:root {
  --bg: #f4f8fa;
  --surface: #ffffff;
  --text: #0d2433;
  --muted: #4b6475;
  --accent: #0b6e8a;
  --border: #d7e3ea;
  --banner: #b45309;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #071a26;
    --surface: #0d2738;
    --text: #e6f1f6;
    --muted: #9db6c4;
    --accent: #5fd4e8;
    --border: #1d3d50;
    --banner: #f59e0b;
  }
}
* { box-sizing: border-box; }
html { background: var(--bg); }
body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
a { color: var(--accent); }
.banner {
  background: var(--banner);
  color: #fff;
  text-align: center;
  font-size: 14px;
  padding: 4px 16px;
}
.top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 960px;
  width: 100%;
  margin: 0 auto;
  padding: 20px 16px;
}
.mark { font-weight: 700; letter-spacing: 0.02em; }
.signin {
  text-decoration: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 14px;
}
main { flex: 1; max-width: 960px; width: 100%; margin: 0 auto; padding: 0 16px; }
.hero { padding: 48px 0 32px; }
.hero h1 { font-size: clamp(36px, 7vw, 56px); line-height: 1.1; margin: 0 0 12px; }
.hero p { font-size: 20px; color: var(--muted); margin: 0; }
.products { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.product {
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  color: var(--text);
  text-decoration: none;
}
a.product:hover, a.product:focus-visible { border-color: var(--accent); }
.product h2 { font-size: 20px; margin: 0 0 8px; }
.product p { color: var(--muted); margin: 0 0 16px; flex: 1; }
.product .go { color: var(--accent); font-weight: 600; }
.product.soon .go { color: var(--muted); font-weight: 400; }
.note { color: var(--muted); margin: 32px 0; }
footer { max-width: 960px; width: 100%; margin: 0 auto; padding: 24px 16px; color: var(--muted); font-size: 14px; }