/* The py_maze documentation site.
 *
 * Every value here comes from DESIGN_LANGUAGE.md in the repository root,
 * which records what it was derived from and the contrast ratio measured
 * for each text and background pair. Change one and change the other. */

/* ---- Tokens ---------------------------------------------------------- */

:root {
  /* light, the default when nothing else is asked for */
  --ground: #ffffff;
  --panel: #f2f2f2;
  --ink: #373d42;
  --ink-muted: #5a6268;
  --rule-color: #6c757d;
  --shadow: rgba(55, 61, 66, 0.16);

  /* the artwork has no rounded corner anywhere in it */
  --radius: 0;
  --rule: 2px;
  --accent-bar: 3px;

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 64px;

  --type-xs: 0.8125rem;
  --type-sm: 0.875rem;
  --type-base: 1rem;
  --type-lg: 1.2rem;
  --type-xl: 1.44rem;
  --type-2xl: 1.728rem;
  --type-3xl: 2.0736rem;

  --face-text: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica,
    Arial, sans-serif;
  --face-code: ui-monospace, SFMono-Regular, "Cascadia Mono", Menlo,
    Consolas, "Liberation Mono", monospace;

  --measure: 76ch;
  --menu-width: 264px;
  --header-height: 56px;
}

@media (prefers-color-scheme: dark) {
  :root[data-theme="auto"] {
    --ground: #22262a;
    --panel: #2b3035;
    --ink: #e6e8ea;
    --ink-muted: #a8b0b6;
    --shadow: rgba(0, 0, 0, 0.5);
  }
}

:root[data-theme="dark"] {
  --ground: #22262a;
  --panel: #2b3035;
  --ink: #e6e8ea;
  --ink-muted: #a8b0b6;
  --shadow: rgba(0, 0, 0, 0.5);
}

/* ---- Ground ---------------------------------------------------------- */

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

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--ground);
  color: var(--ink);
  font-family: var(--face-text);
  font-size: var(--type-base);
  line-height: 1.65;
}

a {
  color: inherit;
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 2px;
}

a:hover {
  background: var(--panel);
}

:focus-visible {
  outline: var(--rule) solid var(--ink);
  outline-offset: 2px;
}

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 40;
  padding: var(--space-3) var(--space-4);
  background: var(--ground);
  border: var(--rule) solid var(--ink);
}

.skip:focus {
  left: var(--space-3);
  top: var(--space-3);
}

/* ---- Header ---------------------------------------------------------- */

.header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 30;
  display: flex;
  align-items: center;
  gap: var(--space-3);
  height: var(--header-height);
  padding: 0 var(--space-4);
  background: var(--ground);
  border-bottom: var(--accent-bar) solid var(--rule-color);
  /* the logo rules its lettering off on a 12 unit pitch; this is that
   * pitch drawn behind the header */
  background-image: repeating-linear-gradient(
    to right,
    var(--panel) 0 1px,
    transparent 1px 12px
  );
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
}

.brand:hover {
  background: none;
  color: var(--ink);
}

/* The mark is artwork rather than lettering, so there is one file per
 * ink: the light theme is shown the dark-ink art and the dark theme the
 * light-ink art. Which one that is has to be settled in CSS, because the
 * theme is a choice the reader can make as well as one the system makes,
 * and the script that records the choice runs after the first paint. */
.brand-art {
  display: none;
  flex: none;
}

.brand-art.on-light {
  display: block;
}

@media (prefers-color-scheme: dark) {
  :root[data-theme="auto"] .brand-art.on-light {
    display: none;
  }

  :root[data-theme="auto"] .brand-art.on-dark {
    display: block;
  }
}

:root[data-theme="dark"] .brand-art.on-light {
  display: none;
}

:root[data-theme="dark"] .brand-art.on-dark {
  display: block;
}

/* every mark is drawn at 40% of its own size: 108px of the 271px
 * wordmark, and 22px of the 54px icon the picture falls back to, which
 * is the mark width the header was laid out around */
.brand-art img {
  display: block;
  width: 108px;
  height: auto;
}

.header-end {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-left: auto;
}

.header-link {
  font-size: var(--type-sm);
  color: var(--ink-muted);
}

.theme-button,
.menu-button {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  min-height: 32px;
  background: var(--ground);
  color: var(--ink);
  border: var(--rule) solid var(--rule-color);
  border-radius: var(--radius);
  font: inherit;
  font-size: var(--type-sm);
  font-weight: 600;
  cursor: pointer;
}

