/* U-Chrom Atlas: an editorial page. Serif headings, warm paper, thin rules; the four colours of the U-Chrom
   logo mark the kinds of data (contact maps red, RNA green, compartments blue, accessibility orange). */
:root {
  --paper: #fbfaf7; --ink: #1c1d21; --ink-2: #3f4148; --muted: #73767d; --rule: #e5e1d8; --rule-2: #d6d1c5;
  --panel: #f2efe8; --accent: #3651a2; --accent-ink: #2b4387;
  --hic: #be2d2a; --rna: #5b8f34; --ab: #3651a2; --atac: #dc740d; --img: #8a8578; --xyz: #7e5aa6;
  --serif: "Newsreader", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --map-filter: none; color-scheme: light;
  --logo-green: #2a9d8f; --logo-blue: #34568b; --logo-orange: #e07a3f;      /* logo.svg */
}
/* dark: by the system's setting unless the page's toggle chose a theme (theme.js sets data-theme) */
:root[data-theme="dark"] {
  --paper: #141519; --ink: #eceae4; --ink-2: #c9c7c1; --muted: #9a9a95; --rule: #2a2b31; --rule-2: #3a3b42;
  --panel: #1d1e23; --accent: #93a9ea; --accent-ink: #b5c5f2;
  --hic: #e0605a; --rna: #8cc063; --ab: #93a9ea; --atac: #f0a04b; --img: #a9a49a; --xyz: #b394d6;
  --map-filter: brightness(.82) contrast(1.06); color-scheme: dark;
  --logo-green: #4fbfb0; --logo-blue: #8aa6dc; --logo-orange: #f0955c;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #141519; --ink: #eceae4; --ink-2: #c9c7c1; --muted: #9a9a95; --rule: #2a2b31; --rule-2: #3a3b42;
    --panel: #1d1e23; --accent: #93a9ea; --accent-ink: #b5c5f2;
    --hic: #e0605a; --rna: #8cc063; --ab: #93a9ea; --atac: #f0a04b; --img: #a9a49a; --xyz: #b394d6;
    --map-filter: brightness(.82) contrast(1.06); color-scheme: dark;
  --logo-green: #4fbfb0; --logo-blue: #8aa6dc; --logo-orange: #f0955c;
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 15px/1.6 var(--sans);
  -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-ink); text-decoration: underline; text-underline-offset: 3px; }
img { display: block; max-width: 100%; }
.wrap { max-width: 1180px; margin: 0 auto; padding: 0 28px; }

/* top bar */
.top { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--paper) 90%, transparent);
  backdrop-filter: saturate(1.4) blur(10px); -webkit-backdrop-filter: saturate(1.4) blur(10px); border-bottom: 1px solid var(--rule); }
.bar { display: flex; align-items: center; justify-content: space-between; height: 58px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); font: 500 17px/1 var(--sans); letter-spacing: -.01em; }
.brand:hover { color: var(--ink); text-decoration: none; }
.brand em { font: italic 400 19px/1 var(--serif); color: var(--ink-2); }
nav { display: flex; align-items: center; gap: 26px; font-size: 14px; }
nav a { color: var(--muted); } nav a:hover { color: var(--ink); text-decoration: none; }
.theme-toggle { display: inline-grid; place-items: center; width: 32px; height: 32px; margin: 0 -6px 0 -8px; padding: 0;
  border: 0; border-radius: 50%; background: none; color: var(--muted); cursor: pointer; }
.theme-toggle:hover { color: var(--ink); background: var(--panel); }
.theme-toggle:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.theme-toggle svg { width: 17px; height: 17px; }
.theme-toggle .sun, :root[data-theme="dark"] .theme-toggle .moon { display: none; }
:root[data-theme="dark"] .theme-toggle .sun { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .moon { display: none; }
  :root:not([data-theme="light"]) .theme-toggle .sun { display: block; }
}

/* hero */
.hero { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 56px; align-items: center; padding-top: 72px; padding-bottom: 72px; }
h1 { margin: 0 0 24px; font: 400 clamp(40px, 5.4vw, 66px)/1.04 var(--serif); letter-spacing: -.022em; }
h1 span { white-space: nowrap; }
.lead { max-width: 30em; margin: 0 0 30px; color: var(--ink-2); font-size: 17.5px; line-height: 1.6; }
.cta { display: inline-flex; gap: 8px; align-items: center; padding: 11px 20px; border-radius: 999px; background: var(--ink); color: var(--paper);
  font-weight: 500; font-size: 15px; transition: transform .15s ease; }
.cta:hover { color: var(--paper); text-decoration: none; transform: translateY(1px); }
.stats { display: grid; grid-template-columns: repeat(4, auto); justify-content: start; gap: 0; margin: 44px 0 0; }
.stats div { padding: 0 26px; border-left: 1px solid var(--rule-2); }
.stats div:first-child { padding-left: 0; border-left: 0; }
.stats dd { order: -1; margin: 0; font: 400 34px/1.1 var(--serif); letter-spacing: -.01em; }
.stats div { display: flex; flex-direction: column; }
.stats dt { color: var(--muted); font-size: 13px; }

