/* Technopedia site stylesheet.
 *
 * Style per the README: vanilla CSS, artsy, inspired by retro computer
 * science catalogues — serious, Bauhaus-inspired, solid colors and
 * geometric shapes, sometimes dithering. Classes are shared between the
 * injected site chrome (masthead, nav, footer, see build.js) and the
 * rendered page content; no inline styles anywhere.
 */

:root {
  color-scheme: light;

  /* Bauhaus primaries on catalog paper. */
  --paper: #f5f0e6;
  --paper-dim: #ebe3d2;
  --ink: #17130c;
  --red: #ca2c1d;
  --blue: #27519e;
  --green: #2e7d32;
  --yellow: #e6a417;

  /* Sizes. */
  --measure: 46rem; /* content column, ~72 characters */
  --frame: 64rem; /* masthead and footer */
  --gutter: 1.25rem;
  --rule: 2px solid var(--ink);
  --offset-shadow: 7px 7px 0;

  /* Type. */
  --font-body: Georgia, 'Times New Roman', Times, serif;
  --font-header: 'Squada One', Helvetica, Arial, sans-serif;
  --font-display: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, 'Cascadia Mono', Menlo, Consolas, 'Courier New', monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1.05rem;
  line-height: 1.65;
}

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

a { color: inherit; }

a:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 2px;
}

/* Dithered bands: a two-tone checkerboard, the retro-print texture. */
.dither {
  height: 10px;
  background-image: repeating-conic-gradient(var(--ink) 0% 25%, transparent 0% 50%);
  background-size: 6px 6px;
}

/* The logo (masthead brand, home hero, 404): the technopedia.svg wordmark,
 * presented as a framed plate. */
.logo-plate {
  display: block;
  height: auto;
}
.brand .logo-plate { height: 1rem; width: auto; flex: none; }

/* Masthead. */
.masthead { border-bottom: var(--rule); }
.masthead-inner {
  max-width: var(--frame);
  margin: 0 auto;
  padding: 1.1rem var(--gutter) 0.9rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.4rem 1.5rem;
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.6em;
  text-decoration: none;
}
.brand-name {
  font-family: var(--font-header);
  font-weight: 800;
  font-size: 1.35rem;
  color: #480807;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.brand-tagline {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
}
.topic-nav { flex-basis: 100%; }
.topic-nav ul {
  display: flex;
  flex-wrap: wrap;
  margin: 0;
  padding: 0;
  list-style: none;
  border: var(--rule);
}
.topic-link {
  display: block;
  padding: 0.45em 0.9em;
  border-right: var(--rule);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  text-decoration: none;
}
.topic-nav li:last-child .topic-link { border-right: none; }
.topic-link:hover { background: var(--ink); color: var(--paper); }
.topic-link.current { background: var(--red); color: var(--paper); }

/* Page body. */
main.page {
  position: relative;
  max-width: var(--measure);
  margin: 0 auto;
  padding: 2rem var(--gutter) 0;
  counter-reset: section;
}

/* Page-kind stamp, top right. */
.page::before {
  position: absolute;
  top: 1.25rem;
  right: var(--gutter);
  padding: 0.2em 0.6em;
  border: 2px solid var(--red);
  color: var(--red);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  transform: rotate(3deg);
}
.page--topic::before { content: 'Topic'; }
.page--entry::before { content: 'Entry'; }
.page--home::before { content: none; }

main.page h1 {
  margin: 0 0 1.4rem;
  padding-bottom: 0.25em;
  border-bottom: 6px solid var(--ink);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.1rem, 6vw, 3.1rem);
  line-height: 1.05;
  letter-spacing: -0.01em;
  text-transform: uppercase;
}

main.page h2 {
  margin: 2.4rem 0 0.9rem;
  padding-top: 0.45em;
  border-top: var(--rule);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.35rem;
  text-transform: uppercase;
  letter-spacing: 0.01em;
  counter-increment: section;
}
main.page h2::before {
  margin-right: 0.7em;
  color: var(--red);
  font-family: var(--font-mono);
  font-weight: 400;
  content: counter(section, decimal-leading-zero);
}

main.page h3 {
  margin: 1.8rem 0 0.6rem;
  font-family: var(--font-display);
  font-size: 1.05rem;
}
main.page h3::before {
  display: inline-block;
  width: 0.5em;
  height: 0.5em;
  margin-right: 0.5em;
  background: var(--red);
  content: '';
}

main.page p { margin: 0 0 1.1rem; }

main.page a[href^='http']::after {
  content: ' »';
  color: var(--red);
  font-family: var(--font-mono);
}
.autolink-clicker { text-decoration: none; opacity: 0.35; }

main.page ul,
main.page ol { margin: 0 0 1.1rem; padding-left: 1.6rem; }
main.page li { margin: 0.35rem 0; }
main.page li::marker { color: var(--red); }

/* Horizontal rules: dithering. */
main.page hr {
  height: 10px;
  margin: 2.2rem 0;
  border: none;
  background-image: repeating-conic-gradient(var(--ink) 0% 25%, transparent 0% 50%);
  background-size: 6px 6px;
}