.theme-button:hover,
.menu-button:hover {
  background: var(--panel);
}

.menu-button {
  display: none;
}

.menu-button-bars,
.menu-button-bars::before,
.menu-button-bars::after {
  display: block;
  width: 16px;
  height: 2px;
  background: currentColor;
}

.menu-button-bars {
  position: relative;
}

.menu-button-bars::before,
.menu-button-bars::after {
  content: "";
  position: absolute;
  left: 0;
}

.menu-button-bars::before {
  top: -5px;
}

.menu-button-bars::after {
  top: 5px;
}

/* ---- Shell ----------------------------------------------------------- */

.shell {
  display: grid;
  grid-template-columns: var(--menu-width) minmax(0, 1fr);
  gap: var(--space-6);
  max-width: 1280px;
  margin: 0 auto;
  padding: calc(var(--header-height) + var(--space-6)) var(--space-4)
    var(--space-8);
}

/* ---- Menu ------------------------------------------------------------ */

.menu {
  position: sticky;
  top: calc(var(--header-height) + var(--space-5));
  align-self: start;
  max-height: calc(100vh - var(--header-height) - var(--space-8));
  overflow-y: auto;
  padding-right: var(--space-2);
  border-left: var(--rule) solid var(--panel);
}

.menu-group + .menu-group {
  margin-top: var(--space-2);
}

.menu-group-button {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: var(--space-2) var(--space-3);
  background: none;
  border: 0;
  border-radius: var(--radius);
  color: var(--ink-muted);
  font: inherit;
  font-size: var(--type-xs);
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-align: left;
  cursor: pointer;
}

.menu-group-button:hover {
  background: var(--panel);
  color: var(--ink);
}

.menu-group-caret {
  width: 8px;
  height: 8px;
  border-right: var(--rule) solid currentColor;
  border-bottom: var(--rule) solid currentColor;
  transform: rotate(-45deg);
  transition: transform 120ms ease;
}

.menu-group.is-open .menu-group-caret {
  transform: rotate(45deg);
}

.menu-list {
  display: none;
  margin: 0 0 var(--space-3);
  padding: 0;
  list-style: none;
}

.menu-group.is-open .menu-list {
  display: block;
}

.menu-link {
  display: block;
  padding: var(--space-1) var(--space-3);
  border-left: var(--accent-bar) solid transparent;
  color: var(--ink-muted);
  font-size: var(--type-sm);
  font-weight: 400;
  text-decoration: none;
}

.menu-link:hover {
  background: var(--panel);
  color: var(--ink);
}

/* the page being read is marked by its bar as well as its weight, so the
 * mark does not depend on colour */
.menu-link.is-current {
  border-left-color: var(--rule-color);
  color: var(--ink);
  font-weight: 700;
}

.menu-veil {
  display: none;
}

/* ---- Content --------------------------------------------------------- */

.content {
  min-width: 0;
}

.page {
  max-width: var(--measure);
}

.page-title {
  margin: 0;
  font-size: var(--type-2xl);
  line-height: 1.25;
}

.page-summary {
  margin: var(--space-2) 0 var(--space-6);
  padding-left: var(--space-3);
  border-left: var(--accent-bar) solid var(--rule-color);
  color: var(--ink-muted);
}

.page h1 {
  font-size: var(--type-2xl);
  line-height: 1.25;
}

.page h2 {
  margin-top: var(--space-7);
  padding-bottom: var(--space-2);
  border-bottom: var(--rule) solid var(--panel);
  font-size: var(--type-xl);
  line-height: 1.3;
}

.page h3 {
  margin-top: var(--space-6);
  font-size: var(--type-lg);
  line-height: 1.35;
}

.page h4 {
  margin-top: var(--space-5);
  font-size: var(--type-base);
  text-transform: none;
}

.page p,
.page ul,
.page ol {
  margin: var(--space-4) 0;
}

.page li + li {
  margin-top: var(--space-1);
}

.page hr {
  height: var(--rule);
  margin: var(--space-7) 0;
  background: var(--panel);
  border: 0;
}

blockquote {
  margin: var(--space-4) 0;
  padding: var(--space-2) var(--space-4);
  border-left: var(--accent-bar) solid var(--rule-color);
  background: var(--panel);
  color: var(--ink);
}

blockquote > :first-child {
  margin-top: 0;
}

blockquote > :last-child {
  margin-bottom: 0;
}

/* ---- Code and mazes -------------------------------------------------- */

code,
kbd,
samp {
  font-family: var(--face-code);
  font-size: var(--type-sm);
}

