/* ずんだもんドリル：教室テーマ（黒板のヘッダー＋ノートの問題用紙） */
:root {
  --accent: #B8359B;        /* 本ごとの色（色チョーク）。build.py が上書きする */
  --accent-dark: #5A1456;
  --board: #2E5A45;         /* 黒板 */
  --board-deep: #244A39;
  --frame: #8B5A2B;         /* 黒板の木枠 */
  --chalk: #F4F1E6;
  --chalk-yellow: #F6D56A;
  --paper: #FBF9F1;         /* 教室の机（ページ背景） */
  --sheet: #FFFFFF;         /* ノートの紙 */
  --rule: #DCE8E1;          /* ノートの罫線 */
  --margin-line: #F2A5C0;   /* ノートの赤い縦線 */
  --sheet-edge: #E7E2D3;
  --text: #2B2A26;
  --muted: #5F6E66;
  --line: #BFC9C0;
  --ok: #4CAF7A;
  --ok-bg: #EAF6EE;
  --ng: #E07A6A;
  --ng-bg: #FCEDEA;
  --note-bg: #FFF6C9;       /* 付箋 */
  --accent-text: var(--accent);   /* 文字・線に使う本の色（ダークでは明るめ） */
  --font-sans: "Zen Kaku Gothic New", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", Meiryo, sans-serif;
  --font-chalk: "Yusei Magic", "Zen Kaku Gothic New", "Hiragino Sans", sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #1E201D;
    --sheet: #272A26;
    --rule: #333A34;
    --margin-line: #8E5A6C;
    --sheet-edge: #353933;
    --text: #ECEAE0;
    --muted: #A9B3AB;
    --line: #4C554E;
    --ok-bg: #1F3A2B;
    --ng-bg: #3F2422;
    --note-bg: #3A3420;
    --accent-text: color-mix(in srgb, var(--accent) 60%, #FFFFFF);
    color-scheme: dark;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: var(--font-sans);
  line-height: 1.75;
  -webkit-text-size-adjust: 100%;
}
a { color: var(--accent-text); }
button { font: inherit; cursor: pointer; }
button:focus-visible, a:focus-visible, input:focus-visible, textarea:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }

/* 黒板 */
.header {
  position: relative;
  background: radial-gradient(ellipse at 30% 20%, var(--board), var(--board-deep) 70%);
  color: var(--chalk);
  padding: 26px 16px 0;
  border-bottom: 14px solid var(--frame);
  overflow: hidden;
}
.header::after {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background: repeating-linear-gradient(115deg, transparent 0 6px, rgba(255,255,255,.025) 6px 7px);
}
.header-inner {
  max-width: 760px; margin: 0 auto;
  display: grid; grid-template-columns: 1fr auto; gap: 12px; align-items: end;
}
.header-text { padding-bottom: 20px; min-width: 0; }
.header p { margin: 0; }
.book { font-family: var(--font-chalk); color: var(--chalk-yellow); font-size: 15px; letter-spacing: .04em; }
.book a { color: inherit; }
h1 {
  font-family: var(--font-chalk); font-weight: 400; font-size: 30px; line-height: 1.35; margin: 4px 0 10px;
  text-shadow: 0 0 1px rgba(255,255,255,.35); text-wrap: balance;
}
.lead { font-size: 13px; opacity: .88; }
.lead a { color: var(--chalk); }
.header-chara { width: 118px; height: auto; margin-bottom: -6px; filter: drop-shadow(0 4px 6px rgba(0,0,0,.35)); align-self: end; position: relative; z-index: 1; }

/* 進捗（黒板の下の帯） */
#score-slot { position: sticky; top: 0; z-index: 10; }
.score {
  background: color-mix(in srgb, var(--paper) 90%, transparent);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--sheet-edge);
}
.score-inner {
  max-width: 760px; margin: 0 auto; padding: 10px 16px;
  display: flex; gap: 8px; align-items: center; font-size: 13px; font-weight: 700; color: var(--muted);
}
.score .segs { flex: 1; display: flex; gap: 5px; }
.score .seg { flex: 1; height: 8px; border-radius: 4px; background: var(--rule); }
.score .seg.ok { background: var(--ok); }
.score .seg.ng { background: var(--ng); }
.score .seg.essay { background: var(--accent); opacity: .6; }
.score .count { font-variant-numeric: tabular-nums; white-space: nowrap; }

main, .footer { max-width: 760px; margin: 0 auto; }
main { padding: 16px; display: grid; gap: 18px; }

