:root {
  --text: #1d2733;
  --muted: #5b6875;
  --accent: #2f6db5;
  --line: #e4e8ec;
  --bg: #ffffff;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

main {
  max-width: 680px;
  margin: 0 auto;
  padding: 48px 20px 32px;
}

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

.hero { text-align: center; padding: 24px 0 8px; }
.hero img { width: 160px; height: auto; }
.hero h1 { font-size: 2rem; margin: 16px 0 8px; letter-spacing: -0.01em; }
.hero p { color: var(--muted); margin: 0 auto; max-width: 520px; }

.features { list-style: none; padding: 0; margin: 40px 0; display: grid; gap: 16px; }
.features li { border: 1px solid var(--line); border-radius: 10px; padding: 16px 20px; }
.features strong { display: block; }
.features span { color: var(--muted); font-size: 0.95rem; }

.doc h1 { font-size: 1.8rem; margin: 0 0 4px; }
.doc .updated { color: var(--muted); margin: 0 0 32px; }
.doc h2 { font-size: 1.2rem; margin: 32px 0 8px; }

.back { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; color: var(--text); font-weight: 600; margin-bottom: 32px; }
.back img { width: 36px; height: auto; }

footer {
  max-width: 680px;
  margin: 0 auto;
  padding: 24px 20px 40px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.9rem;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
}
footer a { color: var(--muted); }