:not(pre) > code {
  padding: 1px var(--space-1);
  background: var(--panel);
  border-radius: var(--radius);
}

pre {
  margin: var(--space-4) 0;
  padding: var(--space-4);
  overflow-x: auto;
  background: var(--panel);
  border-left: var(--accent-bar) solid var(--rule-color);
  border-radius: var(--radius);
}

/* a maze is drawn as characters, so the lines are set tight enough that
 * its walls still read as walls */
pre code {
  display: block;
  padding: 0;
  background: none;
  line-height: 1.35;
  white-space: pre;
  tab-size: 4;
}

/* the highlighter runs on the fenced blocks that name a language; the
 * palette is monochrome, so only the comments are set apart */
.highlight .c,
.highlight .c1,
.highlight .cm,
.highlight .cs,
.highlight .cp {
  color: var(--ink-muted);
  font-style: italic;
}

.highlight .k,
.highlight .kn,
.highlight .kd,
.highlight .nb,
.highlight .nf,
.highlight .nc {
  font-weight: 700;
}

.highlight .s,
.highlight .s1,
.highlight .s2,
.highlight .se,
.highlight .sb {
  color: var(--ink-muted);
}

/* ---- Tables ---------------------------------------------------------- */

/* a table fills the measure the paragraphs above and below it use, so
 * the rules under its rows end where their text ends. The scroll a wide
 * table needs is in the narrow-screen block at the foot of this file,
 * where the page is too narrow to give it the measure instead. */
.page table {
  width: 100%;
  margin: var(--space-4) 0;
  border-collapse: collapse;
  font-size: var(--type-sm);
  font-family: var(--face-code);
}

.page th,
.page td {
  padding: var(--space-2) var(--space-3);
  border-bottom: 1px solid var(--rule-color);
  text-align: left;
  vertical-align: top;
}

.page thead th {
  border-bottom: var(--rule) solid var(--rule-color);
  font-weight: 700;
  white-space: nowrap;
}

.page tbody tr:nth-child(even) {
  background: var(--panel);
}

/* ---- Cards, used on the overview ------------------------------------- */

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: var(--space-4);
  margin: var(--space-5) 0;
  padding: 0;
  list-style: none;
}

.cards li {
  margin: 0;
  padding: var(--space-4);
  background: var(--panel);
  border-left: var(--accent-bar) solid var(--rule-color);
}

.cards a {
  font-size: var(--type-lg);
}

.cards p {
  margin: var(--space-2) 0 0;
  color: var(--ink-muted);
  font-size: var(--type-sm);
}

/* ---- Footer ---------------------------------------------------------- */

.footer {
  max-width: var(--measure);
  margin-top: var(--space-8);
  padding-top: var(--space-4);
  border-top: var(--rule) solid var(--panel);
  color: var(--ink-muted);
  font-size: var(--type-sm);
}

.footer p {
  margin: var(--space-1) 0;
}

/* ---- Narrow screens -------------------------------------------------- */

@media (max-width: 900px) {
  .menu-button {
    display: inline-flex;
  }

  /* the picture has already fallen back to the square icon at this
   * width, so the box it is drawn in follows it down */
  .brand-art img {
    width: 22px;
  }

  .shell {
    grid-template-columns: minmax(0, 1fr);
    gap: 0;
  }

  .menu {
    position: fixed;
    z-index: 25;
    top: var(--header-height);
    left: 0;
    bottom: 0;
    width: min(320px, 86vw);
    max-height: none;
    padding: var(--space-4) var(--space-3);
    overflow-y: auto;
    background: var(--ground);
    border-left: 0;
    border-right: var(--accent-bar) solid var(--rule-color);
    transform: translateX(-102%);
    transition: transform 140ms ease;
  }

  .menu.is-open {
    transform: translateX(0);
  }

  .menu-veil {
    display: block;
    position: fixed;
    z-index: 20;
    inset: var(--header-height) 0 0 0;
    background: var(--shadow);
  }

  .menu-veil[hidden] {
    display: none;
  }

  /* no wrapper needed, and none available: the Markdown a page is
   * written in emits a bare <table>. A cell can hold a name too long to
   * break - collectible_overlay(collectibles) is 33 characters of the
   * monospace face, wider than a 360px phone leaves the page - so below
   * the drawer breakpoint the table becomes its own scrolling block and
   * the header scrolls with the rows it names, rather than taking the
   * whole page sideways with it. Above this width the rule higher up
   * applies and the table fills the measure. */
  .page table {
    display: block;
    width: fit-content;
    max-width: 100%;
    overflow-x: auto;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition-duration: 0.01ms !important;
  }
}