:root {
  --fg: #1a1a1a;
  --muted: #666;
  --accent: #764ba2;
  --line: #e2e2e8;
  --bg: #fafafa;
  --tbd-bg: #fff3cd;
  --tbd-fg: #8a6d00;
}

* { box-sizing: border-box; }

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Kaku Gothic ProN",
    "Hiragino Sans", Meiryo, Roboto, sans-serif;
  color: var(--fg);
  background: var(--bg);
  line-height: 1.9;
  margin: 0;
  font-size: 16px;
}

.wrap {
  max-width: 820px;
  margin: 0 auto;
  padding: 2.5rem 1.25rem 4rem;
}

header.doc {
  text-align: center;
  margin-bottom: 2.5rem;
}

h1 {
  font-size: 1.6rem;
  line-height: 1.5;
  margin: 0 0 0.5rem;
}

.lead {
  margin: 1.5rem 0 2rem;
  color: #333;
}

h2 {
  font-size: 1.15rem;
  text-align: center;
  margin: 3rem 0 1.5rem;
  padding-bottom: 0;
  letter-spacing: 0.1em;
}

h3 {
  font-size: 1.05rem;
  margin: 2.2rem 0 0.6rem;
  padding-left: 0.6rem;
  border-left: 4px solid var(--accent);
}

p { margin: 0.6rem 0; }

ol, ul { margin: 0.4rem 0; padding-left: 1.6rem; }
li { margin: 0.3rem 0; }

ol.paren { list-style: none; padding-left: 1.8rem; counter-reset: item; }
ol.paren > li { position: relative; }
ol.paren > li::before {
  counter-increment: item;
  content: "(" counter(item) ")";
  position: absolute;
  left: -1.8rem;
}

ol.num { padding-left: 1.8rem; }

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

.tbd {
  /* マーカー表示は無効化。プレースホルダーは通常テキストとして表示 */
  color: inherit;
  background: none;
}

.notice {
  background: #eef4ff;
  border: 1px solid #c9d8f5;
  color: #2c4a8a;
  border-radius: 8px;
  padding: 0.9rem 1.1rem;
  margin: 0 0 2rem;
  font-size: 0.9rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 0.95rem;
}
th, td {
  border: 1px solid var(--line);
  padding: 0.6rem 0.8rem;
  text-align: left;
  vertical-align: top;
}
th { background: #f3f0f8; white-space: nowrap; }

.date {
  text-align: right;
  margin-top: 3rem;
  color: var(--muted);
}

footer.doc {
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  font-size: 0.9rem;
  color: var(--muted);
}
footer.doc nav a { margin-right: 1.2rem; display: inline-block; }
footer.doc .copy { margin-top: 1rem; }

@media (max-width: 600px) {
  body { font-size: 15px; }
  .wrap { padding: 1.75rem 1rem 3rem; }
  h1 { font-size: 1.35rem; }
}