:root {
  --bg: #f7f7f5;
  --fg: #16161a;
  --muted: #5c5c66;
  --accent: #ff4d2e;
  --line: #e2e2dc;
  --card: #ffffff;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111114;
    --fg: #f2f2f0;
    --muted: #a0a0aa;
    --accent: #ff6a4d;
    --line: #26262c;
    --card: #18181c;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  line-height: 1.6;
}

.wrap { max-width: 760px; margin: 0 auto; padding: 0 16px; }

header { border-bottom: 1px solid var(--line); }
header .wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { font-weight: 800; font-size: 20px; letter-spacing: -0.02em; color: var(--fg); text-decoration: none; }
.logo img { display: block; height: 40px; width: auto; }
nav a { color: var(--muted); text-decoration: none; margin-left: 20px; font-size: 15px; }
nav a:hover { color: var(--fg); }

.hero { padding: 96px 0 72px; }
.hero h1 { font-size: clamp(40px, 8vw, 72px); line-height: 1.05; letter-spacing: -0.03em; margin: 0 0 20px; }
.hero h1 span { color: var(--accent); }
.hero p { font-size: 19px; color: var(--muted); max-width: 520px; margin: 0; }

section { padding: 48px 0; border-top: 1px solid var(--line); }
section h2 { font-size: 24px; margin: 0 0 16px; letter-spacing: -0.01em; }

.card { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 24px; color: var(--muted); }

a { color: var(--accent); }

.doc { padding: 56px 0; }
.doc h1 { font-size: 36px; letter-spacing: -0.02em; margin: 0 0 8px; }
.doc .date { color: var(--muted); margin: 0 0 32px; }
.doc h2 { font-size: 20px; margin: 36px 0 8px; }
.doc ul { padding-left: 20px; }

footer { border-top: 1px solid var(--line); padding: 32px 0; color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 16px; justify-content: space-between; }
footer a { color: var(--muted); }