/* A quiet field guide: paper, ink, and one accent (prefs.css) as the wayfinding
   color. The header, footer and reading column are the shared page frame. */
:root {
  color-scheme: light;
  --paper: #f7f7f6;
  --surface: #efeeec;
  --raised: #fcfcfb;
  --ink: #1d1c1a;
  --muted: #5f5b56;
  --soft: #6b6660;
  --line: #dddad5;
  --line-strong: #b9b4ad;
  --code: #efeeec;
  --code-key: #754779;
  --code-string: #32633c;
  --code-number: #8b492e;
  --code-comment: #66615b;
  --code-tag: #315e8e;
  --scrim: rgb(14 14 15 / 38%);
  --shadow: 0 20px 80px rgb(20 18 16 / 16%);
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: "Cascadia Code", "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --header: 4.5rem; /* the sticky search bar: 3rem field + 0.75rem above and below */
  --bg: var(--paper);
  --text: var(--ink);
  --raise: var(--surface);
  --body-size: 1.075rem;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --paper: #0e0e0f;
    --surface: #18181a;
    --raised: #1f1f22;
    --ink: #ece4da;
    --muted: #a39d96;
    --soft: #938d86;
    --line: #2a2a2d;
    --line-strong: #4a4744;
    --code: #18181a;
    --code-key: #d9aedb;
    --code-string: #afc99a;
    --code-number: #e6b197;
    --code-comment: #a39d96;
    --code-tag: #a4c6e5;
    --scrim: rgb(0 0 0 / 65%);
    --shadow: 0 20px 80px rgb(0 0 0 / 40%);
  }
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --paper: #0e0e0f;
  --surface: #18181a;
  --raised: #1f1f22;
  --ink: #ece4da;
  --muted: #a39d96;
  --soft: #938d86;
  --line: #2a2a2d;
  --line-strong: #4a4744;
  --code: #18181a;
  --code-key: #d9aedb;
  --code-string: #afc99a;
  --code-number: #e6b197;
  --code-comment: #a39d96;
  --code-tag: #a4c6e5;
  --scrim: rgb(0 0 0 / 65%);
  --shadow: 0 20px 80px rgb(0 0 0 / 40%);
}
*, *::before, *::after { box-sizing: border-box; }
html { background: var(--paper); scroll-padding-top: calc(var(--header) + 1.5rem); -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
::selection { background: var(--selection); color: var(--ink); }
a { color: inherit; text-underline-offset: .2em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
:where(.workspace, dialog) a:hover { color: var(--accent); }
button, input { font: inherit; color: inherit; }
button, summary { -webkit-tap-highlight-color: transparent; }
button { cursor: pointer; }
button:disabled { cursor: default; }
button, a, summary { touch-action: manipulation; }
:focus-visible { outline: 2px solid var(--mark); outline-offset: 3px; border-radius: 2px; }
button { border-radius: 0; }
[hidden] { display: none !important; }
.icon { width: 1.25rem; height: 1.25rem; flex: 0 0 auto; fill: none; stroke: currentColor; stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; vertical-align: middle; }
.icon.small { width: 1rem; height: 1rem; }
.icon-definitions { position: absolute; width: 0; height: 0; overflow: hidden; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
.js-only { display: none !important; }
.js .js-only { display: revert !important; }
.skip-link { position: fixed; z-index: 20; inset-block-start: .75rem; inset-inline-start: 1rem; padding: .75rem 1rem; background: var(--ink); color: var(--paper); transform: translateY(-180%); border-radius: .3rem; }
.skip-link:focus { transform: translateY(0); }
.eyebrow { font: .75rem/1.5 var(--mono); letter-spacing: .09em; text-transform: uppercase; color: var(--muted); margin: 0; }
.version { font: .75rem/1.4 var(--mono); color: var(--muted); white-space: nowrap; }
kbd { font: .6875rem/1.4 var(--mono); }

/* page-frame:begin — byte-identical in sites/holmhq.com/site.css,
   sites/holmhq.com/docs/styles.css and internal/publicpage/page.css; go test
   ./sites enforces it. Every page shares this column, header and footer, so
   nothing shifts between pages. */
:root { --measure: 38rem; --gutter: 1rem; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 1.0625rem/1.6 var(--sans);
  overflow-wrap: break-word;
}
.wrap { width: 100%; max-width: calc(var(--measure) + 2 * var(--gutter)); margin-inline: auto; padding-inline: var(--gutter); }

/* Header: brand on the left; nav and settings on the right, nav below on
   phones. With script, prefs.css folds the nav into More (and one Menu on
   phones) on the same line. The settings slot has a fixed size, so every
