highlight;
  }
  .site-nav a[aria-current="page"] { text-decoration: underline; text-underline-offset: 0.4em; }
}

@media print {
  .site-header, .site-footer .cols, .filters, .skip { display: none; }
  body { background: #fff; }
}