/* 説明ページ（使い方・よくある質問・計算方法）の共通スタイル */
:root {
  --bg: #ffffff;
  --panel: #f7f7f8;
  --text: #1f2328;
  --muted: #656d76;
  --border: #d8dee4;
  --accent: #0969da;
  --station: #1a7f37;
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  font-family: system-ui, -apple-system, "Hiragino Sans", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.8;
  font-size: 16px;
}
a { color: var(--accent); }

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--panel);
  position: sticky;
  top: 0;
  z-index: 10;
}
.site-header .inner {
  max-width: 760px;
  margin: 0 auto;
  padding: 10px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}
.site-header .brand { display: flex; align-items: center; gap: 8px; font-weight: bold; color: var(--text); text-decoration: none; }
.site-header .brand img { width: 28px; height: 28px; }
.site-header nav { display: flex; gap: 14px; font-size: 14px; flex-wrap: wrap; }
.site-header nav a[aria-current="page"] { font-weight: bold; color: var(--text); text-decoration: none; }

main { max-width: 760px; margin: 0 auto; padding: 0 20px 48px; }
.breadcrumb { font-size: 13px; color: var(--muted); margin: 12px 0 0; }
.breadcrumb a { color: var(--muted); }

h1 { font-size: 26px; line-height: 1.5; margin: 20px 0 8px; }
h2 { font-size: 20px; margin: 36px 0 10px; padding-bottom: 6px; border-bottom: 1px solid var(--border); }
h3 { font-size: 16px; margin: 24px 0 6px; }
p, li { margin: 8px 0; }
ul, ol { padding-left: 24px; }
.lead { color: var(--muted); }

table { border-collapse: collapse; width: 100%; margin: 12px 0; font-size: 15px; }
th, td { border: 1px solid var(--border); padding: 6px 10px; text-align: left; vertical-align: top; }
th { background: var(--panel); white-space: nowrap; }

.note { background: var(--panel); border: 1px solid var(--border); border-left: 4px solid var(--accent); border-radius: 6px; padding: 12px 16px; margin: 16px 0; }
.note p:first-child { margin-top: 0; }
.note p:last-child { margin-bottom: 0; }

.cta { display: inline-block; background: var(--accent); color: #fff; text-decoration: none; border-radius: 8px; padding: 12px 24px; font-weight: bold; margin: 8px 0; }
.cta:hover { opacity: .9; }

.faq-item { border-bottom: 1px solid var(--border); padding-bottom: 8px; }
.steps { counter-reset: step; list-style: none; padding: 0; }
.steps > li { counter-increment: step; position: relative; padding-left: 40px; margin: 18px 0; }
.steps > li::before {
  content: counter(step);
  position: absolute; left: 0; top: 2px;
  width: 26px; height: 26px; border-radius: 50%;
  background: var(--accent); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 14px; font-weight: bold;
}

.site-footer { border-top: 1px solid var(--border); background: var(--panel); margin-top: 40px; }
.site-footer .inner { max-width: 760px; margin: 0 auto; padding: 20px; font-size: 13px; color: var(--muted); }
.site-footer nav { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 8px; }

@media (max-width: 600px) {
  body { font-size: 15px; }
  h1 { font-size: 22px; }
  h2 { font-size: 18px; }
  table { font-size: 14px; }
}