.hero-anim { margin: 0; }
.hero-anim canvas { display: block; width: 100%; aspect-ratio: 1; }
.hero-failed canvas { display: none; }
.hero-fig { margin: 0; }
.panels { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.panel { position: relative; display: block; aspect-ratio: 1; padding: 6%; background: var(--panel); border-radius: 4px; overflow: hidden; }
.panel img { width: 100%; height: 100%; object-fit: contain; transition: transform .4s ease; }
a.panel:hover img { transform: scale(1.03); }
.panel.map { padding: 0; }
.panel.map img { object-fit: cover; image-rendering: pixelated; filter: var(--map-filter); }
.letter { position: absolute; top: 8px; left: 8px; z-index: 1; padding: 3px 6px; border-radius: 3px; background: var(--paper);
  color: var(--ink); font: 600 12px/1 var(--sans); }
figcaption { margin-top: 14px; color: var(--muted); font-size: 13px; line-height: 1.55; }

/* catalogue */
.catalog { padding-top: 56px; border-top: 1px solid var(--rule); }
.toolbar { display: flex; align-items: end; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.section-title { margin: 0; font: 400 40px/1.1 var(--serif); letter-spacing: -.015em; }
#q { width: min(100%, 340px); padding: 10px 14px; font: inherit; font-size: 14.5px; color: var(--ink); background: transparent;
  border: 1px solid var(--rule-2); border-radius: 999px; }
#q::placeholder { color: var(--muted); }
#q:focus { outline: none; border-color: var(--ink-2); }
.chips { display: flex; flex-wrap: wrap; gap: 10px 28px; margin: 22px 0 0; }
.grp { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }
.grp-name { margin-right: 4px; color: var(--muted); font-size: 12px; letter-spacing: .06em; text-transform: uppercase; }
.chip { padding: 4px 12px; border: 1px solid var(--rule-2); border-radius: 999px; background: transparent; color: var(--ink-2);
  font: inherit; font-size: 13px; cursor: pointer; transition: background .15s, color .15s, border-color .15s; }
.chip:hover { border-color: var(--ink-2); color: var(--ink); }
.chip.on { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.hint { margin: 18px 0 0; color: var(--muted); font-size: 13px; }

.results { display: flex; align-items: baseline; gap: 14px; margin-top: 44px; padding-bottom: 10px; border-bottom: 1px solid var(--ink);
  scroll-margin-top: 76px; }
.results h3 { margin: 0; font: 400 26px/1.2 var(--serif); letter-spacing: -.01em; }
.results span { color: var(--muted); font-size: 13px; }
.pager { display: flex; flex-wrap: wrap; justify-content: center; align-items: center; gap: 8px; margin: 8px 0 0; padding-top: 32px;
  border-top: 1px solid var(--rule); }
.pager button { min-width: 36px; height: 36px; padding: 0 12px; border: 1px solid var(--rule-2); border-radius: 999px; background: transparent;
  color: var(--ink-2); font: inherit; font-size: 14px; cursor: pointer; transition: background .15s, color .15s, border-color .15s; }
.pager button:hover:not(:disabled) { border-color: var(--ink-2); color: var(--ink); }
.pager .pg.on { background: var(--ink); border-color: var(--ink); color: var(--paper); cursor: default; }
.pager .pg-step { border-color: transparent; }
.pager button:disabled { opacity: .35; cursor: default; }
.study { display: grid; grid-template-columns: 270px minmax(0, 1fr); gap: 48px; padding: 48px 0; border-bottom: 1px solid var(--rule); }
.study, .card { scroll-margin-top: 76px; }                      /* a link to #id: below the sticky bar */
.study:last-child { border-bottom: 0; }
.study-head { position: sticky; top: 86px; align-self: start; }
.kind { margin: 0 0 10px; color: var(--hic); font-size: 12px; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; }
.study-head h3 { margin: 0; font: 400 30px/1.15 var(--serif); letter-spacing: -.01em; }
.journal { display: block; margin-top: 2px; color: var(--muted); font: italic 400 19px/1.3 var(--serif); }
.paper { margin: 14px 0 0; color: var(--ink-2); font: 400 16px/1.45 var(--serif); }
.summary { margin: 12px 0 0; color: var(--muted); font-size: 14px; }
.links { margin: 14px 0 0; color: var(--muted); font-size: 13px; }

