/* The Safari Ride book. The prose keeps a reading measure, and code, tables and
   diagrams may run wider into the right margin. A narrow window takes the chapter
   list out of the way, and a printed page drops whatever only a screen can use. */
:root {
  color-scheme: light dark;
  --paper: #fbfaf6;
  --ink: #23221f;
  --quiet: #736e64;
  --rule: #e3e0d7;
  --accent: #8a4a1c;
  --shade: #f3f1ea;
  --draft: #fbefc6;
  --draft-ink: #5e4706;
  --code-literal: #4d6b33;
  --code-type: #2f5d7c;
  --prose: 'Iowan Old Style', Charter, 'Bitstream Charter', 'Sitka Text', Cambria, Georgia, serif;
  --plain: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --mono: ui-monospace, 'SF Mono', Menlo, Consolas, 'DejaVu Sans Mono', monospace;
  --measure: 39rem;
  --wide: 52rem;
  font-size: 18px;
}

@media screen and (prefers-color-scheme: dark) {
  :root {
    --paper: #1b1a18;
    --ink: #e4e1d8;
    --quiet: #9c978b;
    --rule: #38352f;
    --accent: #dba56d;
    --shade: #26241f;
    --draft: #443612;
    --draft-ink: #f0d98f;
    --code-literal: #a9c08a;
    --code-type: #8fb8d4;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--prose);
  line-height: 1.6;
  text-rendering: optimizeLegibility;
}

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 0.15em; }

/* The page */

body.chapter { display: grid; grid-template-columns: 15rem minmax(0, 1fr); }
body.chapter main { padding: 3rem 3rem 4rem 4rem; }
body.front main { max-width: calc(var(--measure) + 4rem); margin: 0 auto; padding: 4rem 2rem; }

article > * { max-width: var(--measure); }
article > table { max-width: var(--wide); }
article > figure.diagram { max-width: var(--measure); }

/* A code listing matches the prose, and widens only for the lines that need it. */
article > figure.listing { width: fit-content; min-width: min(100%, var(--measure)); max-width: var(--wide); }

.book-bar { display: none; }

/* The bar across the top of every page: the way back to the site, and the way
   to the code. It spans both columns of a chapter. */

.top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 0.45rem 1.5rem;
  border-bottom: 1px solid var(--rule);
  font: 0.72rem/1.4 var(--plain);
}
body.chapter > .top-bar { grid-column: 1 / -1; }
/* The same pill every app page has, from site/web/shared/home.js. */
.home-link { padding: 3px 8px; border-radius: 4px; background: rgba(24, 24, 24, 0.72); color: #fff; text-decoration: none; }
.repo-link { color: var(--quiet); text-decoration: none; }
.repo-link:hover { color: var(--accent); }

/* Headings */

h1, h2, h3 { line-height: 1.2; font-weight: 600; scroll-margin-top: 1.5rem; text-wrap: balance; }
h1 { font-size: 2.1rem; letter-spacing: -0.01em; margin: 0 0 1.5rem; }
h2 { font-size: 1.4rem; margin: 2.8rem 0 0.8rem; }
h3 { font-size: 1.1rem; margin: 2rem 0 0.6rem; }

/* A section links to itself, for a reader to copy. It keeps out of the way until
   the heading is pointed at, and a touch screen shows it faintly. */
.section-link { margin-left: 0.2em; color: var(--quiet); font-size: 0.75em; font-weight: 400; text-decoration: none; opacity: 0; }
h2:hover .section-link, .section-link:focus { opacity: 1; }
.section-link:hover { color: var(--accent); }
@media (hover: none) { .section-link { opacity: 0.5; } }

/* A chapter named in the prose is a cross-reference, so it reads as text with a
   faint dotted line under it until it is pointed at. */
.chapter-link { color: inherit; text-decoration: underline dotted var(--quiet); text-decoration-thickness: 1px; }
.chapter-link:hover, .chapter-link:focus { color: var(--accent); text-decoration-color: currentColor; }

.chapter-number {
  margin: 0 0 0.3rem;
  color: var(--quiet);
  font: 0.75rem/1.4 var(--plain);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

p { margin: 0 0 1rem; }
ul, ol { padding-left: 1.4rem; }
li { margin: 0.25rem 0; }

/* Code */

code { font-family: var(--mono); font-size: 0.82em; }
:not(pre) > code { background: var(--shade); border-radius: 2px; padding: 0.05em 0.12em; }

