:root {
  --bg: #ffffff;
  --fg: #16181d;
  --muted: #5b6270;
  --line: #e3e6ec;
  --accent: #0a55d6;
  --soft: #f5f7fa;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115;
    --fg: #e8eaef;
    --muted: #9aa2b1;
    --line: #262a33;
    --accent: #6ea8ff;
    --soft: #171a21;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans",
               "Noto Sans JP", "Yu Gothic", sans-serif;
  line-height: 1.9;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

.wrap {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px 96px;
}

header.site {
  border-bottom: 1px solid var(--line);
  margin-bottom: 40px;
}

header.site .wrap {
  padding-top: 20px;
  padding-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 16px;
}

header.site a.brand {
  font-weight: 700;
  font-size: 17px;
  color: var(--fg);
  text-decoration: none;
  letter-spacing: .02em;
}

header.site nav {
  margin-left: auto;
  display: flex;
  gap: 18px;
  font-size: 14px;
}

header.site nav a { color: var(--muted); text-decoration: none; }
header.site nav a:hover { color: var(--accent); }

h1 {
  font-size: 28px;
  line-height: 1.5;
  margin: 8px 0 4px;
  letter-spacing: .01em;
}

h2 {
  font-size: 19px;
  margin: 44px 0 12px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  letter-spacing: .01em;
}

h3 { font-size: 16px; margin: 28px 0 6px; }

p { margin: 12px 0; }

ul, ol { padding-left: 1.4em; margin: 12px 0; }
li { margin: 6px 0; }

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

.lead {
  color: var(--muted);
  font-size: 15px;
  margin-bottom: 8px;
}

.updated {
  color: var(--muted);
  font-size: 13px;
  margin-top: 0;
}

.note {
  background: var(--soft);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 16px 20px;
  margin: 24px 0;
  font-size: 15px;
}

.note strong { display: block; margin-bottom: 4px; }

.hero {
  padding: 24px 0 8px;
}

.hero h1 { font-size: 32px; }

.cards {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  margin: 28px 0;
}

.card {
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 18px 20px;
  text-decoration: none;
  color: var(--fg);
  display: block;
  background: var(--bg);
}

.card:hover { border-color: var(--accent); }
.card b { display: block; font-size: 16px; margin-bottom: 4px; }
.card span { color: var(--muted); font-size: 14px; line-height: 1.7; }

footer.site {
  border-top: 1px solid var(--line);
  margin-top: 64px;
  padding: 28px 0;
  color: var(--muted);
  font-size: 13px;
}

footer.site .wrap { padding-bottom: 0; }

dl.faq dt { font-weight: 700; margin-top: 26px; }
dl.faq dd { margin: 6px 0 0; }

table.info {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 15px;
}

table.info th, table.info td {
  border-bottom: 1px solid var(--line);
  padding: 12px 4px;
  text-align: left;
  vertical-align: top;
}

table.info th {
  width: 34%;
  color: var(--muted);
  font-weight: 500;
}