   header is the same. */
.site-header { border-bottom: 1px solid var(--line); }
.site-header .wrap { display: flex; flex-wrap: wrap; align-items: center; gap: 0.25rem 1rem; padding-block: 0.75rem; }
.brand { display: inline-flex; color: var(--text); padding-block: 0.5rem; margin-inline-end: auto; }
.brand-mark { display: block; width: 3.75rem; height: auto; }
.site-nav { order: 3; flex-basis: 100%; display: flex; flex-wrap: wrap; gap: 0 1.25rem; }
.site-nav a { color: var(--muted); text-decoration: none; padding-block: 0.5rem; }
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--text); }

.site-footer { border-top: 1px solid var(--line); color: var(--muted); font-size: 0.9375rem; }
.site-footer .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 0.5rem 1.5rem; padding-block: 1.5rem 2.5rem; }
.site-footer nav { display: flex; flex-wrap: wrap; gap: 0 1.25rem; }
.site-footer a { color: var(--muted); padding-block: 0.375rem; display: inline-block; }
.site-footer a:hover { color: var(--text); }

@media (min-width: 48rem) {
  :root { --gutter: 2rem; }
  body { font-size: 1.125rem; }
  .site-nav { order: 0; flex-basis: auto; }
  .site-header .settings { margin-inline-start: 0.5rem; }
}
/* page-frame:end */

/* search-bar:begin — byte-identical in sites/holmhq.com/site.css and
   sites/holmhq.com/docs/styles.css; go test ./sites enforces it. Pages with
   search (FAQ, docs) open with this bar straight under the header, so the
   field sits in the same place on each. It sticks once the header scrolls
   away; the page script sets data-stuck to draw the rule beneath it. */
.search-bar { position: sticky; inset-block-start: 0; z-index: 20; background: var(--bg); }
.search-bar[hidden] { display: none; }
.search-bar[data-stuck] { box-shadow: 0 1px 0 var(--line); }
.search-bar > .wrap { display: flex; flex-wrap: wrap; align-items: center; gap: 0 0.5rem; padding-block: 0.75rem; }
.search-field { position: relative; flex: 1; min-width: 0; }
.search-input {
  display: block; width: 100%; height: 3rem; margin: 0; padding: 0 2.75rem;
  border: 1px solid var(--line); border-radius: 0.625rem;
  background: var(--raise); color: var(--text);
  font: 1rem/1 var(--sans); text-align: start;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  -webkit-appearance: none; appearance: none;
}
button.search-input { color: var(--muted); cursor: pointer; }
.search-input::placeholder { color: var(--muted); opacity: 1; }
.search-input:hover { border-color: var(--mark); }
.search-input:focus-visible { outline: none; border-color: var(--mark); background: var(--bg); box-shadow: 0 0 0 3px var(--accent-soft); }
.search-input::-webkit-search-cancel-button { -webkit-appearance: none; appearance: none; display: none; }
.search-icon {
  position: absolute; inset-inline-start: 0.875rem; top: 50%; width: 1.25rem; height: 1.25rem; margin-top: -0.625rem;
  fill: none; stroke: var(--muted); stroke-width: 1.75; stroke-linecap: round; pointer-events: none;
}
.search-key {
  position: absolute; inset-inline-end: 0.75rem; top: 50%; transform: translateY(-50%);
  min-width: 1.5rem; padding: 0.125rem 0.375rem; border: 1px solid var(--line); border-radius: 0.25rem;
  background: var(--bg); color: var(--muted); font: 0.75rem/1.2 var(--mono); text-align: center; pointer-events: none;
}
.search-input:focus ~ .search-key, input.search-input:not(:placeholder-shown) ~ .search-key { display: none; }
@media (hover: none) { .search-key { display: none; } }
/* search-bar:end */

/* The guide's bar adds the chapters button (narrow screens) and a reading
   progress line. --header is its height; anchors and the side columns clear it. */
.bar-button { display: flex; align-items: center; justify-content: center; gap: .625rem; height: 3rem; min-width: 3rem; padding-inline: .75rem; border: 1px solid var(--line); border-radius: .625rem; background: var(--raise); color: var(--muted); font-size: 1rem; line-height: 1; }
.bar-button:hover { border-color: var(--mark); color: var(--text); }
.chapters-launch { flex: none; }
.chapters-launch > span { display: none; }
.icon-button { display: inline-flex; justify-content: center; align-items: center; min-width: 2.75rem; min-height: 2.75rem; padding: .5rem; border: 0; background: transparent; border-radius: .375rem; color: var(--muted); }
