/* Argentum landing page.
   Dark palette by default (:root); a light variant replaces it under
   `prefers-color-scheme: light`. Every colour pair below was checked against
   WCAG contrast (>= 4.5:1 for body/link text) before being committed — see
   the deployment task's report for the computed ratios. */

:root {
  --bg: #14171c;
  --surface: #1c222b;
  --text: #e6e8eb;
  --muted: #a9b0bb;
  --link: #8ab4ff;
  --border: #323a46;
  --focus: #ffb703;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f7f7f8;
    --surface: #ffffff;
    --text: #1b1e23;
    --muted: #50565f;
    --link: #0552b5;
    --border: #d7dbe0;
    --focus: #0552b5;
  }
}

* {
  box-sizing: border-box;
}

html {
  color-scheme: dark light;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.5;
  font-size: 1rem;
}

.page {
  max-width: 42rem;
  margin: 0 auto;
  padding: 2rem 1rem 1rem;
}

h1, h2, h3 {
  line-height: 1.25;
}

h1 {
  font-size: 2rem;
  margin: 0 0 0.5rem;
}

h2 {
  font-size: 1.25rem;
  margin: 2rem 0 0.75rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.4rem;
}

h3 {
  font-size: 1.05rem;
  margin: 0 0 0.5rem;
}

.hero {
  margin-bottom: 1rem;
}

.lead {
  color: var(--muted);
  max-width: 38rem;
}

/* The one thing a visitor has to read before the feature list: there is no
   self-service sign-up here. Full --text rather than --muted, and a left rule
   in the focus colour, so it reads as a statement of fact and not as the small
   print underneath the lead. */
.notice {
  color: var(--text);
  max-width: 38rem;
  border-left: 3px solid var(--focus);
  padding-left: 0.75rem;
}

section ul {
  margin: 0;
  padding-left: 1.25rem;
}

section li {
  margin: 0.4rem 0;
}

.cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 640px) {
  .cards {
    grid-template-columns: 1fr 1fr;
  }
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  padding: 1rem 1.25rem;
}

.card p {
  margin: 0 0 0.5rem;
}

.card p:last-child {
  margin-bottom: 0;
}

code {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 0.25rem;
  padding: 0.05rem 0.35rem;
  font-family: ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.9em;
}

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

a:hover {
  text-decoration-thickness: 2px;
}

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

footer {
  max-width: 42rem;
  margin: 2rem auto 0;
  padding: 1rem 1rem 2rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.875rem;
}

footer p {
  margin: 0.35rem 0;
}