/* A line too long for the column wraps, so no block scrolls and none hides its end. */

pre {
  margin: 0 0 1.6rem;
  padding: 0.75rem 1rem;
  background: var(--shade);
  border-radius: 4px;
  font-size: 0.78rem;
  line-height: 1.5;
  tab-size: 4;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}
pre code { font-size: inherit; }

/* color_roc.shale marks Roc's code. A few quiet colors are enough to read by. */

.syn-comment { color: var(--quiet); }
.syn-string, .syn-number { color: var(--code-literal); }
.syn-keyword { color: var(--accent); }
.syn-type { color: var(--code-type); }
.syn-name { font-weight: 600; }

/* A listing's title sits inside the block it names, small and quiet. */

figure { margin: 1.6rem 0; }
figure.listing { background: var(--shade); border-radius: 4px; }
figure.listing figcaption { padding: 0.5rem 1rem 0; color: var(--quiet); font: 0.66rem/1.4 var(--mono); }
figure.listing pre { margin: 0; padding: 0.3rem 1rem 0.75rem; background: none; }

/* A figure's caption reads as a caption: under it, in the plain face. */

figure.widget figcaption, figure.diagram figcaption { margin-top: 0.5rem; color: var(--quiet); font: 0.76rem/1.45 var(--plain); }
figcaption code { background: none; padding: 0; }

/* Diagrams come from Graphviz. Its colours are attributes, so these rules win, and
   a diagram takes the book's type and follows the page into dark mode. A dashed box
   stands for a family and a bold one is the diagram's subject. */

svg.diagram { display: block; max-width: 100%; height: auto; }
svg.diagram-phone { display: none; }
svg.diagram text { fill: var(--ink); font-family: var(--plain); }
svg.diagram .graph > polygon { fill: none; stroke: none; }
svg.diagram .cluster polygon { fill: none; stroke: var(--rule); }
svg.diagram .cluster text { fill: var(--quiet); font-style: italic; }
svg.diagram .node polygon, svg.diagram .node ellipse { fill: var(--shade); stroke: var(--quiet); }
svg.diagram .node polyline { stroke: var(--quiet); }
svg.diagram .node [stroke-width] { stroke: var(--accent); }
svg.diagram .node [stroke-dasharray] { fill: none; }
svg.diagram .edge path { stroke: var(--quiet); }
svg.diagram .edge polygon { fill: var(--quiet); stroke: var(--quiet); }
svg.diagram .edge text { fill: var(--quiet); }

/* Widgets */

iframe.canvas-app { display: block; width: 100%; border: 0; border-radius: 4px; background: var(--shade); }

/* Tables */

table {
  margin: 0 0 1.6rem;
  border-collapse: collapse;
  font: 0.8rem/1.45 var(--plain);
  font-variant-numeric: tabular-nums;
}
th { text-align: left; border-bottom: 1px solid var(--quiet); }
td { border-bottom: 1px solid var(--rule); }
th, td { padding: 0.35rem 1rem 0.35rem 0; vertical-align: top; }
th:last-child, td:last-child { padding-right: 0; }
/* book.js marks a column of sentences as prose, and it wraps at a reading
   width, about sixty characters a line. */
th.prose, td.prose { width: 30em; }

/* Draft notes stay in sight, and they look like notes rather than the book. */

.draft-note { background: var(--draft); color: var(--draft-ink); font: 0.74rem/1.5 var(--plain); }
span.draft-note { padding: 0.1em 0.3em; border-radius: 3px; -webkit-box-decoration-break: clone; box-decoration-break: clone; }
p.draft-note { padding: 0.5rem 0.8rem; border-radius: 3px; }
.draft-note code { background: none; padding: 0; }
.draft-note::before { content: 'Draft note: '; font-weight: 600; }

/* The chapters beside the page */

.book-nav {
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  padding: 3rem 1rem 2rem 1.5rem;
  border-right: 1px solid var(--rule);
  font: 0.74rem/1.35 var(--plain);
}
.book-nav a { display: block; padding: 0.22rem 0; color: var(--quiet); text-decoration: none; }
.book-nav a:hover { color: var(--accent); }
.book-nav .book-name { margin-bottom: 1rem; color: var(--ink); font: 600 1rem/1.3 var(--prose); }
.book-nav ol { list-style: none; margin: 0; padding: 0; }
.book-nav li { margin: 0; }
.book-nav .here > a { color: var(--ink); font-weight: 600; }
.book-nav .sections { margin: 0.1rem 0 0.5rem; padding-left: 1.7em; }
.number { display: inline-block; width: 1.7em; color: var(--quiet); font-variant-numeric: tabular-nums; font-weight: 400; text-indent: 0; }
a:has(> .number) { padding-left: 1.7em; text-indent: -1.7em; }

