:root {
  --bg: #ffffff;
  --text: #1f2328;
  --muted: #59636e;
  --line: #d8dee4;
  --accent: #1a5fb4;
  --soft: #f6f8fa;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15181c;
    --text: #e6e8eb;
    --muted: #a0a8b1;
    --line: #343a42;
    --accent: #7fb2f0;
    --soft: #1d2126;
  }
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", Meiryo, sans-serif;
  font-size: 16px;
  line-height: 1.85;
  overflow-wrap: anywhere;
}

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

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

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

.site-header .wrap {
  display: flex;
  align-items: center;
  min-height: 60px;
}

.site-name {
  font-weight: 700;
  font-size: 18px;
  color: var(--text);
  text-decoration: none;
  letter-spacing: 0.04em;
}

main {
  padding: 40px 0 64px;
}

h1 {
  font-size: 28px;
  line-height: 1.4;
  margin: 0 0 24px;
}

h2 {
  font-size: 21px;
  line-height: 1.5;
  margin: 48px 0 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
}

h3 {
  font-size: 17px;
  margin: 28px 0 8px;
}

p, ul, ol { margin: 0 0 16px; }

ul, ol { padding-left: 1.5em; }

li { margin-bottom: 4px; }

li > ul { margin: 4px 0 0; }

.lead {
  font-size: 17px;
  color: var(--text);
}

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

.info th, .info td {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 12px 8px;
  text-align: left;
  vertical-align: top;
}

.info th {
  width: 8em;
  background: var(--soft);
  font-weight: 600;
  white-space: nowrap;
}

.note {
  background: var(--soft);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 12px 16px;
}

.date {
  margin-top: 40px;
  color: var(--muted);
  font-size: 14px;
}

.site-footer {
  border-top: 1px solid var(--line);
  background: var(--soft);
  padding: 32px 0;
  font-size: 14px;
  color: var(--muted);
}

.site-footer p { margin: 0 0 8px; }

.site-footer .footer-name {
  color: var(--text);
  font-weight: 700;
}

.footer-links {
  list-style: none;
  padding: 0;
  margin: 16px 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
}

@media (max-width: 480px) {
  h1 { font-size: 24px; }
  h2 { font-size: 19px; }
  .info th { width: 6.5em; white-space: normal; }
}