.icon-button:hover { background: var(--surface); color: var(--ink); }
.reading-track { position: absolute; inset: auto 0 -1px; height: 2px; overflow: hidden; pointer-events: none; }
#reading-progress { height: 100%; background: var(--accent); transform: scaleX(0); transform-origin: left; opacity: .8; }
.workspace { min-width: 0; }
.js .sidebar, .js .context-rail { display: none !important; }
#main { min-width: 0; padding-block-start: 2.25rem; }
#main:focus-visible { outline-offset: -4px; }
#article { min-width: 0; padding-block-end: 1rem; }

/* The reading surface. */
.article-header { margin-block-end: 2.5rem; }
.article-meta { display: flex; flex-wrap: wrap; align-items: center; gap: .65rem 1.1rem; margin-block-end: 1.4rem; }
.article-meta .eyebrow { color: var(--accent); }
.reading-time { color: var(--muted); font: .75rem/1.5 var(--sans); }
.reading-time::before { content: ""; display: inline-block; width: 3px; height: 3px; border-radius: 50%; background: var(--muted); margin: 0 .625rem .15rem 0; }
h1, h2, h3, h4, h5, h6 { overflow-wrap: break-word; }
h1 { font: 650 clamp(2.1rem, 5vw, 2.75rem)/1.12 var(--sans); letter-spacing: -.04em; margin: 0 0 1.125rem; text-wrap: balance; }
.start-title { font-size: clamp(2.75rem, 7vw, 4rem); line-height: 1.035; letter-spacing: -.055em; margin-block-end: 1.5rem; }
.start-title em { font-weight: 400; color: var(--accent); }
.article-description { font-size: 1.1rem; line-height: 1.7; margin: 0; max-width: 56ch; color: var(--muted); text-wrap: pretty; }
.article-utility { display: flex; flex-wrap: wrap; gap: .5rem 1.2rem; align-items: center; margin-block-start: 1.5rem; }
.text-button { display: inline-flex; align-items: center; justify-content: center; gap: .45rem; min-height: 2.75rem; background: transparent; border: 0; color: var(--muted); font-size: .75rem; padding: .4rem 0; text-decoration: none; }
.text-button:hover { color: var(--accent); text-decoration: underline; }
.article-utility a { font-size: .75rem; min-height: 2.75rem; display: inline-flex; align-items: center; }
.prose { font-size: var(--body-size); line-height: 1.83; overflow-wrap: break-word; }
.prose > :first-child { margin-block-start: 0; }
.prose p { margin: 1.25rem 0; }
.prose strong { font-weight: 600; }
.prose a { color: var(--accent); text-decoration-color: var(--line-strong); }
.prose a:hover { text-decoration-color: currentColor; }
.prose ul, .prose ol { padding-inline-start: 1.45rem; margin: 1.4rem 0; }
.prose li { padding-inline-start: .3rem; margin-block: .45rem; }
.prose li::marker { color: var(--accent); font-size: .9em; }
.prose :not(pre) > code { font: .82em/1.5 var(--mono); color: var(--accent); background: var(--surface); border: 1px solid var(--line); border-radius: .2rem; padding: .12em .3em; overflow-wrap: anywhere; box-decoration-break: clone; -webkit-box-decoration-break: clone; }
.prose h2, .prose h3, .prose h4 { margin: 3.25rem 0 1rem; line-height: 1.25; letter-spacing: -.025em; text-wrap: balance; scroll-margin-top: calc(var(--header) + 1.5rem); }
.prose h2 { font: 650 clamp(1.7rem, 3.5vw, 2.05rem)/1.25 var(--sans); }
.prose h3 { font-size: 1.35rem; font-weight: 600; }
.prose h4 { font-size: 1.15rem; font-weight: 600; }
.heading-line { display: flex; align-items: baseline; gap: .5rem; }
.heading-line > span { min-width: 0; }
.heading-link { flex: 0 0 auto; display: inline-flex; align-items: center; justify-content: center; width: 2.5rem; height: 2.5rem; border: 0; background: transparent; color: var(--muted); border-radius: .25rem; align-self: center; }
.heading-link:hover { color: var(--accent); background: var(--surface); }
.prose hr { border: 0; border-block-start: 1px solid var(--line); margin-block: 2.5rem; }
.prose blockquote { margin: 1.5rem 0; border-inline-start: 2px solid var(--accent); padding: .5rem 1.25rem; color: var(--muted); }
.definition { margin: 1.75rem 0; padding-block-end: 1.5rem; border-block-end: 1px solid var(--line); scroll-margin-top: calc(var(--header) + 1.5rem); }
.definition dt { font: 650 1.55rem/1.3 var(--sans); margin-block-end: .5rem; }
.definition dd { margin: 0; }
.table-scroll { max-width: 100%; overflow: auto; margin-block: 1.75rem; border: 1px solid var(--line); border-radius: .25rem; }
