/* One page, no build step, no JavaScript. Colours are tokens so the dark and
   light variants are the same stylesheet read twice rather than two stylesheets. */
:root {
  --bg: #0b0d10;
  --panel: #12161b;
  --line: #222a33;
  --text: #e8edf2;
  --muted: #9aa7b4;
  --accent: #7aa2f7;
  --accent-ink: #0b0d10;
  --code-bg: #0e1319;
  --measure: 66ch;
  --gap: clamp(2.5rem, 6vw, 5rem);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme='dark']) {
    --bg: #ffffff;
    --panel: #f6f8fa;
    --line: #dfe4ea;
    --text: #12161b;
    --muted: #5a6672;
    --accent: #2c5bd6;
    --accent-ink: #ffffff;
    --code-bg: #f2f5f8;
  }
}

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

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 400 clamp(1rem, 0.96rem + 0.2vw, 1.0625rem) / 1.65
    ui-sans-serif, system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.skip {
  position: absolute;
  left: -9999px;
}
.skip:focus {
  left: 1rem;
  top: 1rem;
  z-index: 10;
  padding: 0.6rem 1rem;
  background: var(--accent);
  color: var(--accent-ink);
  border-radius: 6px;
}

a {
  color: var(--accent);
  text-underline-offset: 0.2em;
}
a:hover {
  text-decoration-thickness: 2px;
}

/* ---- chrome ---- */

.bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
  align-items: center;
  justify-content: space-between;
  max-width: 72rem;
  margin: 0 auto;
  padding: 1.25rem 1rem;
  border-bottom: 1px solid var(--line);
}

.wordmark {
  font-weight: 650;
  letter-spacing: -0.015em;
  font-size: 1.0625rem;
}

.bar nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  font-size: 0.9375rem;
}
.bar nav a {
  color: var(--muted);
  text-decoration: none;
}
.bar nav a:hover {
  color: var(--text);
}

main {
  max-width: 72rem;
  margin: 0 auto;
  padding: 0 1rem;
}

section {
  padding: var(--gap) 0;
  border-bottom: 1px solid var(--line);
}
section:last-of-type {
  border-bottom: 0;
}

/* ---- hero ---- */

.hero {
  padding-top: clamp(3rem, 9vw, 6.5rem);
}

h1 {
  margin: 0 0 1.25rem;
  max-width: 18ch;
  /* The lower bound has to fit the longest word at the narrowest phone, or one
     line overflows and takes the whole document's width with it. */
  font-size: clamp(1.9rem, 1.05rem + 3.7vw, 4rem);
  line-height: 1.06;
  letter-spacing: -0.03em;
  font-weight: 640;
  overflow-wrap: break-word;
  text-wrap: balance;
}

.lede {
  max-width: var(--measure);
  margin: 0 0 2rem;
  font-size: clamp(1.0625rem, 1rem + 0.4vw, 1.25rem);
  color: var(--muted);
}

.status {
  margin: 1.75rem 0 0;
  font-size: 0.875rem;
  color: var(--muted);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 0;
}

.button {
  display: inline-block;
  padding: 0.7rem 1.15rem;
  border: 1px solid transparent;
  border-radius: 8px;
  background: var(--accent);
  color: var(--accent-ink);
  font-weight: 550;
  font-size: 0.9375rem;
  text-decoration: none;
}
.button:hover {
  filter: brightness(1.08);
}
.button.ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--line);
}
.button.ghost:hover {
  border-color: var(--muted);
  filter: none;
}

/* ---- text ---- */

h2 {
  margin: 0 0 1.25rem;
  overflow-wrap: break-word;
  font-size: clamp(1.5rem, 1.2rem + 1.1vw, 2rem);
  letter-spacing: -0.02em;
  line-height: 1.2;
  font-weight: 620;
}

h3 {
  margin: 0 0 0.6rem;
  font-size: 1.0625rem;
  letter-spacing: -0.01em;
  font-weight: 600;
}

p {
  max-width: var(--measure);
}

section > p {
  color: var(--muted);
}

abbr {
  text-decoration: underline dotted;
  cursor: help;
}

/* ---- the four cards ---- */

/* Two by two rather than auto-fit: four cards in a three-column track leave one
   alone on a second row, which reads as a mistake rather than as a fourth point. */
.grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
}

@media (min-width: 46rem) {
  .grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.grid article {
  padding: 1.4rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
}

.grid p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9375rem;
}

/* ---- code ---- */

pre {
  max-width: var(--measure);
  margin: 1.25rem 0;
  padding: 1.1rem 1.25rem;
  overflow-x: auto;
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: 10px;
}

code {
  font-family: ui-monospace, SFMono-Regular, 'SF Mono', Menlo, Consolas, monospace;
  font-size: 0.875rem;
}

pre code {
  color: var(--text);
  line-height: 1.7;
}

p code {
  padding: 0.1em 0.35em;
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: 5px;
}

/* An aside under a block of commands: the reason one of them is there, for a
   reader who would otherwise wonder why three volumes are made by hand. */
.note {
  max-width: var(--measure);
  color: var(--muted);
  font-size: 0.9375rem;
}

/* ---- footer ---- */

footer {
  max-width: 72rem;
  margin: 0 auto;
  padding: 2.5rem 1rem 4rem;
  border-top: 1px solid var(--line);
}

footer p {
  margin: 0;
  color: var(--muted);
  font-size: 0.875rem;
}