/* Categorization tables: solid rules, ink header row. */
main.page table {
  display: block;
  width: 100%;
  margin: 1.6rem 0;
  border-collapse: collapse;
  border: var(--rule);
  overflow-x: auto;
}
main.page th {
  padding: 0.55em 0.8em;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  text-align: left;
}
main.page td {
  padding: 0.6em 0.8em;
  border-bottom: 1px solid var(--ink);
  vertical-align: top;
}
main.page tr:nth-child(even) td { background: var(--paper-dim); }
main.page td:first-child, main.page td[rowspan] + td {
  font-family: var(--font-display);
  font-weight: 700;
}

/* Folded sections: catalog cards with + / − markers. */
main.page details {
  margin: 1.6rem 0;
  border: var(--rule);
  background: var(--paper-dim);
}
main.page summary {
  display: flex;
  align-items: baseline;
  gap: 0.6em;
  padding: 0.5em 0.9em;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
main.page summary::-webkit-details-marker { display: none; }
main.page summary::before {
  color: var(--red);
  font-family: var(--font-mono);
  font-weight: 400;
  content: '+';
}
main.page details[open] summary::before { content: '−'; }
main.page summary:hover { background: var(--ink); color: var(--paper); }
main.page details > *:not(summary) { margin-right: 1rem; margin-left: 1rem; }
main.page details > :last-child { margin-bottom: 1.1rem; }

/* Simulations and figures: framed panels with a solid offset shadow. */
main.page iframe {
  display: block;
  width: 100%;
  min-height: 28rem;
  margin: 1.8rem 0;
  border: var(--rule);
  background: var(--ink);
  box-shadow: var(--offset-shadow) var(--ink);
}
main.page figure { margin: 1.8rem 0; }
main.page figcaption {
  padding-top: 0.4em;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.07em;
}

/* Math: display equations on a tinted panel with a red rule. */
.katex-display {
  margin: 1.5rem 0;
  padding: 0.7em 1em;
  border-left: 4px solid var(--red);
  background: var(--paper-dim);
  overflow-x: auto;
}

/* Code: terminal panels. */
main.page pre {
  margin: 1.4rem 0;
  padding: 1em 1.2em;
  border: var(--rule);
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 0.88rem;
  line-height: 1.5;
  overflow-x: auto;
}
main.page code { font-family: var(--font-mono); font-size: 0.92em; }
main.page pre code { font-size: inherit; }
main.page :not(pre) > code {
  padding: 0.1em 0.3em;
  background: var(--paper-dim);
}

main.page blockquote {
  margin: 1.4rem 0;
  padding: 0.1em 1.2em;
  border-left: 4px solid var(--blue);
}

/* Stub notice for pages the agent has not written yet. */
.stub-note {
  margin: 2rem 0;
  padding: 1em 1.4em;
  border: 2px dashed var(--ink);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

/* Home page. */
.hero { padding: 1.5rem 0 0.5rem; }
.hero-kicker {
  margin: 0 0 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--red);
}
section.hero h1 {
  margin-bottom: 1rem;
  font-family: var(--font-header);
  font-size: clamp(3rem, 9vw, 6rem);
  color: #480807;
  border-bottom: 6px solid #480807;
}
.hero .lede {
  max-width: 38rem;
  font-size: 1.2rem;
}
.hero-mark {
  margin: 2.2rem 0 1rem;
}
.hero-logo {
  display: block;
  height: auto;
  width: min(100%, 68%);
}

.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr));
  gap: 1.4rem;
  margin: 1.6rem 0 1rem;
}
.topic-card {
  display: block;
  padding: 1.1rem 1.2rem 1.2rem;
  border: var(--rule);
  border-top: 8px solid var(--accent, var(--ink));
  text-decoration: none;
  box-shadow: var(--offset-shadow) var(--ink);
  transition: transform 120ms ease, box-shadow 120ms ease, background-color 120ms ease, color 120ms ease;
}
.topic-card:hover {
  background: var(--accent, var(--ink));
  color: var(--paper);
  transform: translate(-3px, -3px);
  border-top: 8px solid color-mix(in srgb, var(--accent), black 30%);
  box-shadow: 10px 10px 0 var(--ink);
}
/* Keep every line readable on the accent background; ink text on the light
 * yellow, paper text on the darker accents. */
.topic-card:hover .topic-card-index { color: var(--paper); }
.topic-card.accent-yellow:hover,
.topic-card.accent-yellow:hover .topic-card-index { color: var(--ink); }
.accent-red { --accent: var(--red); }
.accent-blue { --accent: var(--blue); }
.accent-green { --accent: var(--green); }
.accent-yellow { --accent: var(--yellow); }
.topic-card-index {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--red);
}
.topic-card-name {
  display: block;
  margin: 0.3em 0 0.5em;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.35rem;
  text-transform: uppercase;
}
.topic-card-kind {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

/* Footer. */
.colophon { margin-top: 4.5rem; }
.colophon-inner {
  max-width: var(--frame);
  margin: 0 auto;
  padding: 1.1rem var(--gutter) 2.6rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 2rem;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.09em;
}
.colophon a { text-decoration: none; }
.colophon a:hover { background: var(--ink); color: var(--paper); }

@media (max-width: 50rem) {
  .page::before { display: none; }
  .brand-tagline { display: none; }
  .masthead-inner { justify-content: flex-start; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .topic-card, .topic-card:hover { transition: none; transform: none; }
}

@media print {
  .masthead, .colophon, .dither, .page::before { display: none; }
  body { background: #fff; }
}