/* The site's one stylesheet: palette, type, layout, code. Light by default, dark where the system
   asks for it or the switch chose it. */

@font-face { font-family: "Inter"; font-style: normal; font-weight: 100 900; font-display: swap; src: url("fonts/InterVariable.woff2") format("woff2"); }
@font-face { font-family: "Inter"; font-style: italic; font-weight: 100 900; font-display: swap; src: url("fonts/InterVariable-Italic.woff2") format("woff2"); }
/* Code needs three faces of the mono: regular, bold for types, italic for comments. */
@font-face { font-family: "JetBrains Mono"; font-style: normal; font-weight: 400; font-display: swap; src: url("fonts/JetBrainsMono-Regular.woff2") format("woff2"); }
@font-face { font-family: "JetBrains Mono"; font-style: normal; font-weight: 700; font-display: swap; src: url("fonts/JetBrainsMono-Bold.woff2") format("woff2"); }
@font-face { font-family: "JetBrains Mono"; font-style: italic; font-weight: 400; font-display: swap; src: url("fonts/JetBrainsMono-Italic.woff2") format("woff2"); }

:root {
  --bg: #ffffff;
  --text: #16181d;
  --muted: #535a69;
  --line: #e1e4e9;
  --surface: #f4f5f7;
  --accent: #6440c4;
  --literal: #8a5a00;

  --sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --space: 12px;
  --bar: 48px;
  color-scheme: light;
}

:root[data-theme="dark"] {
  --bg: #111317;
  --text: #e7e9ee;
  --muted: #a3aab6;
  --line: #2b2f37;
  --surface: #181b21;
  --accent: #b29aff;
  --literal: #d9a54a;
  color-scheme: dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #111317;
    --text: #e7e9ee;
    --muted: #a3aab6;
    --line: #2b2f37;
    --surface: #181b21;
    --accent: #b29aff;
    --literal: #d9a54a;
    color-scheme: dark;
  }
}

*, *::before, *::after { box-sizing: border-box; border-radius: 0; }
[hidden] { display: none !important; }

html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.55 var(--sans);
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.pending { color: var(--muted); }

h1, h2, h3, h4 { line-height: 1.25; margin: calc(var(--space) * 2) 0 var(--space); }
h1 { font-size: 28px; letter-spacing: -0.02em; }
h2 { font-size: 21px; letter-spacing: -0.01em; }
h3 { font-size: 17px; }
p, ul, ol { margin: 0 0 var(--space); }

code, pre { font-family: var(--mono); font-size: 13.5px; }
:not(pre) > code { background: var(--surface); padding: 0 4px; overflow-wrap: anywhere; }
pre {
  background: var(--surface);
  margin: 0 0 var(--space);
  padding: var(--space);
  overflow-x: auto;
  line-height: 1.5;
}
pre code { background: none; padding: 0; }

/* Code: keywords in the accent, types bold, literals ochre, comments muted and italic. */
.kw { color: var(--accent); }
.ty { font-weight: 700; }
.str, .num { color: var(--literal); }
.com { color: var(--muted); font-style: italic; }

table { border-collapse: collapse; margin: 0 0 var(--space); display: block; max-width: 100%; overflow-x: auto; }
th, td { border-bottom: 1px solid var(--line); padding: 4px 8px; text-align: left; vertical-align: top; }

/* The header: a toolbar. */
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: calc(var(--space) * 1.5);
  min-height: var(--bar);
  padding: 0 calc(var(--space) * 1.5);
  background: var(--bg);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: baseline; gap: 8px; }
.wordmark { color: var(--text); font-weight: 700; font-size: 19px; letter-spacing: -0.03em; }
.wordmark:hover { text-decoration: none; }
.version, select.version {
  color: var(--muted);
  font: 12px var(--sans);
  border: 1px solid var(--line);
  background: var(--bg);
  padding: 1px 6px;
}
.areas { display: flex; gap: var(--space); flex: 1; overflow-x: auto; white-space: nowrap; }
.areas a, .areas .pending { color: var(--text); }
.areas .pending { color: var(--muted); }
.areas a.current { color: var(--accent); }
.search input {
  width: 180px;
  font: 14px var(--sans);
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--line);
  padding: 4px 8px;
}
.search input:disabled { opacity: 0.6; }
.search { position: relative; }
.search-results {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  z-index: 20;
  width: min(480px, calc(100vw - 2 * var(--space)));
  max-height: 60vh;
  overflow-y: auto;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--bg);
  border: 1px solid var(--line);
}
.search-results li { border-bottom: 1px solid var(--line); }
.search-results li:last-child { border-bottom: none; }
.search-results a { display: block; padding: 8px var(--space); color: var(--text); }
.search-results a:hover, .search-results li[aria-selected="true"] a { background: var(--surface); text-decoration: none; }
.search-results .title { font-weight: 600; }
.search-results .area { margin-left: 8px; color: var(--muted); font-size: 12px; }
.search-results .excerpt { display: block; color: var(--muted); font-size: 13px; }
.search-results mark { background: none; color: var(--accent); font-weight: 600; }
.search-results .none { padding: 8px var(--space); color: var(--muted); }
.theme-toggle {
  font: 16px var(--sans);
  color: var(--text);
  background: none;
  border: 1px solid var(--line);
  padding: 2px 8px;
  cursor: pointer;
}
.github { color: var(--text); }

/* The footer. */
.footer {
  display: flex;
  flex-wrap: wrap;
  gap: calc(var(--space) * 1.5);
  padding: calc(var(--space) * 2) calc(var(--space) * 1.5);
  margin-top: calc(var(--space) * 3);
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}
.footer a, .footer .pending { color: var(--muted); }