.prose table { border-collapse: collapse; min-width: 100%; text-align: start; font-size: .9em; }
.prose th, .prose td { padding: .7rem 1rem; border-block-end: 1px solid var(--line); vertical-align: top; min-width: 9rem; }
.prose th { background: var(--surface); font-weight: 600; }
.prose tr:last-child td { border-block-end: 0; }
.code-block { min-width: 0; margin: 1.6rem 0 2rem; border: 1px solid var(--line); border-radius: .375rem; background: var(--code); overflow: hidden; font-size: 1rem; }
.code-bar { display: flex; align-items: center; justify-content: space-between; gap: 1rem; min-height: 2.875rem; padding-inline: 1rem .375rem; border-block-end: 1px solid var(--line); }
.code-language { color: var(--muted); font: .75rem/1.4 var(--mono); letter-spacing: .025em; }
.copy-code { min-width: 5.25rem; min-height: 2.75rem; padding: .4rem .625rem; display: inline-flex; justify-content: center; align-items: center; gap: .4rem; border: 0; border-radius: .25rem; background: transparent; color: var(--muted); font-size: .75rem; }
.copy-code:hover { background: var(--accent-soft); color: var(--accent); }
.prose pre { margin: 0; padding: 1.125rem 1.25rem 1.375rem; overflow: auto; overscroll-behavior-inline: contain; scrollbar-width: thin; tab-size: 2; font: .875rem/1.8 var(--mono); }
.prose pre:focus-visible { outline-offset: -3px; }
.prose pre code { display: block; min-width: max-content; font: inherit; color: var(--ink); white-space: pre; }
.syntax-key { color: var(--code-key); }
.syntax-string { color: var(--code-string); }
.syntax-number { color: var(--code-number); }
.syntax-comment { color: var(--code-comment); }
.syntax-tag { color: var(--code-tag); }

/* Orientation is a little story, not a wall of reference text. */
.start-prose .intro { font-size: 1.2rem; line-height: 1.75; margin-block-end: 1.75rem; }
.mental-model { display: grid; grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr); gap: .5rem; align-items: stretch; margin-block: 2rem 2.25rem; }
.model-part { min-width: 0; display: flex; flex-direction: column; gap: .45rem; text-decoration: none; border: 1px solid var(--line-strong); border-radius: .3rem; padding: 1.125rem .9rem; background: var(--surface); }
.model-part .icon { color: var(--accent); margin-block-end: .5rem; width: 1.5rem; height: 1.5rem; }
.model-part strong { font: 650 1.35rem/1.25 var(--sans); letter-spacing: -.025em; }
.model-part span { color: var(--muted); font-size: .75rem; line-height: 1.55; }
.model-part:hover { border-color: var(--accent); background: var(--accent-soft); }
.model-plus { align-self: center; font: 650 1.25rem var(--sans); color: var(--muted); }
.start-prose .story-points { list-style: none; padding: 0; margin-block: 1.75rem; counter-reset: story; }
.start-prose .story-points li { position: relative; padding: 0 0 1.4rem 2.375rem; margin: 0; counter-increment: story; }
.story-points li::before { content: "0" counter(story); position: absolute; inset: .25rem auto auto 0; color: var(--accent); font: .75rem/1.8 var(--mono); }
.story-points li strong { display: block; margin-block-end: .15rem; }
.boundary-note { margin-block: 2rem !important; padding: 1.2rem 1.375rem; border-inline-start: 2px solid var(--line-strong); background: var(--surface); font-size: .9em; color: var(--muted); }
.boundary-note strong { color: var(--ink); }
.boundary-note a { display: inline; }
.journeys { margin-block: 3.5rem 1rem; }
.section-caption { display: flex; flex-wrap: wrap; justify-content: space-between; gap: .5rem; align-items: baseline; margin-block-end: 1rem; }
.section-caption h2 { font: 650 1.8rem/1.3 var(--sans); margin: 0; letter-spacing: -.035em; }
.section-caption > span { font: .6875rem/1.5 var(--mono); color: var(--muted); }
.journey-link { display: grid; grid-template-columns: 1.5rem minmax(0, 1fr) auto; align-items: center; gap: .75rem; padding: 1.4rem 0; border-block-start: 1px solid var(--line); text-decoration: none; }
.journey-number { font: .6875rem/1.6 var(--mono); color: var(--muted); align-self: start; padding-block-start: .375rem; }
.journey-name { display: block; font: 650 1.35rem/1.3 var(--sans); letter-spacing: -.02em; margin-block-end: .375rem; }
.journey-description { display: block; color: var(--muted); font-size: .8125rem; line-height: 1.6; }
