:root {
  --bg: #ffffff;
  --fg: #1f2328;
  --muted: #59636e;
  --line: #d1d9e0;
  --soft: #f6f8fa;
  --accent: #0a5cad;
  --good: #1a7f37;
  --warn: #9a6700;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117;
    --fg: #e6edf3;
    --muted: #9198a1;
    --line: #3d444d;
    --soft: #151b23;
    --accent: #4493f8;
    --good: #3fb950;
    --warn: #d29922;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: system-ui, -apple-system, "Segoe UI", "Hiragino Sans", "Noto Sans JP", Meiryo, sans-serif;
  line-height: 1.75;
}
a { color: var(--accent); }
header.site, footer.site { border-bottom: 1px solid var(--line); }
footer.site { border-top: 1px solid var(--line); border-bottom: none; margin-top: 48px; color: var(--muted); font-size: 0.9rem; }
.wrap { max-width: 760px; margin: 0 auto; padding: 16px; }
header.site a { color: var(--fg); text-decoration: none; font-weight: 700; }
h1 { font-size: 1.6rem; line-height: 1.4; margin: 24px 0 8px; }
h2 { font-size: 1.25rem; margin: 40px 0 8px; padding-bottom: 4px; border-bottom: 1px solid var(--line); }
h3 { font-size: 1.05rem; margin: 24px 0 4px; }
.lead { color: var(--muted); margin-top: 0; }
.meta { color: var(--muted); font-size: 0.85rem; }
.card { border: 1px solid var(--line); border-radius: 8px; padding: 16px; background: var(--soft); }
label { display: block; font-weight: 600; margin-top: 16px; }
.hint { display: block; color: var(--muted); font-size: 0.85rem; font-weight: 400; }
input[type="number"], select {
  width: 100%;
  font-size: 1.05rem;
  padding: 8px 10px;
  margin-top: 4px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--bg);
  color: var(--fg);
}
.row { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 8px; }
.check { font-weight: 400; display: flex; gap: 8px; align-items: center; }
table { width: 100%; border-collapse: collapse; margin-top: 8px; }
th, td { text-align: left; padding: 8px; border-bottom: 1px solid var(--line); vertical-align: top; }
td.num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
.big { font-size: 1.4rem; font-weight: 700; }
.good { color: var(--good); }
.warn { color: var(--warn); }
.formula { font-family: ui-monospace, Consolas, monospace; background: var(--soft); padding: 8px 12px; border-radius: 6px; overflow-x: auto; }
ul.tools { list-style: none; padding: 0; }
ul.tools li { border: 1px solid var(--line); border-radius: 8px; padding: 12px 16px; margin: 8px 0; }
ul.tools a { font-weight: 700; }