/* Two columns for text, three for reference. */
.columns {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: calc(var(--space) * 2);
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 calc(var(--space) * 1.5);
}
body.reference .columns { grid-template-columns: 240px minmax(0, 1fr) 200px; }

.sidebar, .on-this-page {
  position: sticky;
  top: var(--bar);
  align-self: start;
  max-height: calc(100vh - var(--bar));
  overflow-y: auto;
  padding: calc(var(--space) * 1.5) 0;
  font-size: 14px;
}
.sidebar-bar { display: none; }
.sidebar-box, .on-this-page ul { list-style: none; margin: 0; padding: 0; }
.sidebar-box li, .on-this-page li { margin: 0 0 6px; }
.sidebar-box a, .sidebar-box .pending { color: var(--text); }
.sidebar-box a.current { color: var(--accent); font-weight: 600; }
.on-this-page a { color: var(--muted); }
.on-this-page .level-3 { padding-left: var(--space); }
.aside-title { color: var(--muted); font-size: 12px; text-transform: uppercase; letter-spacing: 0.04em; }

.text { min-width: 0; overflow-wrap: break-word; padding: calc(var(--space) * 0.5) 0 0; }
.text p, .text ul, .text ol, .text blockquote { max-width: 68ch; }

/* Notes in a text: a block quote. */
.text blockquote {
  margin: 0 0 var(--space);
  padding: var(--space);
  background: var(--surface);
  border-left: 3px solid var(--accent);
}
.text blockquote p:last-child { margin-bottom: 0; }

/* What a program printed: right under its code, set apart by a rule instead of a surface. */
pre.output { background: none; border-left: 2px solid var(--line); margin-top: calc(var(--space) * -0.5); }

/* A snippet that is not a working program says so above it; one that must fail is marked at its edge. */
.snippet-note { margin: 0; padding: 2px var(--space); font-size: 13px; color: var(--muted); background: var(--surface); border-bottom: 1px solid var(--line); }
.snippet-note.fails { color: var(--text); border-left: 3px solid var(--muted); }
.snippet-note.fails::before { content: "✗ "; }
pre.fails { border-left: 3px solid var(--muted); }
/* What the compiler says about it, right under the snippet, like a program's output. */
pre.diagnostic { background: none; border-left: 3px solid var(--muted); margin-top: calc(var(--space) * -0.5); }

/* The reference: a member's head as written, its text under it, one member set off from the next. */
pre.signature { margin: 0 0 calc(var(--space) * 0.5); }
.member { border-top: 1px solid var(--line); padding-top: calc(var(--space) * 0.75); margin-top: calc(var(--space) * 0.75); }
.member:target { border-top-color: var(--accent); }
.conforms { color: var(--muted); font-size: 14px; }
.listing { padding-left: 0; list-style: none; }
.listing li, .listed { margin: 0 0 calc(var(--space) * 0.25); }
.listed .kind, .summary { color: var(--muted); }

/* The way on through the Book: the chapter before and the one after. */
.pager {
  display: flex;
  justify-content: space-between;
  gap: var(--space);
  margin: calc(var(--space) * 2) 0;
  padding-top: var(--space);
  border-top: 1px solid var(--line);
}
.pager .next { margin-left: auto; }

/* The start page. */
.home-main { max-width: 1200px; margin: 0 auto; padding: calc(var(--space) * 3) calc(var(--space) * 1.5) 0; }
.hero { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); gap: calc(var(--space) * 3); align-items: start; }
.hero h1 { font-size: 36px; letter-spacing: -0.03em; margin-top: 0; }
.lead { font-size: 17px; color: var(--muted); max-width: 52ch; }
.actions { display: flex; gap: var(--space); margin-top: calc(var(--space) * 2); }
.button {
  display: inline-block;
  padding: 8px 16px;
  border: 1px solid var(--accent);
  color: var(--accent);
  font-weight: 600;
}
.button.primary { background: var(--accent); color: var(--bg); }
.button:hover { text-decoration: none; }
span.button { border-color: var(--line); color: var(--muted); }
span.button.primary { background: var(--surface); color: var(--muted); }
.program { margin: 0; }
.claims, .entries {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: calc(var(--space) * 2);
  margin-top: calc(var(--space) * 3);
}
.claims { border-top: 1px solid var(--line); padding-top: calc(var(--space) * 2); }
.claim h2, .entry h2 { font-size: 17px; margin-top: 0; }
.claim p, .entry p { color: var(--muted); }

/* "On this page" goes first. */
@media (max-width: 1149px) {
  body.reference .columns { grid-template-columns: 240px minmax(0, 1fr); }
  .on-this-page { display: none; }
}

/* Narrow: the navigation becomes a bar above the text, opened into a box of its own. */
@media (max-width: 899px) {
  .topbar { flex-wrap: wrap; padding: 6px var(--space); gap: var(--space); }
  .areas { order: 3; flex-basis: 100%; }
  .search input { width: 120px; }
  .search { position: static; }
  .search-results { top: 100%; left: var(--space); right: var(--space); width: auto; }

  .columns, body.reference .columns { display: block; padding: 0 var(--space); }
  .sidebar {
    position: sticky;
    top: var(--bar);
    z-index: 5;
    max-height: none;
    overflow: visible;
    padding: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
  }
  .sidebar-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--space);
    padding: 8px 0;
  }
  .where { color: var(--muted); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .contents-toggle {
    font: 600 14px var(--sans);
    color: var(--accent);
    background: none;
    border: 1px solid var(--line);
    padding: 2px 10px;
    cursor: pointer;
  }
  .sidebar-box { max-height: 50vh; overflow-y: auto; padding-bottom: var(--space); }
  html.js .sidebar:not(.open) .sidebar-box { display: none; }

  .hero, .claims, .entries { grid-template-columns: minmax(0, 1fr); }
  .hero h1 { font-size: 28px; }
}