.journey-link > .icon { color: var(--accent); }
.journey-link:hover .journey-name { text-decoration: underline; text-underline-offset: .2em; }
.path-banner { background: var(--surface); border: 1px solid var(--line); border-radius: .3rem; padding: 0 1rem; margin: -1rem 0 2rem; font-size: .85rem; }
.path-banner summary { min-height: 3.25rem; display: flex; flex-wrap: wrap; align-items: center; gap: .5rem; cursor: pointer; list-style: none; }
.path-banner summary::-webkit-details-marker { display: none; }
.path-banner summary .icon { margin-inline-start: auto; }
.path-step { font: .625rem/1.5 var(--mono); text-transform: uppercase; letter-spacing: .04em; color: var(--accent); }
.path-banner ol { padding-inline-start: 1.5rem; }
.path-banner li { padding-block: .35rem; color: var(--muted); }
.path-banner [aria-current="step"] { color: var(--accent); font-weight: 600; }
.path-banner .exit-path { display: inline-flex; align-items: center; min-height: 2.75rem; margin-block-end: .5rem; font-size: .75rem; color: var(--muted); }
.mobile-toc { margin: -.5rem 0 2rem; border-block: 1px solid var(--line); }
.mobile-toc summary { display: flex; align-items: center; justify-content: space-between; min-height: 3.25rem; list-style: none; cursor: pointer; color: var(--muted); font-size: .8125rem; }
.mobile-toc summary::-webkit-details-marker { display: none; }
.mobile-toc[open] summary .icon { transform: rotate(180deg); }
.mobile-toc nav { max-height: 21rem; overflow: auto; padding-block-end: .75rem; }
.mobile-toc a { display: flex; align-items: center; min-height: 2.75rem; font-size: .8125rem; text-decoration: none; padding: .5rem .5rem .5rem 1rem; border-inline-start: 1px solid var(--line); }
.mobile-toc a:hover { color: var(--accent); border-color: var(--accent); }
.related-reading { margin-block: 3rem 2rem; border-block-start: 1px solid var(--line); padding-block-start: 1.4rem; }
.related-reading nav { display: flex; flex-wrap: wrap; gap: 0 1.5rem; margin-block-start: .5rem; }
.related-reading a { min-height: 2.75rem; display: inline-flex; align-items: center; gap: .4rem; color: var(--accent); text-decoration: none; font-size: .8125rem; }
.related-reading a:hover { text-decoration: underline; }
.page-turns { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 1rem; margin-block-start: 2rem; }
.page-turn { min-width: 0; display: flex; flex-direction: column; align-items: flex-start; gap: .6rem; padding-block: 1.25rem; text-decoration: none; border-block-start: 1px solid var(--line-strong); }
.page-turn.next { text-align: end; align-items: flex-end; grid-column: 2; }
.page-turn .turn-direction { color: var(--muted); display: inline-flex; align-items: center; gap: .5rem; font: .6875rem/1.5 var(--mono); }
.page-turn .turn-title { font: 650 1.2rem/1.4 var(--sans); letter-spacing: -.02em; overflow-wrap: break-word; }
.page-turn:hover { border-color: var(--accent); }
.reader-end { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 0 1.25rem; padding-block: 1.5rem 2.5rem; font: .6875rem/1.6 var(--mono); color: var(--muted); }
.reader-end > a { min-height: 2.75rem; display: inline-flex; align-items: center; text-decoration: none; }
.reader-end .text-button { font: inherit; }

/* Navigation, including the mobile drawer. */
.chapter-navigation { min-height: 0; }
.nav-group { margin-block-end: 1rem; }
.nav-group summary { display: flex; align-items: center; min-height: 2.75rem; gap: .625rem; padding-inline: .75rem; cursor: pointer; list-style: none; font-size: .75rem; font-weight: 600; color: var(--muted); }
.nav-group summary::-webkit-details-marker { display: none; }
.nav-group summary .nav-count { margin-inline-start: auto; font: .625rem var(--mono); color: var(--muted); }
.nav-group summary .icon { width: .875rem; height: .875rem; }
.nav-group[open] summary .icon { transform: rotate(180deg); }
.nav-group ul { list-style: none; margin: .25rem 0; padding: 0; }
.nav-link { display: flex; align-items: center; min-height: 2.5rem; padding: .6rem .75rem; gap: .6rem; border-inline-start: 2px solid transparent; text-decoration: none; font-size: .8125rem; line-height: 1.45; color: var(--muted); }
.nav-link:hover { background: var(--surface); color: var(--ink); }
.nav-link[aria-current="page"] { background: var(--accent-soft); color: var(--accent); border-inline-start-color: var(--accent); font-weight: 600; }
.index-nav-link { margin-block: .5rem 1.5rem; border-block-end: 1px solid var(--line); padding-block-end: 1rem; }
.index-nav-link a { display: flex; align-items: center; gap: .75rem; min-height: 2.75rem; padding-inline: .75rem; text-decoration: none; font-size: .8125rem; color: var(--muted); }
.index-nav-link a[aria-current="page"] { color: var(--accent); font-weight: 600; }
.index-nav-link span { font: .6875rem var(--mono); color: var(--accent); }

/* Native dialogs provide keyboard and modal focus behavior. */
dialog { color: var(--ink); background: var(--paper); border: 1px solid var(--line-strong); border-radius: .75rem; padding: 0; width: min(44rem, calc(100% - 1.5rem)); max-height: calc(100dvh - 2rem); box-shadow: var(--shadow); overscroll-behavior: contain; }
dialog::backdrop { background: var(--scrim); }
body:has(dialog[open]) { overflow: hidden; }
.dialog-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: .75rem; padding: 1.5rem; }
.dialog-heading .eyebrow { margin-block-end: .5rem; }
.dialog-heading .version { margin-inline-start: .5rem; letter-spacing: 0; text-transform: none; }
.dialog-heading h2 { font: 650 1.75rem/1.15 var(--sans); letter-spacing: -.035em; margin: 0; }
.dialog-heading .icon-button { margin: -.5rem -.5rem 0 0; }
.nav-dialog { margin: 0 auto 0 0; width: min(25rem, 100%); height: 100dvh; max-height: none; border-radius: 0; border-block: 0; border-inline-start: 0; }
.nav-dialog[open] { display: flex; flex-direction: column; }
.nav-dialog .chapter-navigation { overflow: auto; padding-inline: .75rem; overscroll-behavior: contain; flex: 1; }
.nav-dialog .nav-link { min-height: 2.75rem; font-size: .9rem; padding-inline: 1rem; }
.nav-dialog summary { font-size: .8125rem; }
.dialog-bottom-link { margin: 0 1.5rem; padding-block: 1rem calc(1rem + env(safe-area-inset-bottom)); border-block-start: 1px solid var(--line); display: flex; align-items: center; justify-content: space-between; gap: .5rem; text-decoration: none; color: var(--muted); font-size: .75rem; }
.search-dialog { margin-block: max(1rem, 10dvh) auto; }
.search-dialog[open] { display: flex; flex-direction: column; }
.search-input-row { display: flex; align-items: center; gap: .75rem; padding: .75rem 1rem .75rem 1.25rem; border-block-end: 1px solid var(--line); flex-shrink: 0; }
.search-input-row > .icon { color: var(--accent); }
#search-input { min-width: 0; width: 100%; height: 2.75rem; border: 0; background: transparent; font-size: 1rem; outline-offset: 0; }
#search-input::placeholder { color: var(--soft); opacity: 1; }
#search-input:focus-visible { outline: 0; }
.search-input-row:focus-within { box-shadow: inset 0 -2px var(--accent); }
#search-input::-webkit-search-cancel-button { cursor: pointer; }
.search-results-area { min-height: 13rem; max-height: 60dvh; overflow-y: auto; padding: .75rem; overscroll-behavior: contain; }
#search-status { padding: .6rem .75rem .9rem; }
#search-results { margin: 0; padding: 0; list-style: none; }
.search-result { display: block; padding: .9rem .8rem; border-radius: .3rem; text-decoration: none; border: 1px solid transparent; }
.search-result:hover, .search-result[aria-selected="true"] { background: var(--surface); border-color: var(--line); color: var(--ink); }
.search-result[aria-selected="true"] { border-inline-start: 2px solid var(--accent); }
.result-trail { display: block; color: var(--muted); font-size: .6875rem; margin-block-end: .25rem; }
.result-title { display: block; font-size: .975rem; line-height: 1.45; font-weight: 600; }
.result-snippet { display: block; margin-block-start: .375rem; font-size: .8125rem; line-height: 1.65; color: var(--muted); overflow-wrap: anywhere; }
mark { color: var(--accent); background: var(--selection); border-radius: 2px; padding-inline: 1px; }
.search-footer { display: flex; flex-wrap: wrap; justify-content: space-between; gap: .5rem; border-block-start: 1px solid var(--line); padding: .75rem 1.25rem; font-size: .625rem; color: var(--muted); flex-shrink: 0; }
.search-footer kbd { display: inline-flex; justify-content: center; min-width: 1.2rem; padding: .05rem .2rem; margin-inline-end: .2rem; border: 1px solid var(--line-strong); border-radius: .15rem; font-size: .625rem; }
