/* gxdoc default stylesheet.
   Manuals: a sand rail with the manual's numbered contents, a reading column,
   margin notes on wide screens. Piazzolla for text, Fira Mono for code.
   Colours meet WCAG AA in light and dark: text 4.5:1, link underlines and
   focus rings 3:1. Surfaces step 5 OKLCH lightness points apart. */

@font-face {
  font-family: "Piazzolla";
  src: url("gxdoc-fonts/piazzolla.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Piazzolla";
  src: url("gxdoc-fonts/piazzolla-italic.woff2") format("woff2");
  font-weight: 100 900;
  font-style: italic;
  font-display: swap;
}

@font-face {
  font-family: "Fira Mono";
  src: url("gxdoc-fonts/fira-mono.woff2") format("woff2");
  font-weight: 400;
  font-display: swap;
}

@font-face {
  font-family: "Fira Mono";
  src: url("gxdoc-fonts/fira-mono-medium.woff2") format("woff2");
  font-weight: 500 700;
  font-display: swap;
}

/* ----------------------------------------------------------------- Tokens */
:root {
  color-scheme: light dark;

  --serif: "Piazzolla", Georgia, serif;
  --mono: "Fira Mono", ui-monospace, monospace;
  --text: 1.1875rem;
  --leading: 1.5;
  --code-scale: 0.8em;
  --measure: 40rem;
  --rail: 17rem;
  --margin: 13rem;
  --gap: 2.75rem;
  --pad: clamp(1rem, 4vw, 1.5rem);

  --paper: light-dark(#fffdfa, #17130f);
  --ink: light-dark(#231c17, #ede4da);
  --muted: light-dark(#6d6158, #b3a596);
  --rule: light-dark(#ecdfd2, #352b23);
  --accent: light-dark(#3e3a9e, #b3aefc);
  --underline: light-dark(#8d87da, #6662b8);
  --mark: light-dark(#e2e0fb, #39366e);
  --number: light-dark(#956b46, #c9a07a);

  --rail-paper: light-dark(#f6ebe1, #251d18);
  --rail-ink: light-dark(#392e25, #c8b7a7);
  --rail-strong: light-dark(#1e1611, #ffffff);
  --rail-faint: light-dark(#7c604a, #a08a76);
  --rail-rule: light-dark(#e5d1be, #3a2e25);
  --current-paper: light-dark(#ebd9c7, #342921);
  --current-number: light-dark(#6e543f, #c9a07a);

  --code-paper: light-dark(#f8f2ec, #211b16);
  --code-ink: light-dark(#3a3592, #c3bffc);
  --note-paper: light-dark(#f8f0e7, #221b15);
  --note-rule: light-dark(#e0c4a8, #4a3a2c);
}

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

html {
  text-size-adjust: 100%;
  -webkit-text-size-adjust: 100%;
  scroll-padding-block-start: 1.5rem;
  accent-color: var(--accent);
  scrollbar-color: var(--rule) transparent;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: var(--text);
  line-height: var(--leading);
  font-kerning: normal;
  font-optical-sizing: auto;
  font-variant-ligatures: common-ligatures;
  font-variant-numeric: oldstyle-nums proportional-nums;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  hanging-punctuation: first;
}

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

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 1px;
}

a {
  color: var(--accent);
  text-decoration-line: underline;
  text-decoration-color: var(--underline);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.2em;
  text-decoration-skip-ink: auto;
}

a:hover {
  text-decoration-color: currentColor;
}

img {
  max-inline-size: 100%;
  block-size: auto;
}

/* The first link on every page skips the navigation. */
body > a:first-child {
  position: absolute;
  inset: 0.5rem auto auto 0.5rem;
  z-index: 10;
  padding: 0.5rem 1rem;
  background: var(--ink);
  color: var(--paper);
  translate: 0 -200%;
}

body > a:first-child:focus {
  translate: none;
}

/* ------------------------------------------------------------------ Frame */
body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  min-block-size: 100dvh;
  align-content: start;
}

nav ol, nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

/* Manual rail: sequence links, then the manual's numbered contents. */
nav[aria-label="Manual"] {
  background: var(--rail-paper);
  color: var(--rail-ink);
  font-size: 1rem;
  line-height: 1.35;
  font-variant-numeric: lining-nums tabular-nums;
}

nav[aria-label="Manual"] a {
  color: inherit;
  text-decoration: none;
}

nav[aria-label="Manual"] a:hover {
  color: var(--rail-strong);
}

nav[aria-label="Manual"] > ul {
  display: flex;
  gap: 0.25rem 1.25rem;
  padding: 0.25rem var(--pad);
  border-block-end: 1px solid var(--rail-rule);
  font-variant-caps: all-small-caps;
  letter-spacing: 0.07em;
}

nav[aria-label="Manual"] > ul a {
  display: inline-flex;
  align-items: center;
  min-block-size: 2.75rem;
  min-inline-size: 1.75rem;
}

nav[aria-label="Manual"] summary {
  display: flex;
  align-items: center;
  min-block-size: 2.75rem;
  padding: 0.25rem var(--pad);
  cursor: pointer;
  list-style: none;
  font-variant-caps: all-small-caps;
  letter-spacing: 0.07em;
}

nav[aria-label="Manual"] summary::-webkit-details-marker {
  display: none;
}

nav[aria-label="Manual"] summary::after {
  content: "";
  display: inline-block;
  inline-size: 0.38em;
  block-size: 0.38em;
  margin-inline-start: 0.6em;
  border-block-end: 0.1em solid currentColor;
  border-inline-end: 0.1em solid currentColor;
  rotate: 45deg;
  translate: 0 -0.2em;
}

nav[aria-label="Manual"] details[open] > summary::after {
  rotate: 225deg;
  translate: 0 0.05em;
}

nav[aria-label="Manual"] details > p {
  margin: 0.25rem var(--pad) 0.75rem;
  font-size: 1.0625rem;
  line-height: 1.25;
}

nav[aria-label="Manual"] details > p > a {
  display: block;
}

nav[aria-label="Manual"] details > ol {
  padding: 0 var(--pad) 2rem;
}

/* Numbered entries hang their numbers in a column that widens with depth. */
nav[aria-label="Manual"] li > a {
  display: grid;
  grid-template-columns: var(--num, 1.7em) 1fr;
  column-gap: 0.4em;
  padding-block: 0.22rem;
}

nav[aria-label="Manual"] li > a:not(:has(> span)) {
  grid-template-columns: 1fr;
}

nav[aria-label="Manual"] li > a > span {
  color: var(--rail-faint);
}

nav[aria-label="Manual"] ol ol {
  --num: 2.5em;
  margin-inline-start: 1.1em;
  padding-inline-start: 0.6em;
  border-inline-start: 1px solid var(--rail-rule);
}

nav[aria-label="Manual"] ol ol ol {
  --num: 3.3em;
  font-size: 0.9375em;
}

nav[aria-label="Manual"] ol ol ol a {
  padding-block: 0.12rem;
}

/* The current page: an even row one step darker than the rail. */
nav[aria-label="Manual"] [aria-current="page"] {
  margin-inline: -0.5em;
  padding-inline: 0.5em;
  border-radius: 3px;
  background: var(--current-paper);
  color: var(--rail-strong);
  font-weight: 600;
}

nav[aria-label="Manual"] [aria-current="page"] > span {
  color: var(--current-number);
}

/* Wide screens: a fixed rail with its contents always open. */
@media (min-width: 64rem) {
  body {
    grid-template-columns: var(--rail) minmax(0, 1fr);
    background: linear-gradient(to right, var(--rail-paper) var(--rail), var(--paper) 0);
  }

  nav[aria-label="Manual"] {
    position: sticky;
    inset-block-start: 0;
    align-self: start;
    max-block-size: 100dvh;
    overflow-y: auto;
    overscroll-behavior: contain;
    /* Keep keyboard focus clear of the sticky sequence row. */
    scroll-padding-block: 7rem 1rem;
  }

  nav[aria-label="Manual"] > ul {
    position: sticky;
    inset-block-start: 0;
    z-index: 1;
    background: var(--rail-paper);
  }

  nav[aria-label="Manual"] [aria-current="page"] {
    scroll-initial-target: nearest;
  }
}

