:root {
  --bg: #f7faf8;
  --surface: #ffffff;
  --border: #dde6e0;
  --text: #16201b;
  --muted: #5b6a61;
  --accent: #1f9d6c;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0f0d;
    --surface: #141a17;
    --border: #24302a;
    --text: #eef3ef;
    --muted: #98a69d;
    --accent: #34d399;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.6 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, sans-serif;
  -webkit-text-size-adjust: 100%;
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 32px 20px 64px;
}

header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 32px;
}

header img { width: 44px; height: 44px; }

header a {
  color: var(--text);
  font-weight: 700;
  font-size: 22px;
  text-decoration: none;
}

nav {
  margin-left: auto;
  display: flex;
  gap: 16px;
  font-size: 15px;
}

nav a { color: var(--muted); font-weight: 500; font-size: 15px; }

h1 { font-size: 34px; line-height: 1.2; margin: 0 0 8px; }
h2 { font-size: 21px; margin: 40px 0 8px; }
h3 { font-size: 17px; margin: 24px 0 4px; }

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

.updated { color: var(--muted); margin: 0 0 24px; }

.summary {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 4px 20px;
  margin: 24px 0;
}

ul { padding-left: 22px; }
li { margin: 6px 0; }

footer {
  margin-top: 56px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 480px) {
  h1 { font-size: 28px; }
  nav { gap: 12px; }
}