.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 260px), 1fr)); gap: 34px 28px; }
.card { display: flex; flex-direction: column; min-width: 0; }
.fig-link { display: block; }
.fig { display: grid; grid-template-columns: 1fr 1fr; grid-template-rows: minmax(0, 1fr); aspect-ratio: 2 / 1; background: var(--panel); border-radius: 4px; overflow: hidden; }
.fig img { width: 100%; height: 100%; min-height: 0; object-fit: contain; padding: 7%; transition: transform .4s ease; }
.fig img.map { padding: 0; object-fit: cover; image-rendering: pixelated; filter: var(--map-filter); }
.fig.single { grid-template-columns: 1fr; }
.fig.single img.map { object-fit: contain; padding: 4%; }
.fig-link:hover img:not(.map) { transform: scale(1.04); }
.body { display: flex; flex-direction: column; flex: 1; padding-top: 16px; }
.card h3 { margin: 0; font: 400 21px/1.25 var(--serif); letter-spacing: -.005em; }
.meta { margin: 4px 0 0; color: var(--muted); font-size: 13px; }
.facts { margin: 10px 0 0; font-size: 13.5px; font-variant-numeric: tabular-nums; }
.mods { display: flex; flex-wrap: wrap; gap: 4px 14px; margin: 10px 0 0; padding: 0; list-style: none; color: var(--ink-2); font-size: 12.5px; }
.mod { display: inline-flex; align-items: center; gap: 6px; }
.mod::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: var(--c, var(--img)); }
.mod.hic { --c: var(--hic); } .mod.rna { --c: var(--rna); } .mod.ab { --c: var(--ab); } .mod.atac { --c: var(--atac); }
.mod.img { --c: var(--img); } .mod.xyz { --c: var(--xyz); } .mod.sig { --c: var(--atac); }
.desc { margin: 12px 0 0; color: var(--muted); font-size: 13.5px; line-height: 1.55;
  display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.note { margin: 8px 0 0; color: var(--atac); font-size: 12.5px; }
.actions { display: flex; flex-wrap: wrap; align-items: baseline; gap: 6px 22px; margin-top: auto; padding-top: 14px; }
.open { font-weight: 500; font-size: 14px; }
.download { display: inline-flex; align-items: baseline; gap: 6px; color: var(--ink-2); font-size: 13.5px; }
.download:hover { color: var(--ink); }
.dl-icon { font-weight: 600; }
.dl-size { color: var(--muted); font-size: 12.5px; font-variant-numeric: tabular-nums; }
.open span { display: inline-block; transition: transform .15s ease; }
.open:hover span { transform: translateX(3px); }

.empty, .err { padding: 48px 0; color: var(--muted); text-align: center; }
.empty button { margin-left: 6px; padding: 0; border: 0; background: none; color: var(--accent); font: inherit; cursor: pointer; }
.err { color: var(--hic); }

/* footer */
.foot { margin-top: 32px; padding: 36px 0 56px; border-top: 1px solid var(--rule); color: var(--muted); font-size: 13px; }
.foot-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; }
.foot p { max-width: 36em; margin: 12px 0 0; }
.foot .brand { font-size: 15px; } .foot .brand em { font-size: 17px; }

/* the U-Chrom page */
code, pre { font-family: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace; }
:not(pre) > code { padding: 1px 5px; border-radius: 4px; background: var(--panel); font-size: .88em; }
nav a[aria-current="page"] { color: var(--ink); }
.doc-hero { grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr); }
.eyebrow { margin: 0 0 14px; color: var(--muted); font-size: 12px; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; }
.soon { display: inline-flex; align-items: center; gap: 9px; margin: 0; padding: 7px 14px; border: 1px solid var(--rule-2);
  border-radius: 999px; color: var(--ink-2); font-size: 14px; }
.soon .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--rna); box-shadow: 0 0 0 3px color-mix(in srgb, var(--rna) 25%, transparent); }