@supports selector(::details-content) {
  @media (min-width: 64rem) {
    nav[aria-label="Manual"] summary {
      display: none;
    }

    nav[aria-label="Manual"] details::details-content {
      content-visibility: visible;
      display: contents;
    }

    nav[aria-label="Manual"] details > p {
      margin-block-start: 1.25rem;
    }
  }
}

/* ------------------------------------------------------------------- Main */
main {
  min-inline-size: 0;
  padding: 2.5rem var(--pad) 5rem;
  background: var(--paper);
}

main:focus {
  outline: none;
}

main > * {
  max-inline-size: var(--measure);
}

@media (min-width: 64rem) {
  main {
    padding-inline: clamp(2rem, 5vw, 4.5rem);
  }
}

/* Margin notes need room for a second column. */
@media (min-width: 84rem) {
  main {
    padding-inline-end: calc(var(--margin) + var(--gap) + 2rem);
  }

  aside {
    float: inline-end;
    clear: inline-end;
    inline-size: var(--margin);
    margin-inline-end: calc(-1 * (var(--margin) + var(--gap)));
    margin-block: 0.25rem 1rem;
  }
}

@media (min-width: 110rem) {
  main {
    padding-inline-start: clamp(4rem, 8vw, 9rem);
  }
}

aside {
  margin-block: 1.25em;
  padding: 0.75rem 1rem;
  background: var(--note-paper);
  border-inline-start: 1px solid var(--note-rule);
  font-size: 0.875rem;
  line-height: 1.45;
}

aside > :first-child {
  margin-block-start: 0;
}

aside > :last-child {
  margin-block-end: 0;
}

/* ------------------------------------------------------------------- Text */
section {
  scroll-margin-block-start: 1.5rem;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.15;
  text-wrap: balance;
  margin-block: 2.2em 0.55em;
  font-variant-numeric: lining-nums;
}

h1 {
  font-size: clamp(2.125rem, 1.6rem + 2.2vw, 3rem);
  font-weight: 800;
  font-variation-settings: "opsz" 72;
  letter-spacing: -0.02em;
  line-height: 1.08;
  margin-block: 0 0.6em;
}

h2 {
  font-size: 1.5rem;
  font-variation-settings: "opsz" 36;
}

h3 {
  font-size: 1.1875rem;
  font-variation-settings: "opsz" 36;
}

h4 {
  font-size: 1rem;
  font-style: italic;
  font-weight: 400;
}

/* Section numbers written by gxdoc */
:is(h1, h2, h3) > span:first-child {
  margin-inline-end: 0.35em;
  color: var(--number);
  font-weight: 400;
  font-variant-numeric: lining-nums tabular-nums;
}

p, ul, ol, dl, pre, table, blockquote, figure {
  margin-block: 0 1em;
}

p {
  text-wrap: pretty;
}

main :is(ul, ol):not(nav *) {
  padding-inline-start: 1.25em;
}

main li:not(nav *) + li {
  margin-block-start: 0.3em;
}

main li > p {
  margin-block: 0.3em;
}

main li::marker {
  color: var(--muted);
}

strong {
  font-weight: 650;
}

code, kbd, samp, pre {
  font-family: var(--mono);
  font-variant-ligatures: none;
  font-variant-numeric: normal;
  hyphens: manual;
}

:not(pre) > code {
  font-size: var(--code-scale);
  color: var(--code-ink);
  overflow-wrap: anywhere;
}

pre {
  max-inline-size: 100%;
  overflow-x: auto;
  padding: 0.8rem 1rem;
  background: var(--code-paper);
  color: var(--ink);
  font-size: var(--code-scale);
  line-height: 1.55;
  tab-size: 2;
}

pre code {
  font-size: 1em;
  color: inherit;
}

blockquote {
  margin-inline: 0;
  padding-inline-start: 1.25rem;
  border-inline-start: 1px solid var(--rule);
  color: var(--muted);
}

.tip, .warning {
  margin-block: 1.25em;
  padding: 0.75rem 1rem;
  background: var(--note-paper);
  border-inline-start: 1px solid var(--note-rule);
}

:is(.tip, .warning) > :last-child {
  margin-block-end: 0;
}

hr {
  border: 0;
  border-block-start: 1px solid var(--rule);
  margin-block: 2.5rem;
}

