/* Async Technology website. Plain CSS, no external requests.
   Colours are the Quarter Inch Material 3 tokens (design-spec.md §4.1).
   Light/dark follows the visitor's system setting (prefers-color-scheme). */

:root {
  color-scheme: light dark;
  --bg: #FCF9F4;            /* surface */
  --text: #1C1C1A;          /* onSurface */
  --muted: #4A463F;         /* onSurfaceVariant */
  --link: #1D6B63;          /* primary */
  --primary: #1D6B63;
  --on-primary: #FFFFFF;
  --tint: #C9EDE6;          /* primaryContainer */
  --on-tint: #00201C;       /* onPrimaryContainer */
  --card: #F7F3EE;          /* surfaceContainerLow */
  --card-strong: #F1EDE7;   /* surfaceContainer */
  --line: #CBC5BA;          /* outlineVariant (decorative only) */
  --pro: #FFDBCF;           /* tertiaryContainer */
  --on-pro: #380D00;        /* onTertiaryContainer */
  --accent: #D9653B;        /* icon terracotta, decoration only, never text */
  --focus: #1D6B63;
  --radius: 12px;
  --wrap: 68rem;
  --prose: 42rem;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", "Helvetica Neue", Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #141412;
    --text: #E6E2DC;
    --muted: #CDC6BB;
    --link: #8DD5CA;
    --primary: #8DD5CA;
    --on-primary: #003731;
    --tint: #005048;
    --on-tint: #A9F1E6;
    --card: #1C1C1A;
    --card-strong: #201F1D;
    --line: #4A463F;
    --pro: #71351C;
    --on-pro: #FFDBCF;
    --focus: #8DD5CA;
  }
}

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 1.125rem;      /* 18px: landing-page.md asks for body >= 18px */
  line-height: 1.6;
  overflow-wrap: break-word;
}

img, svg { max-width: 100%; height: auto; display: block; }

a { color: var(--link); text-decoration-thickness: 1px; text-underline-offset: 0.18em; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; border-radius: 4px; }

h1, h2, h3 { line-height: 1.2; margin: 0 0 0.5em; font-weight: 650; }
h1 { font-size: clamp(2rem, 1.4rem + 3vw, 3rem); letter-spacing: -0.01em; }
h2 { font-size: clamp(1.5rem, 1.25rem + 1.2vw, 2rem); margin-top: 0; }
h3 { font-size: 1.25rem; }
p, ul, ol { margin: 0 0 1em; }
ul, ol { padding-left: 1.4em; }
li + li { margin-top: 0.35em; }
code { font-family: ui-monospace, "Cascadia Mono", Consolas, "Roboto Mono", monospace; font-size: 0.92em; overflow-wrap: anywhere; }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 16px; }
@media (min-width: 40rem) { .wrap { padding: 0 24px; } }
/* .prose narrows the reading column but keeps it on the page's left edge */
.prose > * { max-width: var(--prose); }

/* Skip link */
.skip {
  position: absolute; left: 16px; top: -100px; z-index: 10;
  background: var(--primary); color: var(--on-primary);
  padding: 12px 16px; border-radius: 8px; font-weight: 600; text-decoration: none;
}
.skip:focus { top: 12px; }

/* Header */
.site-header { border-bottom: 1px solid var(--line); }
.site-header .wrap {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between;
  gap: 4px 24px; padding-top: 12px; padding-bottom: 12px;
}
.brand {
  display: inline-flex; align-items: center; gap: 10px; min-height: 48px;
  color: var(--text); text-decoration: none; font-weight: 650; font-size: 1.125rem;
}
.brand img { width: 32px; height: 32px; }
.site-nav ul { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 0 4px; }
.site-nav li + li { margin-top: 0; }
.site-nav a {
  display: inline-flex; align-items: center; min-height: 48px; padding: 0 10px;
  color: var(--text); text-decoration: none; font-size: 1rem; border-radius: 8px;
}
.site-nav a:hover { text-decoration: underline; }
.site-nav a[aria-current="page"] { color: var(--link); font-weight: 600; text-decoration: underline; text-decoration-thickness: 2px; }
@media (max-width: 26rem) { .site-nav a:first-child { padding-left: 0; } .site-nav li:first-child a { padding-left: 0; } }

/* Sections */
main { display: block; }
.section { padding: 48px 0; }
.section + .section { border-top: 1px solid var(--line); }
@media (min-width: 48rem) { .section { padding: 72px 0; } }
.eyebrow { font-size: 0.95rem; font-weight: 600; color: var(--muted); letter-spacing: 0.02em; margin-bottom: 0.5em; }
.lede { font-size: clamp(1.2rem, 1.1rem + 0.5vw, 1.4rem); color: var(--text); max-width: 38rem; }
.muted { color: var(--muted); }
.small { font-size: 1rem; }

