:root {
  --bg: #f7f7f4;
  --surface: #ffffff;
  --text: #1f2328;
  --muted: #5d636b;
  --border: #dedcd5;
  --accent: #0b6e4f;
  --accent-weak: #e3f1eb;
  --warn: #9a3412;
  --radius: 10px;
  --maxw: 760px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15171a;
    --surface: #1d2024;
    --text: #e8e6e1;
    --muted: #a3a8ae;
    --border: #33373d;
    --accent: #5cc8a0;
    --accent-weak: #1d332b;
    --warn: #fdba74;
    color-scheme: dark;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Hiragino Sans", "Noto Sans JP", "Yu Gothic UI", Meiryo, sans-serif;
  line-height: 1.8;
  font-size: 16px;
}
a { color: var(--accent); }
img { max-width: 100%; height: auto; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 16px; }
main .wrap > *, article > * { min-width: 0; max-width: 100%; }
.lead, .article-body, .result-item dd { overflow-wrap: anywhere; }

.site-header { background: var(--surface); border-bottom: 1px solid var(--border); }
.site-header .wrap { display: flex; flex-wrap: wrap; align-items: center; gap: 4px 16px; padding-top: 10px; padding-bottom: 10px; }
.site-name { font-weight: 700; font-size: 1.1rem; color: var(--text); text-decoration: none; }
.site-nav { display: flex; flex-wrap: wrap; gap: 4px 12px; font-size: 0.9rem; }
.site-nav a { color: var(--muted); text-decoration: none; }
.site-nav a:hover { color: var(--accent); }
.lang-switch { margin-left: auto; font-size: 0.85rem; color: var(--muted); text-decoration: none; border: 1px solid var(--border); border-radius: 999px; padding: 2px 10px; white-space: nowrap; }
.lang-switch:hover { color: var(--accent); border-color: var(--accent); }

main { padding: 20px 0 48px; }
h1 { font-size: 1.6rem; line-height: 1.4; margin: 0.4em 0; }
h2 { font-size: 1.3rem; line-height: 1.45; margin: 2em 0 0.6em; padding-bottom: 0.25em; border-bottom: 2px solid var(--accent-weak); }
h3 { font-size: 1.1rem; margin: 1.5em 0 0.4em; }
.lead { color: var(--muted); margin: 0 0 0.5em; }
.page-meta { color: var(--muted); font-size: 0.85rem; margin: 0; }

.breadcrumb { font-size: 0.85rem; color: var(--muted); }
.breadcrumb ol { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 4px; }
.breadcrumb li + li::before { content: "›"; margin-right: 4px; }
.breadcrumb a { color: var(--muted); }

.pr-notice { display: inline-block; font-size: 0.8rem; color: var(--muted); border: 1px solid var(--border); border-radius: 4px; padding: 0 8px; margin: 8px 0; }

.calc { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; margin: 20px 0; }
.calc form { display: grid; gap: 12px; }
.field label { display: block; font-weight: 600; font-size: 0.95rem; margin-bottom: 2px; }
.field .control { display: flex; align-items: center; gap: 8px; }
.field input, .field select {
  width: 100%; max-width: 320px; font: inherit; color: var(--text); background: var(--bg);
  border: 1px solid var(--border); border-radius: 6px; padding: 8px 10px; min-height: 44px;
}
.field select { max-width: 100%; }
.field input:focus, .field select:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
.field .unit { color: var(--muted); white-space: nowrap; }
.field .help { font-size: 0.8rem; color: var(--muted); margin: 2px 0 0; }
.calc-results { margin-top: 16px; border-top: 1px dashed var(--border); padding-top: 12px; }
.result-list { margin: 0; display: grid; gap: 6px; }
.result-item { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 4px 16px; padding: 6px 0; border-bottom: 1px solid var(--border); }
.result-item dt { color: var(--muted); }
.result-item dd { margin: 0; font-weight: 600; font-variant-numeric: tabular-nums; }
.result-item.is-primary { background: var(--accent-weak); border-radius: 6px; padding: 10px 12px; border-bottom: none; }
.result-item.is-primary dt { color: var(--text); font-weight: 600; }
.result-item.is-primary dd { font-size: 1.35rem; color: var(--accent); }
.calc-error { color: var(--warn); font-weight: 600; margin: 0; }
.result-notes { color: var(--muted); font-size: 0.85rem; padding-left: 1.2em; margin: 12px 0 0; }
.result-table { margin-top: 12px; }
.result-table summary { cursor: pointer; font-weight: 600; color: var(--accent); }
.table-caption { font-weight: 600; margin: 0 0 4px; }
.table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }
table { border-collapse: collapse; width: 100%; font-size: 0.9rem; font-variant-numeric: tabular-nums; }
th, td { border: 1px solid var(--border); padding: 6px 8px; text-align: right; white-space: nowrap; }
th { background: var(--accent-weak); text-align: center; }
td:first-child { text-align: center; }
.article-body th, .article-body td { white-space: normal; min-width: 4.5em; }
.article-body td:first-child { text-align: left; }
.calc-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.btn { font: inherit; font-size: 0.9rem; border: 1px solid var(--border); background: var(--bg); color: var(--text); border-radius: 6px; padding: 6px 12px; cursor: pointer; text-decoration: none; min-height: 40px; display: inline-flex; align-items: center; }
.btn:hover { border-color: var(--accent); }

.formula { background: var(--surface); border-left: 4px solid var(--accent); padding: 8px 12px; overflow-x: auto; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 0.9rem; }
.note { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 10px 14px; font-size: 0.92rem; }
.faq dt { font-weight: 700; margin-top: 1em; }
.faq dt::before { content: "Q. "; color: var(--accent); }
.faq dd { margin: 0.2em 0 0; }
.faq dd::before { content: "A. "; font-weight: 700; color: var(--muted); }

.offer { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 16px; margin: 24px 0; }
.offer h2 { margin-top: 0; border: none; font-size: 1.1rem; }
.sources { font-size: 0.88rem; color: var(--muted); }
.sources ul { padding-left: 1.2em; }

.card-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); }
.card-list a { display: block; height: 100%; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 12px 14px; text-decoration: none; color: var(--text); }
.card-list a:hover { border-color: var(--accent); }
.card-title { display: block; font-weight: 700; color: var(--accent); }
.card-desc { display: block; font-size: 0.85rem; color: var(--muted); line-height: 1.6; margin-top: 4px; }
.search-box { width: 100%; font: inherit; padding: 10px 12px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); color: var(--text); min-height: 44px; }

.site-footer { border-top: 1px solid var(--border); background: var(--surface); font-size: 0.85rem; color: var(--muted); padding: 20px 0 32px; }
.site-footer nav { display: flex; flex-wrap: wrap; gap: 4px 16px; margin-bottom: 8px; }
.site-footer a { color: var(--muted); }
[hidden] { display: none !important; }