:root {
  --bg: #f7f8fa;
  --card: #ffffff;
  --text: #1c1e21;
  --muted: #5c6470;
  --border: #e3e6ea;
  --accent: #2f6bff;
  --accent-weak: #eaf0ff;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161a;
    --card: #1e2126;
    --text: #eceef1;
    --muted: #9aa2ad;
    --border: #2c3037;
    --accent: #6c9bff;
    --accent-weak: #23293a;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.8;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 20px;
}

header.site {
  border-bottom: 1px solid var(--border);
  background: var(--card);
}

header.site .wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 16px;
  padding-bottom: 16px;
}

header.site img {
  width: 40px;
  height: 40px;
  border-radius: 10px;
}

header.site .brand {
  font-weight: 700;
  font-size: 18px;
  text-decoration: none;
  color: var(--text);
}

nav.site {
  margin-left: auto;
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

nav.site a {
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
}

nav.site a:hover { color: var(--accent); }

main { padding: 40px 0 56px; }

.hero {
  text-align: center;
  padding: 24px 0 8px;
}

.hero img {
  width: 88px;
  height: 88px;
  border-radius: 20px;
  box-shadow: 0 6px 20px rgba(0,0,0,0.12);
}

h1 {
  font-size: 28px;
  line-height: 1.4;
  margin: 20px 0 8px;
}

.lead {
  color: var(--muted);
  font-size: 16px;
  margin: 0 auto 8px;
}

.badge {
  display: inline-block;
  background: var(--accent-weak);
  color: var(--accent);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 600;
  margin-top: 12px;
}

.cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin: 32px 0;
}

@media (max-width: 560px) {
  .cards { grid-template-columns: 1fr; }
}

.card {
  display: block;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 20px;
  text-decoration: none;
  color: var(--text);
  transition: border-color .15s, transform .15s;
}

.card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.card h3 {
  margin: 0 0 6px;
  font-size: 17px;
}

.card p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.features {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 8px 24px;
  margin: 24px 0;
}

.features ul { padding-left: 20px; }
.features li { margin: 6px 0; }

article {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 8px 28px 28px;
}

article h2 {
  font-size: 20px;
  margin-top: 32px;
  padding-top: 4px;
  border-top: 1px solid var(--border);
}

article h2:first-of-type { border-top: none; }

article h3 {
  font-size: 16px;
  margin-top: 24px;
}

article ul, article ol { padding-left: 22px; }
article li { margin: 4px 0; }

.meta {
  color: var(--muted);
  font-size: 14px;
}

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

.page-title {
  font-size: 24px;
  margin: 8px 0 24px;
}

footer.site {
  border-top: 1px solid var(--border);
  background: var(--card);
  color: var(--muted);
  font-size: 13px;
  text-align: center;
  padding: 24px 0;
}

footer.site a { color: var(--muted); }