/* ノートの問題用紙 */
.card {
  position: relative;
  background: var(--sheet);
  background-image: repeating-linear-gradient(transparent 0 31px, var(--rule) 31px 32px);
  background-size: 100% 32px;
  border: 1px solid var(--sheet-edge);
  border-radius: 6px;
  padding: 16px 20px 16px 50px;
  box-shadow: 0 2px 0 var(--sheet-edge), 0 6px 14px rgba(60,60,40,.06);
}
.card::before { content: ""; position: absolute; top: 0; bottom: 0; left: 34px; width: 1px; background: var(--margin-line); opacity: .7; }
.card-head { position: absolute; left: 0; top: 14px; width: 34px; display: flex; flex-direction: column; align-items: center; gap: 6px; }
.qno { font-family: var(--font-chalk); font-size: 17px; line-height: 1; color: var(--accent-text); }
.qtype { font-size: 10px; font-weight: 700; color: var(--muted); border: 1.5px solid var(--line); border-radius: 4px; padding: 3px 0; line-height: 1.3; writing-mode: vertical-rl; letter-spacing: .1em; }
.question { margin: 0 0 12px; font-size: 16.5px; font-weight: 700; line-height: 32px; }

.choices { display: grid; gap: 8px; }
.choices.tf { grid-template-columns: 1fr 1fr; }
.choices.tf .choice { font-size: 26px; padding: 6px; text-align: center; }
.choice {
  text-align: left; padding: 9px 12px; font-size: 15px; border-radius: 6px;
  background: color-mix(in srgb, var(--sheet) 70%, transparent); color: var(--text);
  border: 1.5px dashed var(--line);
  transition: border-color .15s, background .15s;
}
.choice:hover:not(:disabled) { border-color: var(--accent); border-style: solid; }
.choice:disabled { cursor: default; opacity: .55; }
.choice.is-answer { border-style: solid; border-color: var(--ok); background: var(--ok-bg); opacity: 1; }
.choice.is-correct { border-style: solid; border-color: var(--ok); background: var(--ok-bg); opacity: 1; font-weight: 700; }
.choice.is-correct::before { content: "◯ "; color: var(--ok); }
.choice.is-wrong { border-style: solid; border-color: var(--ng); background: var(--ng-bg); opacity: 1; }
.choice.is-wrong::before { content: "✕ "; color: var(--ng); }
.choices.tf .choice::before { content: none; }

.fill { display: flex; gap: 10px; flex-wrap: wrap; }
.fill-input, .essay-input {
  font: inherit; font-size: 16px; color: var(--text); background: var(--sheet);
  border: 1.5px dashed var(--line); border-radius: 6px; padding: 9px 12px;
}
.fill-input { flex: 1 1 200px; min-width: 0; }
.fill-input:focus, .essay-input:focus { border-style: solid; border-color: var(--accent); outline: none; }
.fill-input.is-correct { border-style: solid; border-color: var(--ok); background: var(--ok-bg); }
.fill-input.is-wrong { border-style: solid; border-color: var(--ng); background: var(--ng-bg); }
.essay-input { width: 100%; resize: vertical; margin-bottom: 10px; line-height: 1.7; }
.primary, .button {
  display: inline-block; text-decoration: none; border-radius: 6px;
  background: var(--accent); color: #fff; border: none; padding: 9px 16px; font-weight: 700; font-size: 14px;
}
.primary:disabled { opacity: .45; cursor: default; }
.button.secondary { background: transparent; color: var(--accent-text); border: 1.5px dashed var(--accent-text); }
.answer-note { margin: 10px 0 0; font-weight: 700; color: var(--ng); }

/* 付箋（めたんの解説） */
.explain {
  display: flex; gap: 12px; align-items: flex-start;
  margin-top: 12px; padding: 10px 12px; border-radius: 10px; background: var(--note-bg);
  font-size: 14px; line-height: 1.65;
  box-shadow: 0 2px 4px rgba(60,60,40,.08);
}
.explain.ok { background: var(--ok-bg); }
.explain.ng { background: var(--ng-bg); }
.explain .icon { width: 52px; height: 52px; object-fit: cover; object-position: top; border-radius: 50%; background: #fff; flex: none; }
.explain-body { min-width: 0; }
.explain-body p { margin: 0 0 4px; }
.verdict { font-weight: 800; color: var(--board); }
.explain.ok .verdict { color: var(--ok); }
.explain.ng .verdict { color: var(--ng); }
.ref { font-size: 14px; color: var(--accent-text); font-weight: 700; }

.model { margin-top: 12px; padding: 10px 14px; border-left: 4px solid var(--accent); background: color-mix(in srgb, var(--accent) 7%, var(--sheet)); border-radius: 0 8px 8px 0; }
.model p { margin: 0; font-size: 15px; }
.model-title, .points-title { font-weight: 800; color: var(--accent-text); margin-bottom: 4px !important; }
.points { margin-top: 12px; }
.points-title { margin: 0 0 6px; font-size: 14px; }
.point { display: flex; gap: 8px; align-items: flex-start; font-size: 15px; margin: 4px 0; cursor: pointer; }
.point input { margin-top: 6px; width: 18px; height: 18px; accent-color: var(--accent); flex: none; }

