/* Checkmate marketing + legal site.
   One stylesheet, no framework, no external requests — the CSP on this host
   blocks third-party assets and the whole site is four static pages. */

:root {
  color-scheme: light dark;

  --bg: #f6f4f1;
  --surface: #ffffff;
  --surface-alt: #edeae5;
  --border: #dcd7cf;
  --text: #1d1b18;
  --muted: #6b655c;
  --accent: #2f6f4e;
  --accent-text: #ffffff;
  --board-light: #efd9b4;
  --board-dark: #b58863;
  --radius: 12px;
  --max: 720px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15161a;
    --surface: #1e2026;
    --surface-alt: #262931;
    --border: #343842;
    --text: #f1efea;
    --muted: #9a9da6;
    --accent: #5fbf8c;
    --accent-text: #0e1512;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 20px; }

header.site {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}
header.site .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-top: 14px;
  padding-bottom: 14px;
}
.brand { display: flex; align-items: center; gap: 9px; font-weight: 800; font-size: 17px; text-decoration: none; color: var(--text); }
.brand .glyphs { font-size: 21px; letter-spacing: -2px; }
nav a { color: var(--muted); text-decoration: none; margin-left: 18px; font-size: 14px; font-weight: 600; }
nav a:hover, nav a:focus { color: var(--accent); }

.hero { text-align: center; padding: 64px 0 40px; }
.hero h1 { font-size: clamp(32px, 7vw, 48px); line-height: 1.1; margin: 0 0 14px; letter-spacing: -1px; }
.hero p.lead { font-size: 18px; color: var(--muted); margin: 0 auto 28px; max-width: 30em; }

/* A real 8x8 grid rather than a screenshot, so the page stays tiny and sharp. */
.board {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  width: min(320px, 80vw);
  margin: 0 auto 36px;
  border: 3px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 12px 34px rgba(0, 0, 0, 0.16);
}
.board div {
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  font-size: clamp(16px, 5.4vw, 30px);
  line-height: 1;
}
.board .l { background: var(--board-light); }
.board .d { background: var(--board-dark); }
.board .w { color: #fff; text-shadow: 0 0 2px #2a2724, 0 1px 1px rgba(0,0,0,.45); }
.board .b { color: #1c1b19; text-shadow: 0 0 2px rgba(255,255,255,.5); }

.cta { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.button {
  display: inline-block;
  padding: 13px 24px;
  border-radius: var(--radius);
  background: var(--accent);
  color: var(--accent-text);
  text-decoration: none;
  font-weight: 700;
  border: 1px solid var(--accent);
}
.button.secondary { background: var(--surface); color: var(--text); border-color: var(--border); }
.button:hover { opacity: 0.9; }

.features { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); padding: 20px 0 56px; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; }
.card h3 { margin: 0 0 6px; font-size: 16px; }
.card p { margin: 0; color: var(--muted); font-size: 14px; }

main.doc { padding: 40px 0 64px; }
main.doc h1 { font-size: 30px; margin: 0 0 6px; letter-spacing: -0.5px; }
main.doc .updated { color: var(--muted); font-size: 14px; margin: 0 0 32px; }
main.doc h2 { font-size: 19px; margin: 34px 0 10px; }
main.doc h3 { font-size: 16px; margin: 22px 0 6px; }
main.doc p, main.doc li { color: var(--text); }
main.doc ul { padding-left: 22px; }
main.doc li { margin-bottom: 7px; }
main.doc a { color: var(--accent); }

.callout {
  background: var(--surface-alt);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 15px 18px;
  margin: 22px 0;
}
.callout p { margin: 0; }

table.data { width: 100%; border-collapse: collapse; margin: 18px 0; font-size: 14px; }
table.data th, table.data td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--border); vertical-align: top; }
table.data th { color: var(--muted); font-weight: 700; }
.scroll-x { overflow-x: auto; }

footer.site { border-top: 1px solid var(--border); padding: 26px 0 40px; color: var(--muted); font-size: 14px; }
footer.site .wrap { display: flex; justify-content: space-between; gap: 14px; flex-wrap: wrap; }
footer.site a { color: var(--muted); text-decoration: none; margin-right: 16px; }
footer.site a:hover { color: var(--accent); }

@media (max-width: 520px) {
  header.site .wrap { flex-direction: column; align-items: flex-start; gap: 8px; }
  nav a { margin: 0 16px 0 0; }
}