.book-nav li.part { margin-top: 0.9rem; color: var(--accent); font-weight: 700; }
.book-nav li.category { margin-top: 0.4rem; color: var(--quiet); font-style: italic; }

/* The table of contents */

ol.contents { max-width: 34rem; margin: 0 auto; padding: 0; list-style: none; font: 0.9rem/1.45 var(--plain); }
ol.contents > li { margin: 0 0 1rem; padding-left: 1.6rem; }
ol.contents > li.part { margin: 2rem 0 0.8rem; padding: 0 0 0.3rem; border-bottom: 1px solid var(--rule); color: var(--accent); font-size: 1.15rem; font-weight: 700; }
ol.contents > li.category { margin: 1.2rem 0 0.6rem; padding-left: 0.8rem; color: var(--quiet); font-size: 0.95rem; font-style: italic; }
ol.contents > li > a { display: block; color: var(--ink); font-weight: 600; text-decoration: none; }
ol.contents a:hover { color: var(--accent); }
ol.contents .sections { margin: 0.15rem 0 0; padding-left: 2.2em; list-style: none; }
ol.contents .sections li { margin: 0.1rem 0; }
ol.contents .sections a { color: var(--quiet); text-decoration: none; }

/* Previous and next */

.turn-page {
  display: flex;
  justify-content: space-between;
  gap: 2rem;
  max-width: var(--measure);
  margin-top: 3.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
  font: 0.85rem/1.3 var(--plain);
}
.turn-page a { text-decoration: none; }
.turn-page a[rel='next'] { text-align: right; }
.turn-page small { display: block; color: var(--quiet); font-size: 0.72rem; }

/* A narrow window puts the chapter first. A bar at the top leads to the book's
   front and down to the chapter list, which follows the page. */

@media (max-width: 60rem) {
  body.chapter { display: flex; flex-direction: column; }
  body.chapter main { padding: 1rem 1rem 2rem; }
  body.front main { padding: 2rem 1rem; }
  .top-bar { padding-inline: 1rem; }
  .book-nav { order: 2; position: static; height: auto; padding: 1rem; border-right: 0; border-top: 1px solid var(--rule); }
  .book-nav a { padding-block: 0.35rem; }
  .book-bar {
    display: flex;
    justify-content: space-between;
    max-width: none;
    margin: 0 0 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--rule);
    font: 0.8rem/1.4 var(--plain);
  }
  .book-bar a { text-decoration: none; }
}

/* A phone: the diagrams drawn for it, a widget as wide as the window, and code and
   tables that wrap, so nothing on the page scrolls sideways. */

@media (max-width: 45rem) {
  :root { font-size: 17px; }
  svg.diagram-phone { display: block; }
  svg.diagram-wide { display: none; }
  figure.widget { margin-inline: -1rem; }
  figure.widget figcaption { padding-inline: 1rem; }
  iframe.canvas-app { border-radius: 0; }
  figure.listing { margin-inline: -0.5rem; }
  figure.listing figcaption { padding-inline: 0.6rem; }
  figure.listing pre { padding-inline: 0.6rem; font-size: 0.72rem; tab-size: 2; }
  article > table { width: 100%; font-size: 0.76rem; }
  th, td { padding-right: 0.6rem; }
  th.prose, td.prose { width: auto; }
}

/* A printed book: black on white, with no navigation and nothing split that can
   stay whole. */

@media print {
  :root { font-size: 11pt; --paper: #fff; --ink: #000; --quiet: #444; --accent: #000; }
  body.chapter { display: block; }
  body.chapter main, body.front main { max-width: none; padding: 0; }
  .book-nav, .book-bar, .turn-page, .section-link { display: none; }
  article > *, article > table, article > figure.diagram, article > figure.listing { max-width: 100%; }
  h1, h2, h3 { break-after: avoid; }
  figure, tr { break-inside: avoid; }
  a { text-decoration: none; }
}