/* 結果（小さな黒板） */
.result {
  display: grid; grid-template-columns: auto 1fr; gap: 16px; align-items: center;
  background: var(--board); color: var(--chalk); border-radius: 10px; padding: 16px 18px;
  border-bottom: 8px solid var(--frame);
}
.result[hidden] { display: none; }
.result-chara { width: 100px; height: auto; }
.result-body { min-width: 0; }
.result-score { margin: 0; font-family: var(--font-chalk); font-size: 28px; color: var(--chalk-yellow); line-height: 1.3; }
.result-msg { margin: 4px 0 4px; font-weight: 700; font-size: 15px; }
.result-missed { margin: 0 0 8px; font-size: 13px; opacity: .85; }
.result-actions { display: flex; gap: 8px; flex-wrap: wrap; }
.result .button { background: var(--chalk); color: var(--board-deep); font-size: 13px; }
.result .button.secondary { background: transparent; color: var(--chalk); border-color: var(--chalk); }

.retry-note { font-size: 13px; color: var(--muted); margin: -4px 0 0; padding: 0 2px; }
.retry-note a { font-weight: 700; }

/* ほかの章へのナビ */
.chapter-nav { max-width: 760px; margin: 0 auto; padding: 0 16px 8px; display: grid; gap: 18px; }
.nav-prevnext { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.nav-link {
  display: flex; flex-direction: column; gap: 2px; min-width: 0;
  padding: 10px 14px; border-radius: 6px; text-decoration: none; color: var(--text);
  background: var(--sheet); border: 1.5px dashed var(--line);
}
.nav-link:hover { border-style: solid; border-color: var(--accent-text); color: var(--accent-text); }
.nav-link.next { text-align: right; }
.nav-link.empty { visibility: hidden; }
.nav-link .dir { font-size: 12px; font-weight: 700; color: var(--accent-text); }
.nav-link .t { font-size: 13.5px; font-weight: 600; line-height: 1.5; overflow-wrap: anywhere; }
.chapter-nav .book-title { font-size: 17px; }
.book-list .current {
  display: flex; justify-content: space-between; gap: 12px; align-items: baseline;
  line-height: 44px; font-weight: 700; color: var(--accent-text); font-size: 15px;
}
.book-list li.is-current .ch { color: var(--accent-text); }
.footer { padding: 8px 16px 40px; font-size: 12px; color: var(--muted); }
.footer a { color: var(--muted); }

@media (max-width: 560px) {
  .header-inner { grid-template-columns: 1fr; }
  .header-chara { display: none; }
  h1 { font-size: 23px; }
  .question { font-size: 15.5px; }
  .card { padding-left: 44px; padding-right: 14px; }
  .card::before { left: 30px; }
  .card-head { width: 30px; }
  .result { grid-template-columns: 1fr; text-align: center; justify-items: center; }
  .result-actions { justify-content: center; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }

/* 一覧ページ（出席簿） */
.book-sheet {
  position: relative; background: var(--sheet);
  background-image: repeating-linear-gradient(transparent 0 43px, var(--rule) 43px 44px);
  background-size: 100% 44px;
  border: 1px solid var(--sheet-edge); border-radius: 6px; padding: 12px 18px 12px 50px;
  box-shadow: 0 2px 0 var(--sheet-edge), 0 6px 14px rgba(60,60,40,.06);
}
.book-sheet::before { content: ""; position: absolute; top: 0; bottom: 0; left: 34px; width: 1px; background: var(--margin-line); opacity: .7; }
.book-title { margin: 0 0 6px; font-family: var(--font-chalk); font-weight: 400; font-size: 20px; line-height: 44px; color: var(--accent-text); }
.book-list { list-style: none; padding: 0; margin: 0; }
.book-list li { position: relative; }
.book-list .ch {
  position: absolute; left: -46px; top: 0; width: 34px; text-align: center; line-height: 44px;
  font-family: var(--font-chalk); font-size: 14px; color: var(--muted);
}
.book-list a {
  display: flex; justify-content: space-between; gap: 12px; align-items: baseline;
  line-height: 44px; color: var(--text); text-decoration: none; font-weight: 600; font-size: 15px;
}
.book-list a:hover { color: var(--accent-text); }
.book-list .n { font-size: 12px; color: var(--muted); white-space: nowrap; font-weight: 500; }
@media (max-width: 560px) {
  .book-sheet { padding-left: 44px; padding-right: 12px; background-image: none; }
  .book-sheet::before { left: 30px; }
  .book-title { line-height: 1.4; margin-bottom: 10px; }
  .book-list .ch { left: -42px; width: 30px; line-height: 1.5; top: 10px; }
  .book-list a, .book-list .current { font-size: 14px; line-height: 1.5; padding: 10px 0; border-bottom: 1px dashed var(--rule); flex-direction: column; gap: 0; }
  .nav-prevnext { grid-template-columns: 1fr; }
  .nav-link.next { text-align: left; }
}