/* 56 AI Labs website: design B "Paper" (issue #7).
   Colours come from the 56 AI Labs design system's light surfaces; the 56 mark follows the
   Mobile Native Design Guide (ai-ink disc, on-ai digits, ai-gold → ai-mint → ai-sky ring). */

:root {
  --paper: #fbf8f0;      /* surface */
  --ink: #1c1b17;        /* ink */
  --ink-soft: #55503f;   /* ink-soft: secondary text, 7.6:1 on paper */
  --accent: #854f0b;     /* guide-brown: links, 7.0:1 on paper */
  --rule: #e6dfcc;
  --tint: #f3e9c9;       /* gold-tint: footer band */
  --ai-ink: #11151a;
  --on-ai: #f4eedf;
  --ai-gold: #f5c86b;
  --ai-mint: #7dd8b5;
  --ai-sky: #8fc2f2;
  --font: -apple-system, "SF Pro Display", "SF Pro Text", system-ui, "Segoe UI", "Helvetica Neue", sans-serif;
  --max: 1280px;
  --gutter: 80px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
main { flex: 1; }

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

.container { width: min(100% - 2 * var(--gutter), var(--max)); margin: 0 auto; }

/* ---- The 56 mark ---- */
.mark {
  --size: 30px;
  width: var(--size); height: var(--size); flex-shrink: 0;
  border-radius: 50%;
  padding: max(1.5px, calc(var(--size) * 0.035));
  background: linear-gradient(135deg, var(--ai-gold), var(--ai-mint) 55%, var(--ai-sky));
  display: inline-block;
}
.mark span {
  width: 100%; height: 100%; border-radius: 50%;
  background: var(--ai-ink); color: var(--on-ai);
  display: flex; align-items: center; justify-content: center;
  font-size: calc(var(--size) * 0.4); font-weight: 600; letter-spacing: -0.03em; line-height: 1;
}

/* ---- Header ---- */
.site-header { border-bottom: 1px solid var(--rule); }
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 24px 0; }
.brand { display: flex; align-items: center; gap: 12px; color: var(--ink); }
.brand:hover { text-decoration: none; }
.brand-name { font-size: 20px; font-weight: 700; letter-spacing: -0.02em; }
.site-header nav { display: flex; gap: 28px; font-size: 16px; font-weight: 500; }
.site-header nav a { color: var(--ink-soft); }
.site-header nav a:hover { color: var(--ink); }

/* ---- Hero ---- */
.hero { border-bottom: 1px solid var(--rule); padding: 150px 0 130px; }
.hero.bare { border-bottom: 0; }
.hero h1 {
  margin: 0 0 28px;
  font-size: clamp(3rem, 7.4vw, 7rem);
  line-height: 0.98; letter-spacing: -0.045em; font-weight: 800;
  max-width: 12ch;
}
.lead { margin: 0; font-size: clamp(1.125rem, 1.7vw, 1.5rem); line-height: 1.5; color: var(--ink-soft); max-width: 34ch; }
.eyebrow { font-size: 13px; font-weight: 700; letter-spacing: 0.06em; color: var(--accent); margin-bottom: 18px; }

/* ---- Contact columns ---- */
.columns { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 48px; padding: 88px 0; }
.col { display: flex; flex-direction: column; gap: 10px; padding-top: 20px; border-top: 2px solid var(--ink); }
.label { font-size: 13px; font-weight: 700; letter-spacing: 0.06em; color: var(--ink-soft); }
.value { font-size: 22px; font-weight: 600; color: var(--ink); overflow-wrap: anywhere; }
a.value:hover { color: var(--accent); }
.note { font-size: 15px; color: var(--ink-soft); }

/* ---- Buttons (404) ---- */
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 36px; }
.button {
  display: inline-flex; align-items: center; justify-content: center;
  height: 48px; padding: 0 24px; border-radius: 999px;
  font-size: 16px; font-weight: 600; border: 1.5px solid var(--ink);
}
.button:hover { text-decoration: none; }
.button.primary { background: var(--ink); color: var(--paper); }
.button.secondary { color: var(--ink); }
.button.secondary:hover { background: var(--tint); }

/* ---- Reading pages (support, privacy, terms) ---- */
.page-head { border-bottom: 1px solid var(--rule); padding: 110px 0 70px; }
.page-head h1 { margin: 0 0 20px; font-size: clamp(2.5rem, 5.4vw, 4.5rem); line-height: 1; letter-spacing: -0.04em; font-weight: 800; }
.page-head .lead { max-width: 46ch; }
.prose { max-width: 720px; padding: 56px 0 96px; font-size: 17px; line-height: 1.7; }
.prose h2 { font-size: 24px; letter-spacing: -0.02em; line-height: 1.25; margin: 0 0 14px; }
.prose h3 { font-size: 18px; margin: 28px 0 8px; }
.prose p { margin: 0 0 14px; }
.prose ul { margin: 0 0 14px; padding-left: 22px; }
.prose li { margin: 6px 0; }
.prose a { text-decoration: underline; text-underline-offset: 3px; text-decoration-color: rgba(133, 79, 11, 0.4); }
.prose .section { padding-top: 32px; margin-top: 32px; border-top: 1px solid var(--rule); }
.prose .section:first-child { padding-top: 0; margin-top: 0; border-top: 0; }
.prose .email { font-size: 28px; font-weight: 700; letter-spacing: -0.02em; margin: 0 0 32px; }
.prose .email a { text-decoration: none; color: var(--ink); border-bottom: 2px solid var(--ink); }
.prose .email a:hover { color: var(--accent); border-color: var(--accent); }

/* ---- Footer ---- */
.site-footer { background: var(--tint); border-top: 1px solid var(--rule); }
.footer-inner { display: flex; justify-content: space-between; align-items: flex-start; gap: 24px; padding: 32px 0 40px; font-size: 14px; line-height: 1.7; color: var(--ink-soft); }
.footer-inner p { margin: 0; }
.footer-links { display: flex; gap: 20px; white-space: nowrap; }
.footer-links a { color: var(--ink); }

@media (max-width: 720px) {
  :root { --gutter: 20px; }
  .brand-name { font-size: 18px; }
  .site-header nav { gap: 20px; font-size: 15px; }
  .hero { padding: 56px 0; }
  .columns { grid-template-columns: 1fr; gap: 28px; padding: 48px 0; }
  .value { font-size: 20px; }
  .page-head { padding: 56px 0 40px; }
  .prose { padding: 40px 0 64px; }
  .prose .email { font-size: 22px; }
  .footer-inner { flex-direction: column; gap: 20px; }
  .footer-links { flex-wrap: wrap; }
}

.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }