/* ===========================
   大人数ビンゴ抽選 — yorozu-craft 共通の和紙風の配色
   色はトークン（--bg / --card / --text / --muted / --accent / --border）だけを使う。
   ダークモードは端末の設定に自動で合わせる（prefers-color-scheme。手動切替は付けない）
   =========================== */
:root {
  color-scheme: light dark;
  --bg: #f0ebe0;
  --bg-2: #e6dfd0;
  --card: #faf6ee;
  --text: #3a3025;
  --muted: #6e604f;
  --accent: #8b4513;
  --accent-soft: #f3e6d8;
  --border: #cfc0a0;
  --shadow: rgba(58, 48, 37, 0.12);
  --ok: #2f6b2f;
  --ok-soft: #e3f0dc;
  --warn: #9a3412;
  --hit: #f6d68a;
  /* ボールの色（B・I・N・G・O）。文字は --ball-text で読みやすく */
  --col-B: #2f62b0;
  --col-I: #b3332e;
  --col-N: #6b6b6b;
  --col-G: #2f7d3a;
  --col-O: #b8860b;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1c1814;
    --bg-2: #25201a;
    --card: #2b251e;
    --text: #ece4d6;
    --muted: #b9ab96;
    --accent: #e0a066;
    --accent-soft: #3a2e22;
    --border: #4a3f33;
    --shadow: rgba(0, 0, 0, 0.4);
    --ok: #9fd49a;
    --ok-soft: #22341f;
    --warn: #f0a37a;
    --hit: #6b5320;
  }
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
[hidden] { display: none !important; }

body {
  /* README「ツールを追加するとき」9: 端末のフォント。Web フォントは読まない */
  font-family: "Noto Sans JP", "Noto Sans CJK JP", "Hiragino Sans", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}

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

/* ヘッダー */
.app-header {
  text-align: center;
  padding: 1.4rem 1rem 1.1rem;
  background: var(--bg-2);
  border-bottom: 2px solid var(--border);
}
.app-header h1 { font-size: 1.45rem; color: var(--accent); line-height: 1.4; }
.app-header .subtitle { font-size: 0.88rem; color: var(--muted); margin-top: 0.3rem; }

/* レイアウト */
.app-main { max-width: 680px; margin: 0 auto; padding: 1rem; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.2rem;
  margin-bottom: 1rem;
  box-shadow: 0 2px 8px var(--shadow);
}
.card h2 {
  font-size: 1.02rem;
  color: var(--accent);
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.4rem;
  margin-bottom: 0.9rem;
}

/* 入力 */
.field { margin-bottom: 1rem; }
.field label { display: block; font-weight: 600; font-size: 0.95rem; margin-bottom: 0.25rem; }
.field .hint { font-size: 0.8rem; color: var(--muted); margin-bottom: 0.4rem; }
.field input[type="number"], .field input[type="text"], .field select {
  width: 100%;
  max-width: 16rem;
  padding: 0.45rem 0.5rem;
  font-size: 1rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--card);
  color: var(--text);
}

.btn {
  display: inline-block;
  padding: 0.5rem 1.1rem;
  border: none;
  border-radius: 6px;
  background: var(--accent);
  color: var(--card);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
}
.btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* 読みもの（guide.html） */
.content h3 { font-size: 0.95rem; margin: 1rem 0 0.3rem; }
.content p, .content li { font-size: 0.9rem; }
.content p + p { margin-top: 0.5rem; }
.content ul, .content ol { padding-left: 1.3rem; margin: 0.3rem 0; }
.faq dt { font-weight: 600; margin-top: 0.9rem; font-size: 0.92rem; }
.faq dt::before { content: 'Q. '; color: var(--accent); }
.faq dd { font-size: 0.88rem; color: var(--muted); padding: 0.2rem 0 0.5rem 1.2rem; border-bottom: 1px solid var(--border); }
.info-list { display: grid; grid-template-columns: max-content 1fr; gap: 0.4rem 1.2rem; font-size: 0.9rem; }
.info-list dt { font-weight: 600; }
.info-list dd { color: var(--muted); }
.small { font-size: 0.8rem; color: var(--muted); margin-top: 0.4rem; }

/* フッター */
.app-footer {
  text-align: center;
  padding: 1rem;
  font-size: 0.78rem;
  color: var(--muted);
  border-top: 1px solid var(--border);
  margin-top: 0.5rem;
}
.footer-nav ul { list-style: none; display: flex; justify-content: center; flex-wrap: wrap; gap: 0.4rem 1.1rem; margin-bottom: 0.6rem; }
.footer-nav a { color: var(--muted); text-decoration: none; }
.footer-nav a:hover, .footer-nav a[aria-current="page"] { color: var(--accent); }

@media (max-width: 480px) {
  .app-header h1 { font-size: 1.2rem; }
}

/* ===========================
   ビンゴ（抽選ページ・カードページ）
   =========================== */
.visually-hidden { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.app-main.wide { max-width: 1100px; }
.hint { font-size: 0.82rem; color: var(--muted); margin-bottom: 0.6rem; }
.label-like { font-weight: 600; font-size: 0.95rem; margin-bottom: 0.25rem; }
.btn { margin: 0.15rem 0.2rem 0.15rem 0; text-decoration: none; }
.btn:disabled { opacity: 0.5; cursor: default; }
.btn-ghost { background: transparent; color: var(--accent); border: 1px solid var(--accent); }
.field textarea, .inline-form input[type="text"], .field input[type="text"] {
  width: 100%; padding: 0.45rem 0.5rem; font-size: 1rem; border: 1px solid var(--border); border-radius: 6px;
  background: var(--card); color: var(--text); font-family: inherit;
}
.inline-form { display: flex; gap: 0.4rem; align-items: center; margin: 0.4rem 0; }
.inline-form input[type="text"] { flex: 1; min-width: 0; }
.inline-form .btn { flex: none; margin: 0; }
.grid-2 { display: grid; grid-template-columns: 1fr; gap: 0 1rem; }
@media (min-width: 900px) { .grid-2 { grid-template-columns: 1fr 1fr; } }
.check-label { font-weight: 400 !important; display: flex !important; gap: 0.4rem; align-items: center; }
.bulk { margin-top: 0.5rem; font-size: 0.9rem; }
.bulk summary { cursor: pointer; color: var(--accent); }
.bulk textarea { width: 100%; margin: 0.4rem 0; padding: 0.4rem; font-size: 0.95rem; border: 1px solid var(--border); border-radius: 6px; background: var(--card); color: var(--text); font-family: inherit; }
.seed { font-size: 1.3rem; letter-spacing: 0.15em; font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace; }
.est-inputs { display: flex; flex-wrap: wrap; gap: 0 1rem; }
.est-inputs .field { flex: 1 1 9rem; }
.est-inputs .field input, .est-inputs .field select { max-width: 100%; }
.est-result p { font-size: 0.92rem; margin-top: 0.4rem; }
.est-result p:first-child { font-weight: 600; }
.banner { background: var(--accent-soft); display: flex; flex-wrap: wrap; gap: 0.5rem; align-items: center; }
.banner span { flex: 1 1 18rem; font-size: 0.9rem; }

/* --- 抽選とカード印刷の切り替え（両ページの main の先頭。静的な HTML なので読み込み後にずれない） --- */
.mode-switch { display: flex; max-width: 30rem; margin: 0 auto 1rem; border: 1px solid var(--accent); border-radius: 999px; overflow: hidden; background: var(--card); }
.mode-switch a { flex: 1 1 auto; text-align: center; white-space: nowrap; padding: 0.5rem 0.7rem; font-size: 0.9rem; font-weight: 600; color: var(--accent); text-decoration: none; }
.mode-switch a + a { border-left: 1px solid var(--accent); }
.mode-switch a[aria-current="page"] { background: var(--accent); color: var(--card); }
.mode-switch a:not([aria-current]):hover { background: var(--accent-soft); }
.mode-switch a:focus-visible { outline: 2px solid var(--accent); outline-offset: -4px; }
.mode-switch a[aria-current="page"]:focus-visible { outline-color: var(--card); }
body.is-max .mode-switch { display: none; }

/* --- 抽選 --- */
.stage { padding: 0.9rem; }
.stage-bar { display: flex; flex-wrap: wrap; align-items: center; gap: 0.3rem 0.8rem; border-bottom: 1px solid var(--border); padding-bottom: 0.5rem; margin-bottom: 0.6rem; }
.stage .stage-title { border: 0; margin: 0; padding: 0; font-size: 1.02rem; }
.stage-count { font-weight: 600; font-variant-numeric: tabular-nums; }
.stage-tools { margin-left: auto; display: flex; gap: 0.3rem; flex-wrap: wrap; }
.icon-btn { font: inherit; font-size: 0.82rem; padding: 0.3rem 0.6rem; border-radius: 999px; border: 1px solid var(--border); background: var(--card); color: var(--muted); cursor: pointer; }
.icon-btn[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: var(--card); }
.icon-btn[aria-pressed="false"]#btn-sound, .icon-btn[aria-pressed="false"]#btn-voice { text-decoration: line-through; }
.stage-body { display: grid; grid-template-columns: 1fr; gap: 1rem; }
@media (min-width: 900px) { .stage-body { grid-template-columns: minmax(300px, 2fr) 3fr; align-items: start; } }
.ball-area { text-align: center; }
.ball {
  --ball: var(--accent);
  width: min(62vw, 15rem); aspect-ratio: 1; margin: 0.3rem auto 0.6rem; border-radius: 50%;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  background: var(--ball);
  box-shadow: inset -0.6rem -0.8rem 1.4rem rgba(0, 0, 0, 0.28), 0 0.3rem 0.9rem var(--shadow);
  color: #fff; line-height: 1;
}
.ball[data-col="B"] { --ball: var(--col-B); }
.ball[data-col="I"] { --ball: var(--col-I); }
.ball[data-col="N"] { --ball: var(--col-N); }
.ball[data-col="G"] { --ball: var(--col-G); }
.ball[data-col="O"] { --ball: var(--col-O); }
.ball-letter { font-size: 2rem; font-weight: 800; min-height: 2rem; margin-bottom: 0.2rem; }
.ball-num {
  font-size: 6.2rem; font-weight: 800; font-variant-numeric: tabular-nums; letter-spacing: -0.03em;
  background: #fff; color: #222; border-radius: 50%; width: 62%; aspect-ratio: 1; display: flex; align-items: center; justify-content: center;
}
.ball-num { font-size: clamp(3.4rem, 20vw, 6.2rem); }
.ball.spinning .ball-num { color: #777; }
.ball.pop { animation: pop 0.45s ease-out; }
@keyframes pop { 0% { transform: scale(0.7); } 60% { transform: scale(1.08); } 100% { transform: scale(1); } }
@media (prefers-reduced-motion: reduce) { .ball.pop { animation: none; } }
.batch { font-size: 1.5rem; font-weight: 700; margin-bottom: 0.4rem; font-variant-numeric: tabular-nums; }
.btn-draw { font-size: 1.35rem; padding: 0.8rem 2.2rem; border-radius: 999px; min-width: 12rem; margin: 0; }
.draw-hint { font-size: 0.78rem; color: var(--muted); margin-top: 0.3rem; }
.sub-row { display: flex; flex-wrap: wrap; justify-content: center; align-items: center; gap: 0.4rem 1rem; margin-top: 0.6rem; }
.next-prize { font-weight: 600; font-size: 0.95rem; }
.set-status { margin-top: 0.5rem; font-weight: 600; color: var(--accent); }
.history-title { font-size: 0.95rem; margin-bottom: 0.2rem; }
.recent { font-size: 0.9rem; color: var(--muted); margin-bottom: 0.5rem; font-variant-numeric: tabular-nums; min-height: 1.5em; }
.board { display: flex; flex-direction: column; gap: 0.3rem; min-height: 10.6rem; }  /* 1〜75 の 5 行分を先に確保（読み込み時のずれを防ぐ） */
.board-row { display: flex; gap: 0.3rem; align-items: flex-start; }
.board-letter { flex: none; width: 1.9rem; height: 1.9rem; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: 800; color: #fff; }
.board-row:nth-child(1) .board-letter { background: var(--col-B); }
.board-row:nth-child(2) .board-letter { background: var(--col-I); }
.board-row:nth-child(3) .board-letter { background: var(--col-N); }
.board-row:nth-child(4) .board-letter { background: var(--col-G); }
.board-row:nth-child(5) .board-letter { background: var(--col-O); }
.board-cells { display: flex; flex-wrap: wrap; gap: 0.2rem; flex: 1; min-width: 0; }
.cell {
  width: 1.9rem; height: 1.9rem; display: inline-flex; align-items: center; justify-content: center;
  font-size: 0.82rem; font-variant-numeric: tabular-nums; border-radius: 4px; border: 1px solid var(--border); color: var(--muted);
}
.cell.on { background: var(--accent); border-color: var(--accent); color: var(--card); font-weight: 700; }
.cell.last { outline: 3px solid var(--hit); outline-offset: 1px; }
@media (max-width: 600px) {
  .stage-tools { margin-left: 0; }
  .board-letter { width: 1.35rem; height: 1.35rem; font-size: 0.75rem; }
  .board-row { gap: 0.2rem; }
  .board { min-height: 7.95rem; }
  .board--bingo .board-cells { display: grid; grid-template-columns: repeat(var(--cols, 15), minmax(0, 1fr)); gap: 2px; }
  .board--bingo .cell { width: auto; height: 1.35rem; font-size: 0.68rem; border-radius: 3px; }
}

/* 全画面（プロジェクター）: 暗い背景で数字を最大に */
.stage.is-full {
  --card: #14110e; --text: #f5efe4; --muted: #c9bba6; --border: #3d342a; --accent: #f0b070; --hit: #ffd84d;
  background: var(--card); color: var(--text); margin: 0; border: 0; border-radius: 0; box-shadow: none;
  width: 100vw; height: 100vh; height: 100dvh; overflow: auto; padding: 1.5vh 2vw; display: flex; flex-direction: column;
}
body.is-max { overflow: hidden; }
body.is-max .stage.is-full { position: fixed; inset: 0; z-index: 100; }
.stage.is-full .stage-bar { font-size: clamp(1rem, 2.2vh, 1.6rem); }
.stage.is-full .stage-count { font-size: clamp(1.1rem, 3vh, 2.2rem); }
.stage.is-full .stage-body { flex: 1; grid-template-columns: 1fr; align-items: center; }
@media (min-aspect-ratio: 1/1) { .stage.is-full .stage-body { grid-template-columns: 1fr 1.25fr; } }
.stage.is-full .ball { width: min(58vh, 44vw); }
.stage.is-full .ball-letter { font-size: min(7vh, 5vw); min-height: min(7vh, 5vw); }
.stage.is-full .ball-num { font-size: min(22vh, 16vw); }
.stage.is-full .batch { font-size: min(6vh, 4vw); }
.stage.is-full .draw-hint { display: none; }
.stage.is-full .next-prize, .stage.is-full .set-status { font-size: min(3.4vh, 2.4vw); }
.stage.is-full .recent { font-size: min(3vh, 2vw); }
.stage.is-full .history-title { font-size: min(3vh, 2vw); }
.stage.is-full .cell, .stage.is-full .board-letter { width: min(5.4vh, 3.4vw); height: min(5.4vh, 3.4vw); font-size: min(2.8vh, 1.8vw); }

/* --- 照合 --- */
.check-result p { margin: 0.4rem 0; }
.check-result .ok { color: var(--ok); background: var(--ok-soft); padding: 0.4rem 0.6rem; border-radius: 6px; font-weight: 700; }
.check-result .big { font-size: 1.05rem; }
.check-result .no { font-weight: 600; }
.check-result .warn { color: var(--warn); font-size: 0.9rem; }
.mini-card { border-collapse: collapse; margin: 0.5rem 0; font-variant-numeric: tabular-nums; }
.mini-card th, .mini-card td { width: 2.4rem; height: 2.1rem; text-align: center; border: 1px solid var(--border); font-size: 0.95rem; }
.mini-card th { background: var(--accent); color: var(--card); }
.mini-card td.hit { background: var(--accent-soft); font-weight: 700; }
.mini-card td.line { background: var(--hit); }

/* --- 景品 --- */
.prize-list { list-style: none; padding: 0; }
.prize-no { font-weight: 700; min-width: 1.6rem; text-align: right; }
.prize { margin: 0.3rem 0; display: flex; flex-wrap: wrap; gap: 0.3rem; align-items: center; }
.prize input { font: inherit; font-size: 0.92rem; padding: 0.3rem 0.4rem; border: 1px solid var(--border); border-radius: 5px; background: var(--card); color: var(--text); }
.prize .prize-name { flex: 3 1 10rem; min-width: 0; }
.prize .prize-winner { flex: 2 1 6rem; min-width: 0; }
.prize.is-next .prize-name { border-color: var(--accent); border-width: 2px; }
.prize.is-done .prize-name { text-decoration: line-through; color: var(--muted); }
.prize-tools { white-space: nowrap; }
.mini-btn { font: inherit; font-size: 0.85rem; width: 1.8rem; height: 1.8rem; border: 1px solid var(--border); border-radius: 5px; background: var(--card); color: var(--text); cursor: pointer; }
.mini-btn:disabled { opacity: 0.35; }
.summary-text { white-space: pre-wrap; font-family: inherit; font-size: 0.9rem; background: var(--bg); border: 1px solid var(--border); border-radius: 6px; padding: 0.6rem; margin: 0.6rem 0; }
.next-links { list-style: none; margin-top: 0.8rem; font-size: 0.92rem; }
.next-links li { margin: 0.2rem 0; }

/* --- カード（印刷） --- */
#sheet-info { min-height: 1.7em; }  /* 枚数とページ数は JS で入る。1 行分を先に確保（印刷ボタンが下にずれないように） */
#c-tag { margin-left: 0.4em; }  /* 空白の文字を置かない（JS で文字が入ったときに空白がずれて CLS に数えられる） */
.sheets { --z: 0.45; margin: 0.6rem 0 1rem; overflow-x: auto; }
.sheet {
  zoom: var(--z); width: 210mm; height: 297mm; margin: 0 auto 24px; background: #fff; color: #111;
  box-shadow: 0 1px 6px rgba(0, 0, 0, 0.25); display: grid; padding: 8mm;
}
.sheet--4 { grid-template-columns: 1fr 1fr; grid-template-rows: 1fr 1fr; }
.sheet--2 { grid-template-columns: 1fr; grid-template-rows: 1fr 1fr; }
.slot { display: flex; align-items: center; justify-content: center; border: 0 dashed #999; min-width: 0; min-height: 0; }
.sheet--4 .slot:nth-child(odd) { border-right-width: 0.3mm; }
.sheet--4 .slot:nth-child(-n+2), .sheet--2 .slot:nth-child(1) { border-bottom-width: 0.3mm; }
.bcard { width: 88mm; font-family: "Noto Sans JP", "Noto Sans CJK JP", "Hiragino Sans", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif; }
.sheet--2 .bcard { width: 118mm; }
.bcard-title { text-align: center; font-weight: 700; font-size: 12pt; margin-bottom: 1.5mm; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bcard-grid { border-collapse: collapse; width: 100%; table-layout: fixed; }
.bcard-grid th { background: #222; color: #fff; font-size: 20pt; font-weight: 800; height: 12mm; border: 0.4mm solid #222; }
.bcard-grid td { height: 17.5mm; text-align: center; border: 0.4mm solid #222; font-size: 22pt; font-weight: 700; font-variant-numeric: tabular-nums; color: #111; }
.sheet--2 .bcard-grid th { height: 15mm; font-size: 26pt; }
.sheet--2 .bcard-grid td { height: 20mm; font-size: 30pt; }
.bcard-grid td.free { font-size: 12pt; background: #eee; letter-spacing: 0.05em; }
.bcard-foot { display: flex; justify-content: space-between; align-items: baseline; margin-top: 1.5mm; gap: 2mm; }
.bcard-no { font-weight: 800; font-size: 13pt; letter-spacing: 0.05em; font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace; }
.bcard-credit { font-size: 7pt; color: #444; }

/* US Letter（215.9 × 279.4 mm）。A4 より 17.6 mm 低いので、2 枚のときはマスを少し低くして 1 ページに収める */
.sheet--letter { width: 215.9mm; height: 279.4mm; }
.sheet--letter.sheet--2 .bcard-grid th { height: 14mm; }
.sheet--letter.sheet--2 .bcard-grid td { height: 18mm; }

/* 見本は 1 ページ目だけ（SCREEN.md 1.2「見本（縮小 1 枚）」）。印刷ではすべてのページを出す */
@media screen { .sheets:not(.show-all) .sheet:nth-child(n+2) { display: none; } }
.preview-more { text-align: center; margin: -0.4rem 0 1rem; }

/* 用紙の大きさ（@page）は cards.js が <style id="page-size"> で上書きする（A4 かレター）。これは JS が動かないときの既定 */
@page { size: A4 portrait; margin: 0; }
@media print {
  body { background: #fff; }
  .app-header, .app-footer, .mode-switch, .fixbar, .app-main > :not(.sheets), ins.adsbygoogle, .adsbygoogle, .google-auto-placed, iframe { display: none !important; }
  .app-main { max-width: none; padding: 0; margin: 0; }
  .sheets { margin: 0; overflow: visible; }
  .sheets .sheet { zoom: 1; margin: 0; box-shadow: none; height: 296.6mm; break-after: page; page-break-after: always; }
  .sheets .sheet--letter { height: 279.1mm; }
  .sheets .sheet:last-child { break-after: auto; page-break-after: auto; }
}

/* 画面の部品（yorozu-template の style.css と同じ。SCREEN.md） */
fieldset.plain { border: 0; padding: 0; margin: 0; min-width: 0; }
details.card.opt { padding: 0 1.2rem; margin-bottom: 1rem; }
details.card.opt > summary {
  cursor: pointer; display: block; min-height: 44px; padding: 0.6rem 0;
  color: var(--accent); font-weight: 600; font-size: 0.95rem; list-style: none;
}
details.card.opt > summary::-webkit-details-marker { display: none; }
details.card.opt > summary::before { content: '▸'; margin-right: 0.4rem; }
details.card.opt[open] > summary::before { content: '▾'; }
details.card.opt[open] { padding-bottom: 0.9rem; }
details.card.opt[open] > summary { border-bottom: 1px solid var(--border); margin-bottom: 0.9rem; }
details > summary:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.opt-state { color: var(--text); font-weight: normal; }
.btn-row { display: flex; flex-wrap: wrap; gap: 0.6rem; margin: 0.6rem 0 0.8rem; }
.btn-row .btn { min-height: 44px; margin: 0; }
#btn-print { min-width: 10rem; font-size: 1.05rem; }
.lang-switch { font-size: 0.82rem; margin-top: 0.35rem; }

/* 上端の固定バー（SCREEN.md 1.2・D59）: 印刷ボタンが画面の外にあるときだけ。下端は AdSense のアンカー広告が使う */
.fixbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50; height: 44px;
  display: flex; align-items: center; justify-content: center; gap: 0.8rem; padding: 0 1rem;
  background: var(--card); border-bottom: 2px solid var(--accent); box-shadow: 0 2px 8px var(--shadow);
}
.fixbar-type { font-size: 0.85rem; color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; min-width: 0; }
.fixbar .btn { flex: none; padding: 0.2rem 1.1rem; height: 34px; margin: 0; }

/* 使い方ページの折りたたみ（WRITING.md の基準で、補足・一覧はここに入れる） */
.content details { margin: 0.4rem 0; }
.content summary { cursor: pointer; color: var(--accent); font-size: 0.88rem; }
.content details[open] summary { margin-bottom: 0.3rem; }
.content h4 { font-size: 0.9rem; margin: 0.8rem 0 0.2rem; }