.sources { display: flex; flex-direction: column; gap: 8px; margin: 0; padding: 0; list-style: none; }
.sources li { display: flex; flex-direction: column; padding: 12px 16px; border: 1px solid var(--rule); border-radius: 6px; background: var(--paper); }
.sources li b { font-weight: 600; font-size: 14.5px; } .sources li span { color: var(--muted); font-size: 13px; }
.sources li.into { position: relative; margin-top: 18px; border-color: var(--ink); background: var(--ink); color: var(--paper); }
.sources li.into span { color: color-mix(in srgb, var(--paper) 72%, transparent); }
.sources li.into::before { content: "↓"; position: absolute; top: -24px; left: 50%; transform: translateX(-50%); color: var(--muted); }
.sources li.into b { font: 500 19px/1.2 var(--serif); }
.model { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 36px; margin: 0 0 32px; }
.hier { display: flex; flex-direction: column; align-items: stretch; }
.lvl { display: flex; flex-direction: column; padding: 12px 16px; border: 1px solid var(--rule-2); border-radius: 6px; background: var(--panel); }
.lvl b { font: 500 20px/1.2 var(--serif); } .lvl span { color: var(--muted); font-size: 12.5px; }
.lvl.locus { border-color: var(--ab); background: color-mix(in srgb, var(--ab) 10%, var(--panel)); }
.arrow { padding: 4px 0; color: var(--muted); font-size: 13px; text-align: center; }
.axes { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.axis { padding: 16px 18px; border: 1px solid var(--rule); border-radius: 8px; }
.axis h3 { margin: 0 0 12px; font: 400 20px/1.2 var(--serif); }
.axis h3 span { display: block; margin-top: 3px; color: var(--muted); font: 13px var(--sans); }
.axis.linked { border-style: dashed; }
.axis dl { display: grid; grid-template-columns: max-content minmax(0, 1fr); gap: 7px 14px; margin: 0; font-size: 13.5px; }
.axis dt { font-family: "JetBrains Mono", ui-monospace, monospace; font-size: 12.5px; color: var(--ink); }
.axis dd { margin: 0; color: var(--ink-2); }

/* figures of the paper: white plates (the figures are drawn on white), a caption under each */
.paper-fig { margin: 0; }
.paper-fig > a { display: block; padding: 14px; border: 1px solid var(--rule); border-radius: 8px; background: #fff;
  transition: border-color .15s; }
.paper-fig > a:hover { border-color: var(--rule-2); }
.paper-fig img { width: 100%; height: auto; }
.paper-fig figcaption { margin-top: 12px; color: var(--muted); font-size: 13px; line-height: 1.55; }
.paper-fig figcaption b { color: var(--ink-2); font-weight: 600; }
.paper-fig .src { display: block; margin-top: 4px; font-size: 12px; letter-spacing: .02em; }
.paper-fig.wide { margin: 8px 0 40px; }

.doc-section { padding-top: 56px; padding-bottom: 8px; border-top: 1px solid var(--rule); }
.doc-head { max-width: 760px; margin-bottom: 30px; }
.doc-head h2 { margin: 0 0 12px; font: 400 40px/1.1 var(--serif); letter-spacing: -.015em; }
.doc-head p:not(.kind) { margin: 0; color: var(--ink-2); font-size: 16px; }
.bench-split { display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr); gap: 28px; align-items: start; margin-bottom: 28px; }
.principles, .facts-list { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px 28px; margin: 0 0 40px; padding: 0; list-style: none; }
.facts-list.row { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.principles li, .facts-list li { color: var(--ink-2); font-size: 14px; line-height: 1.55; }
.principles b, .facts-list b { display: block; margin-bottom: 4px; color: var(--ink); font-weight: 600; }
.code { margin: 0 0 48px; padding: 20px 22px; overflow-x: auto; border-radius: 8px; background: var(--panel); font-size: 13px; line-height: 1.7; }
.code .c { color: var(--muted); }
.code .k { color: var(--ab); } .code .s { color: var(--hic); }
:root[data-theme="dark"] .paper-fig > a { background: #f4f2ee; border-color: transparent; }
:root[data-theme="dark"] .paper-fig img { filter: brightness(.96); }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .paper-fig > a { background: #f4f2ee; border-color: transparent; }
  :root:not([data-theme="light"]) .paper-fig img { filter: brightness(.96); }
}

@media (max-width: 960px) {
  .doc-hero, .model, .bench-split { grid-template-columns: 1fr; }
  .principles, .facts-list.row { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .hero { grid-template-columns: 1fr; gap: 40px; padding-top: 48px; padding-bottom: 48px; }
  .study { grid-template-columns: 1fr; gap: 24px; }
  .study-head { position: static; }
}
@media (max-width: 600px) {
  .axes, .principles, .facts-list, .facts-list.row { grid-template-columns: 1fr; }
  .doc-head h2 { font-size: 32px; }
  .wrap { padding: 0 16px; }
  nav { gap: 18px; }
  .stats { grid-template-columns: repeat(2, auto); gap: 18px 0; }
  .stats div:nth-child(3) { padding-left: 0; border-left: 0; }
  .stats dd { font-size: 28px; }
  .foot-grid { grid-template-columns: 1fr; gap: 8px; }
  .section-title { font-size: 32px; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; scroll-behavior: auto !important; } }