/* 共通スタイル(外部フォント・CDN不使用) */
:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --surface: #f5f6f8;
  --text: #1b1f24;
  --muted: #4a5360;
  --border: #c9ced6;
  --accent: #0b5cad;
  --accent-text: #ffffff;
  --link: #0a55a0;
  --notice-bg: #fff6dc;
  --notice-border: #c99400;
  --error: #b00020;
  --ok-bg: #e8f3ea;
  --focus: #e07000;
  --maxw: 46rem;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14171b;
    --surface: #1f242a;
    --text: #e8eaed;
    --muted: #b4bcc6;
    --border: #46505c;
    --accent: #6fb1f5;
    --accent-text: #0b1520;
    --link: #8cc4ff;
    --notice-bg: #2e2810;
    --notice-border: #c9a43a;
    --error: #ff8a80;
    --ok-bg: #1c2e21;
    --focus: #ffb347;
  }
}

* { 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", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic UI", Meiryo, sans-serif;
  font-size: 1rem;
  line-height: 1.75;
}
a { color: var(--link); text-underline-offset: 0.15em; overflow-wrap: anywhere; }
main, li, dd, td { overflow-wrap: anywhere; }
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, summary:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}
.skip-link { position: absolute; left: -9999px; top: 0; }
.skip-link:focus { left: 1rem; top: 0.5rem; background: var(--bg); padding: 0.5rem; z-index: 10; }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 1rem; }

.site-header { border-bottom: 1px solid var(--border); background: var(--surface); }
.site-header .container { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 0.5rem 1rem; padding-top: 0.75rem; padding-bottom: 0.75rem; }
.site-name { font-weight: 700; font-size: 1.1rem; color: var(--text); text-decoration: none; }
.site-nav ul { list-style: none; display: flex; flex-wrap: wrap; gap: 0.25rem 1rem; margin: 0; padding: 0; }

main { padding: 1.5rem 0 2rem; }
h1 { font-size: 1.5rem; line-height: 1.4; margin: 0.5rem 0 1rem; }
h2 { font-size: 1.25rem; line-height: 1.4; margin: 2rem 0 0.75rem; padding-bottom: 0.25rem; border-bottom: 1px solid var(--border); }
h3 { font-size: 1.05rem; margin: 1.5rem 0 0.5rem; }
p, ul, ol { margin: 0 0 1rem; }
.lead { color: var(--muted); }
.meta { color: var(--muted); font-size: 0.9rem; }

.notice { background: var(--notice-bg); border-left: 4px solid var(--notice-border); padding: 0.75rem 1rem; margin: 1rem 0; border-radius: 4px; }
.notice ul { margin-bottom: 0; padding-left: 1.25rem; }
.card-list { list-style: none; padding: 0; display: grid; gap: 1rem; }
.card { border: 1px solid var(--border); border-radius: 8px; padding: 1rem; background: var(--surface); }
.card h3 { margin-top: 0; }

/* フォーム */
fieldset { min-width: 0; border: 1px solid var(--border); border-radius: 8px; padding: 1rem; margin: 0 0 1.25rem; }
legend { font-weight: 700; padding: 0 0.25rem; }
.field { margin-bottom: 1rem; }
.field label { display: block; font-weight: 600; margin-bottom: 0.25rem; }
.hint { display: block; color: var(--muted); font-size: 0.875rem; }
input[type="text"], input[type="number"], select {
  font: inherit; color: var(--text); background: var(--bg);
  border: 1px solid var(--border); border-radius: 6px; padding: 0.5rem 0.6rem; width: 100%; max-width: 20rem; min-height: 2.75rem;
}
input[inputmode="numeric"] { text-align: right; }
input[aria-invalid="true"] { border-color: var(--error); border-width: 2px; }
.error-text { color: var(--error); font-size: 0.9rem; }
.checkbox { display: flex; gap: 0.5rem; align-items: flex-start; }
.checkbox input { width: 1.25rem; height: 1.25rem; margin-top: 0.3rem; }
button, .button {
  font: inherit; display: inline-block; cursor: pointer; text-decoration: none;
  border-radius: 6px; padding: 0.55rem 1.1rem; min-height: 2.75rem;
  border: 1px solid var(--accent); background: var(--accent); color: var(--accent-text);
}
button.secondary, .button.secondary { background: transparent; color: var(--link); border-color: var(--border); }
.actions { display: flex; flex-wrap: wrap; gap: 0.75rem; margin: 1rem 0; }

/* 表 */
.table-wrap { overflow-x: auto; margin: 0 0 1rem; }
table { border-collapse: collapse; width: 100%; font-size: 0.95rem; }
th, td { border: 1px solid var(--border); padding: 0.45rem 0.6rem; text-align: left; vertical-align: top; }
th { background: var(--surface); }
td.num, th.num { text-align: right; white-space: nowrap; font-variant-numeric: tabular-nums; }
caption { text-align: left; font-weight: 600; padding-bottom: 0.25rem; }

.visually-hidden-label { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.rows-table input, .rows-table select { max-width: none; min-width: 6.5rem; }

.result { border: 2px solid var(--accent); border-radius: 8px; padding: 1rem; margin: 1rem 0; background: var(--surface); }
.result:empty { display: none; }
.result .big { font-size: 1.4rem; font-weight: 700; }

/* 将来、広告枠を置く場合は操作部・結果表示から離した位置(.reserve-gap の後)に限る */
.reserve-gap { margin-top: 3rem; }

details { border: 1px solid var(--border); border-radius: 6px; padding: 0.5rem 0.75rem; margin: 0 0 1rem; }
summary { cursor: pointer; font-weight: 600; }

.site-footer { border-top: 1px solid var(--border); background: var(--surface); padding: 1.25rem 0 2rem; font-size: 0.9rem; color: var(--muted); }
.site-footer ul { list-style: none; padding: 0; display: flex; flex-wrap: wrap; gap: 0.25rem 1.25rem; margin: 0 0 0.75rem; }

@media (max-width: 600px) {
  h1 { font-size: 1.3rem; }
  .rows-table thead { display: none; }
  .rows-table tr { display: block; border: 1px solid var(--border); border-radius: 6px; margin-bottom: 0.75rem; padding: 0.5rem; }
  .rows-table td { display: block; border: none; padding: 0.25rem 0; }
  .rows-table td::before { content: attr(data-label); display: block; font-size: 0.85rem; color: var(--muted); }
}
@media print {
  .site-nav, .actions, .skip-link { display: none; }
}