/* Tables scroll inside a focusable region rather than widening the page. */
[role="region"]:has(> table) {
  max-inline-size: 100%;
  overflow-x: auto;
  margin-block: 0 1.25em;
}

table {
  border-collapse: collapse;
  font-variant-numeric: lining-nums tabular-nums;
  font-size: 0.9375em;
}

th, td {
  padding: 0.4em 0.9em 0.4em 0;
  text-align: start;
  vertical-align: top;
  border-block-end: 1px solid var(--rule);
}

th {
  font-variant-caps: all-small-caps;
  letter-spacing: 0.06em;
  font-weight: 600;
  border-block-end-color: var(--ink);
}

td > code, th > code {
  white-space: nowrap;
}

[data-align="left"] { text-align: left; }
[data-align="center"] { text-align: center; }
[data-align="right"] { text-align: right; }

/* -------------------------------------------- Contents lists inside pages */
nav[aria-label="Contents"] {
  margin-block: 2.5rem 0;
}

nav[aria-label="Contents"] > ol > li {
  margin-block: 0 1.25rem;
}

nav[aria-label="Contents"] a {
  display: grid;
  grid-template-columns: 1.6em 1fr;
  column-gap: 0.4em;
  text-decoration: none;
}

nav[aria-label="Contents"] a > span {
  color: var(--number);
  font-variant-numeric: lining-nums tabular-nums;
}

nav[aria-label="Contents"] > ol > li > a {
  font-weight: 700;
  font-size: 1.1875rem;
}

nav[aria-label="Contents"] ol ol {
  margin-block-start: 0.2rem;
  margin-inline-start: 2.2em;
}

nav[aria-label="Contents"] ol ol li {
  margin-block: 0.1rem;
}

nav[aria-label="Contents"] ol ol a {
  grid-template-columns: 2.2em 1fr;
}

/* The site's manuals, grouped under small-caps category headings */
nav[aria-label="Manuals"] {
  margin-block: 2.5rem 3rem;
}

nav[aria-label="Manuals"] h2 {
  margin-block: 2rem 0.5rem;
  font-size: 1rem;
  font-variant-caps: all-small-caps;
  letter-spacing: 0.08em;
  color: var(--muted);
}

nav[aria-label="Manuals"] li {
  margin-block: 0 0.75rem;
  color: var(--muted);
  font-size: 1rem;
}

nav[aria-label="Manuals"] li > :is(a, p > a):first-child {
  display: block;
  font-weight: 700;
  font-size: 1.3125rem;
  text-decoration: none;
}

nav[aria-label="Manuals"] li p {
  margin: 0;
}

/* ------------------------------------------------------ Previous and next */
nav[aria-label="Previous and next"] {
  margin-block-start: 4.5rem;
  padding-block-start: 1.25rem;
  border-block-start: 1px solid var(--rule);
}

nav[aria-label="Previous and next"] ul {
  display: flex;
  justify-content: space-between;
  gap: 1.5rem;
}

nav[aria-label="Previous and next"] li:has([rel="next"]) {
  margin-inline-start: auto;
  text-align: end;
}

nav[aria-label="Previous and next"] a {
  display: block;
  text-decoration: none;
  font-size: 1.125rem;
  line-height: 1.3;
}

nav[aria-label="Previous and next"] span {
  display: block;
  color: var(--muted);
  font-size: 0.9375rem;
  font-variant-caps: all-small-caps;
  letter-spacing: 0.08em;
}

/* ---------------------------------------------------------- Small screens */
@media (max-width: 40rem) {
  :root {
    --text: 1.0625rem;
  }

  h2 {
    font-size: 1.3125rem;
  }
}

/* Forced colours drop backgrounds; keep the current page and boxes marked. */
@media (forced-colors: active) {
  nav[aria-label="Manual"] [aria-current="page"] {
    outline: 1px solid CanvasText;
    outline-offset: -1px;
  }

  pre, aside, .tip, .warning {
    border: 1px solid CanvasText;
  }
}

@media print {
  nav {
    display: none;
  }

  body {
    display: block;
    background: none;
  }

  pre {
    white-space: pre-wrap;
  }
}