.empty-search { padding: 1rem .8rem 2rem; }
.empty-search h3 { font: 650 1.75rem/1.3 var(--sans); margin: 0 0 .75rem; }
.empty-search p { color: var(--muted); font-size: .875rem; }
.empty-search button { min-height: 2.75rem; padding: .4rem .8rem; margin: .25rem .5rem .25rem 0; background: var(--surface); border: 1px solid var(--line); border-radius: .25rem; color: var(--accent); font-size: .8rem; }
.toast { position: fixed; z-index: 10; inset-inline: 1.25rem; inset-block-end: calc(1.25rem + env(safe-area-inset-bottom)); margin-inline: auto; width: fit-content; max-width: calc(100% - 2.5rem); border-radius: .35rem; padding: .7rem 1rem; background: var(--ink); color: var(--paper); box-shadow: var(--shadow); font-size: .8125rem; pointer-events: none; opacity: 0; }
.toast:not(:empty) { opacity: 1; }
.toast.has-action { display: flex; align-items: center; gap: .75rem; pointer-events: auto; }
.toast-dismiss { display: inline-flex; align-items: center; justify-content: center; min-width: 2.75rem; min-height: 2.75rem; border: 0; background: transparent; color: inherit; margin: -.5rem -.5rem -.5rem 0; }

/* A real index, with letter-sized landmarks. */
.index-filter { display: block; font-size: .8125rem; color: var(--muted); margin-block: 1.5rem; }
.index-filter input { display: block; margin-block-start: .5rem; width: 100%; min-height: 3rem; padding: .7rem 1rem; border: 1px solid var(--line-strong); background: transparent; border-radius: .25rem; font-size: 1rem; }
.alphabet { display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); gap: .25rem; padding-block: .25rem 1.25rem; border-block-end: 1px solid var(--line); }
.alphabet a { min-width: 1.5rem; flex: 1; min-height: 2.75rem; display: inline-flex; align-items: center; justify-content: center; font: .75rem var(--mono); border-radius: .2rem; text-decoration: none; color: var(--accent); }
.alphabet a:hover { background: var(--accent-soft); }
.alphabet .letter-empty { opacity: .4; color: var(--muted); pointer-events: none; }
.index-group { display: grid; grid-template-columns: 2.5rem minmax(0, 1fr); gap: 1rem; margin-block: 2rem; scroll-margin-top: calc(var(--header) + 1.5rem); }
.index-group h2 { font: 650 2.5rem/1.25 var(--sans); color: var(--accent); margin: 0; }
.index-group ul { list-style: none; padding: 0; margin: 0; }
.index-entry { display: block; text-decoration: none; padding: .7rem 0; border-block-end: 1px solid var(--line); }
.index-entry > span { display: block; font-size: .95rem; line-height: 1.5; overflow-wrap: anywhere; }
.index-entry > small { display: block; color: var(--muted); font-size: .6875rem; line-height: 1.5; margin-block-start: .25rem; }
.index-entry:hover > span { text-decoration: underline; }
.index-empty { color: var(--muted); padding-block: 2rem; }
.loading-message, .error-message { color: var(--muted); font-size: .95rem; }
.error-actions { display: flex; flex-wrap: wrap; gap: 1rem; align-items: center; margin-block: 1.5rem; }
.primary-button { display: inline-flex; align-items: center; justify-content: center; gap: .75rem; min-height: 2.875rem; padding: .625rem 1rem; background: var(--accent); color: var(--paper); border: 1px solid var(--accent); border-radius: .25rem; text-decoration: none; font-size: .875rem; }
.primary-button:hover { background: var(--ink); color: var(--paper); border-color: var(--ink); }

@media (min-width: 35rem) {
  .chapters-launch > span { display: inline; }
  .mental-model { gap: 1.1rem; }
  .model-part { padding: 1.35rem 1.5rem; }
  .model-part strong { font-size: 1.6rem; }
  .model-part span { font-size: .8125rem; }
}
@media (min-width: 48rem) {
  #main { padding-block-start: 3rem; }
  .alphabet { display: flex; flex-wrap: nowrap; gap: .125rem; }
  .prose pre { font-size: .875rem; padding: 1.35rem 1.5rem 1.6rem; }
  .start-prose .intro { font-size: 1.25rem; }
}
/* Wide screens: the reading column stays exactly where every other page puts
   it; the chapters and this page's sections sit in the margins either side. */
@media (min-width: 75rem) {
  .workspace { display: grid; grid-template-columns: minmax(0, 1fr) calc(var(--measure) + 2 * var(--gutter)) minmax(0, 1fr); align-items: start; }
  #main { grid-column: 2; grid-row: 1; }
  .chapters-launch, .mobile-toc { display: none; }