/* Cards */
.card {
  background: var(--card); border-radius: var(--radius); padding: 24px;
  border: 1px solid var(--line);
}
.grid { display: grid; gap: 16px; }
@media (min-width: 48rem) { .grid-3 { grid-template-columns: repeat(3, 1fr); gap: 24px; } }
@media (min-width: 48rem) { .grid-2 { grid-template-columns: repeat(2, 1fr); gap: 24px; } }

/* App card on the home page */
.app-card { display: grid; gap: 20px; align-items: start; }
@media (min-width: 40rem) { .app-card { grid-template-columns: 96px 1fr; gap: 24px; } }
.app-card h3 { font-size: 1.5rem; margin-bottom: 0.25em; }
.app-icon { width: 96px; height: 96px; border-radius: 22px; }
.status {
  display: inline-block; background: var(--tint); color: var(--on-tint);
  font-weight: 600; font-size: 1rem; padding: 6px 14px; border-radius: 999px; margin: 0 0 1em;
}

.more { margin-top: 24px; }
.visually-hidden {
  position: absolute !important; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

/* Buttons */
.button {
  display: inline-flex; align-items: center; justify-content: center; min-height: 56px;
  padding: 0 24px; border-radius: 999px; font-weight: 600; font-size: 1.125rem;
  background: var(--primary); color: var(--on-primary); text-decoration: none;
}
.button:hover { text-decoration: underline; }
.button-tonal { background: var(--tint); color: var(--on-tint); }

/* Quarter Inch hero */
.hero { display: grid; gap: 32px; align-items: center; }
@media (min-width: 48rem) { .hero { grid-template-columns: 1fr 300px; gap: 56px; } }
.hero .app-icon { margin-bottom: 20px; }
.hero h1 { max-width: 16ch; }
.cta { display: flex; flex-wrap: wrap; gap: 12px 16px; align-items: center; margin: 24px 0 8px; }

/* Screenshots */
.shot { margin: 0; }
.shot img {
  width: 100%; max-width: 300px; margin: 0 auto; border-radius: 16px;
  border: 1px solid var(--line); background: var(--card);
}
.hero .shot img { max-width: 300px; }
.shots { display: grid; gap: 24px; grid-template-columns: 1fr; justify-items: center; margin-top: 40px; }
@media (min-width: 36rem) { .shots { grid-template-columns: repeat(2, minmax(0, 300px)); justify-content: center; } }

/* Feature lists */
.feature-list { padding-left: 1.2em; }
.feature-list li::marker { color: var(--primary); }
.pro-label {
  display: inline-block; background: var(--pro); color: var(--on-pro);
  font-size: 0.875rem; font-weight: 650; padding: 2px 8px; border-radius: 6px; vertical-align: 0.15em;
}
.note { background: var(--card-strong); border-radius: var(--radius); padding: 16px 20px; }

/* FAQ */
.faq h3 { margin-top: 1.6em; }
.faq h3:first-of-type { margin-top: 0; }

/* Policy / long text */
.doc h1 { font-size: clamp(1.75rem, 1.4rem + 2vw, 2.5rem); }
.doc h2 { font-size: 1.5rem; margin-top: 1.8em; scroll-margin-top: 16px; }
.doc h3 { font-size: 1.2rem; margin-top: 1.4em; }
.doc .meta { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 20px; margin-bottom: 1.25em; }
.doc .meta code { overflow-wrap: normal; }
.doc .meta p { margin: 0; }
.toc { font-size: 1rem; }
.toc ol { margin-bottom: 0; }
.back { font-size: 1rem; margin-bottom: 24px; }

/* Contact */
.contact-email { font-size: clamp(1.25rem, 1.1rem + 1vw, 1.6rem); font-weight: 600; overflow-wrap: anywhere; }

/* Footer */
.site-footer { border-top: 1px solid var(--line); padding: 32px 0 40px; font-size: 1rem; color: var(--muted); }
.site-footer p { margin: 0 0 0.5em; }
.site-footer a { color: var(--link); }
.footer-links { display: flex; flex-wrap: wrap; gap: 4px 20px; list-style: none; padding: 0; margin: 0 0 0.75em; }
.footer-links li + li { margin-top: 0; }
.footer-links a { display: inline-flex; align-items: center; min-height: 48px; }

@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }
@media print {
  .site-header nav, .skip, .site-footer .footer-links { display: none; }
  body { font-size: 11pt; }
  a { color: inherit; }
}