/*
 * The landing page (the promotion plan's step 9, GitHub issue #96): a
 * plain page, light and dark, with the system's own fonts, so that
 * nothing is fetched from other sites. The colour tokens are holoml's
 * site's (its site/style.css), so the two sites read as one family;
 * every pair meets WCAG 2.2 AA (4.5:1 for text, 3:1 for the focus ring
 * and borders that matter), and site/site.test.ts checks them.
 */
:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --surface: #f4f6f9;
  --fg: #1b1e24;
  --muted: #4d5566;
  --link: #0a58a8;
  --visited: #6a3d9a;
  --border: #8a93a3;
  --rule: #d9dee6;
  --focus: #0a58a8;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111418;
    --surface: #1b2028;
    --fg: #e7e9ee;
    --muted: #aab2c0;
    --link: #8ec3ff;
    --visited: #c9a6f5;
    --border: #6b7486;
    --rule: #2c323d;
    --focus: #8ec3ff;
  }
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 1.0625rem/1.6 system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

a {
  color: var(--link);
  text-underline-offset: 0.15em;
}

a:visited {
  color: var(--visited);
}

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
  border-radius: 2px;
}

.skip {
  position: absolute;
  left: 1rem;
  top: -4rem;
  padding: 0.5rem 1rem;
  background: var(--bg);
  color: var(--link);
  border: 2px solid var(--focus);
  z-index: 10;
}

.skip:focus {
  top: 0.5rem;
}

/* The top: the logo, the name, one paragraph, and the buttons. */
.top {
  background: var(--surface);
  border-bottom: 1px solid var(--rule);
}

/* The header's two parts share one row where the window is wide enough. */
.top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem 2rem;
  max-width: 64rem;
  margin: 0 auto;
  padding: 2rem 1rem;
}

.top > div {
  flex: 1 1 24rem;
}

.logo {
  width: 11rem;
  height: 11rem;
  flex: 0 0 auto;
}

h1 {
  margin: 0 0 0.5rem;
  font-size: 2.2rem;
  line-height: 1.15;
}

.lead {
  margin: 0;
  font-size: 1.15rem;
  max-width: 44rem;
}

.buttons {
  margin: 1.25rem 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.button {
  display: inline-block;
  padding: 0.55rem 1rem;
  border: 2px solid var(--link);
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
}

.button:visited {
  color: var(--link);
}

.button:first-child {
  background: var(--link);
  color: var(--bg);
}

main {
  max-width: 64rem;
  margin: 0 auto;
  padding: 1rem 1rem 3rem;
}

section {
  margin: 2.5rem 0;
}

h2 {
  font-size: 1.6rem;
  line-height: 1.25;
  margin: 0 0 0.75rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--rule);
}

p {
  margin: 0 0 1rem;
  max-width: 50rem;
}

.note {
  color: var(--muted);
  font-size: 0.95rem;
}

/* The four pictures, two by two; one column on a narrow screen. */
.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.25rem 1.5rem;
  margin: 0 0 1rem;
}

@media (max-width: 44rem) {
  .grid {
    grid-template-columns: minmax(0, 1fr);
  }
}

figure {
  margin: 0;
}

figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--rule);
  border-radius: 6px;
  background: var(--surface);
}

figcaption {
  margin-top: 0.5rem;
  color: var(--muted);
  font-size: 0.95rem;
}

.concept {
  max-width: 24rem;
  margin: 0 0 1rem;
}

.motion {
  max-width: 45rem;
  margin: 0 0 1rem;
}

ul {
  padding-left: 1.25rem;
}

li {
  margin: 0 0 0.5rem;
}

.examples .site {
  white-space: nowrap;
}

.downloads {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  list-style: none;
  padding: 0;
  margin: 0 0 1.25rem;
}

.downloads a {
  display: inline-block;
  padding: 0.5rem 0.9rem;
  border: 2px solid var(--border);
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
}

pre {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 0.75rem 1rem;
  overflow-x: auto;
  margin: 0 0 1rem;
}

code {
  font-family: ui-monospace, 'Cascadia Mono', Consolas, 'SF Mono', Menlo, monospace;
  font-size: 0.95em;
}

p code {
  background: var(--surface);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}

.documents {
  color: var(--muted);
}