  .js .sidebar { display: flex !important; flex-direction: column; gap: 1rem; grid-column: 1; grid-row: 1; justify-self: end; width: 14.5rem; position: sticky; inset-block-start: var(--header); height: calc(100dvh - var(--header)); padding-block-start: 3rem; }
  .sidebar-intro { padding-inline: .75rem; display: flex; align-items: center; gap: .75rem; justify-content: space-between; }
  .sidebar-intro .eyebrow { font-size: .6875rem; letter-spacing: .04em; }
  .sidebar .chapter-navigation { flex: 1; overflow: auto; scrollbar-width: thin; scrollbar-color: var(--line-strong) transparent; overscroll-behavior: contain; padding-block: .25rem; }
  .sidebar-footer { padding: .9rem .75rem 1.25rem; border-block-start: 1px solid var(--line); }
  .sidebar-footer > a { display: flex; align-items: center; gap: .5rem; min-height: 2.75rem; text-decoration: none; color: var(--muted); font-size: .6875rem; }
  .sidebar-footer > span { font-size: .625rem; color: var(--muted); }
  .sidebar-footer a > .icon:last-child { margin-inline-start: auto; }
  .js .context-rail { display: block !important; grid-column: 3; grid-row: 1; justify-self: start; width: 12rem; position: sticky; inset-block-start: var(--header); padding-block-start: 3.15rem; }
  .context-rail > .eyebrow { margin-block-end: .9rem; font-size: .6875rem; }
  .rail-toc { max-height: calc(100dvh - var(--header) - 15rem); overflow-y: auto; scrollbar-width: thin; }
  .rail-toc a { display: block; min-height: 2rem; padding: .4rem 0 .4rem 1rem; border-inline-start: 1px solid var(--line); text-decoration: none; color: var(--muted); font-size: .75rem; line-height: 1.5; }
  .rail-toc a[aria-current="location"] { color: var(--accent); border-inline-start: 2px solid var(--accent); font-weight: 600; }
  .rail-toc a.subordinate { padding-inline-start: 1.75rem; font-size: .6875rem; }
  .rail-toc a:hover { color: var(--accent); }
  .rail-note { margin-block-start: 2rem; padding-block-start: 1rem; border-block-start: 1px solid var(--line); font-size: .6875rem; line-height: 1.8; color: var(--muted); }
  .rail-note a { color: var(--accent); }
  .rail-note p { margin: .5rem 0; }
  .rail-shortcuts { display: flex; flex-direction: column; gap: .25rem; }
  .rail-shortcuts a { display: inline-flex; align-items: center; justify-content: space-between; gap: .5rem; min-height: 2.75rem; font-size: .75rem; text-decoration: none; color: var(--muted); }
  .rail-shortcuts a:hover { color: var(--accent); }
}
@media (max-width: 34.99rem) {
  :root { --body-size: 1.025rem; }
  .article-header { margin-block-end: 2rem; }
  .article-meta { gap: .5rem; }
  .article-description { font-size: 1rem; }
  .article-utility { margin-block-start: 1rem; }
  .reader-end > a { width: 100%; }
  .search-dialog { margin-block: .625rem auto; max-height: calc(100dvh - 1.25rem); }
  .search-results-area { max-height: 65dvh; }
  .search-input-row { padding-inline: .75rem .375rem; gap: .5rem; }
  .search-footer { padding: .75rem 1rem; }
  .search-footer > span:first-child { display: none; }
  .index-group { grid-template-columns: 1.75rem minmax(0, 1fr); gap: .75rem; }
  .index-group h2 { font-size: 2rem; }
  .page-turn .turn-title { font-size: 1.075rem; }
}
@media (prefers-reduced-motion: no-preference) {
  a, button, .model-part { transition: border-color 130ms ease; }
  dialog[open] { animation: arrive 130ms ease-out; }
  .toast { transition: opacity 130ms ease; }
  @keyframes arrive { from { opacity: 0; transform: translateY(5px); } to { opacity: 1; transform: none; } }
}
@media (forced-colors: active) {
  button, .code-block, .model-part, .path-banner, dialog { border: 1px solid ButtonText; }
  [aria-current], [aria-pressed="true"], [aria-selected="true"] { outline: 2px solid Highlight; outline-offset: -2px; }
  mark { color: HighlightText; background: Highlight; }
}
@media print {
  .site-header, .site-footer, .docs-bar, .sidebar, .context-rail, .reader-end, .mobile-toc, .article-utility, .heading-link, .copy-code, .page-turns, .toast, .skip-link { display: none !important; }
  body { color: #111; background: white; }
  .workspace { display: block; }
  #main { padding: 0; }
  .prose pre { white-space: pre-wrap; overflow-wrap: anywhere; }
  .prose pre code { min-width: 0; white-space: pre-wrap; }
  .code-block { break-inside: avoid; }
}