/* =========================================================
   学習用クイズサイト スタイルシート
   テーマ: 試験対策の「解答用紙」をイメージした落ち着いた配色
   ========================================================= */

:root {
  --paper: #faf7f0;
  --paper-line: #e4ddc9;
  --ink: #2b2a25;
  --ink-soft: #6b6656;
  --accent: #1f6f5c;       /* 正解・確定色 (深緑) */
  --accent-soft: #e4f1ec;
  --wrong: #a4463a;        /* 不正解色 (赤茶) */
  --wrong-soft: #f6e9e6;
  --stamp: #b23b2e;        /* 「正解」スタンプの朱色 */
  --card-bg: #ffffff;
  --shadow: 0 1px 2px rgba(43, 42, 37, 0.06), 0 6px 20px rgba(43, 42, 37, 0.06);
  --radius: 10px;
  --serif: "Shippori Mincho", "Noto Serif JP", "Hiragino Mincho ProN", serif;
  --sans: "Zen Kaku Gothic New", "Noto Sans JP", "Hiragino Kaku Gothic ProN", sans-serif;
  --mono: "JetBrains Mono", "SFMono-Regular", Consolas, monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

body {
  background-image:
    linear-gradient(var(--paper) 0%, var(--paper) 100%),
    repeating-linear-gradient(transparent 0, transparent 34px, var(--paper-line) 35px);
  background-attachment: local;
}

a { color: inherit; }

.wrap {
  max-width: 880px;
  margin: 0 auto;
  padding: 32px 20px 120px;
}

/* ---------- ヘッダー ---------- */
.site-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  border-bottom: 3px double var(--ink);
  padding-bottom: 14px;
  margin-bottom: 28px;
}

.site-header .eyebrow {
  display: block;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--ink-soft);
  text-transform: uppercase;
  margin-bottom: 6px;
}

.site-header h1 {
  font-family: var(--serif);
  font-size: 1.6rem;
  font-weight: 700;
  margin: 0;
  letter-spacing: 0.02em;
}

.site-header .set-title {
  font-family: var(--serif);
  font-size: 1.15rem;
}

.home-link {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}
.home-link:hover { border-bottom-color: var(--accent); }

/* ---------- インデックスページ ---------- */
.set-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 14px;
  margin-top: 20px;
}

.set-card {
  display: block;
  background: var(--card-bg);
  border: 1px solid var(--paper-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px 18px;
  text-decoration: none;
  color: var(--ink);
  position: relative;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.set-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(43,42,37,0.08), 0 10px 26px rgba(43,42,37,0.1);
}
.set-card .set-id {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--accent);
  letter-spacing: 0.06em;
}
.set-card .set-name {
  font-family: var(--serif);
  font-size: 1.05rem;
  margin: 6px 0 10px;
}
.set-card .set-meta {
  font-size: 0.8rem;
  color: var(--ink-soft);
  display: flex;
  justify-content: space-between;
}
.set-card .progress-bar {
  height: 4px;
  border-radius: 2px;
  background: var(--paper-line);
  margin-top: 10px;
  overflow: hidden;
}
.set-card .progress-bar > span {
  display: block;
  height: 100%;
  background: var(--accent);
}

.empty-state {
  border: 1px dashed var(--paper-line);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
  color: var(--ink-soft);
  margin-top: 20px;
}
.empty-state code {
  background: var(--accent-soft);
  padding: 1px 6px;
  border-radius: 4px;
}

/* ---------- クイズ操作バー ---------- */
.toolbar {
  position: sticky;
  top: 0;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: wrap;
  background: rgba(250, 247, 240, 0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--paper-line);
  padding: 10px 0;
  margin: -10px 0 22px;
}

.toolbar .nav-links {
  display: flex;
  gap: 6px;
  align-items: center;
  font-family: var(--mono);
  font-size: 0.78rem;
}
.toolbar select {
  font-family: var(--mono);
  font-size: 0.78rem;
  padding: 5px 8px;
  border: 1px solid var(--paper-line);
  border-radius: 6px;
  background: var(--card-bg);
  color: var(--ink);
}

.btn {
  font-family: var(--sans);
  font-size: 0.82rem;
  font-weight: 600;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: var(--paper);
  padding: 7px 14px;
  border-radius: 999px;
  cursor: pointer;
  letter-spacing: 0.02em;
  transition: opacity 0.15s ease;
}
.btn:hover { opacity: 0.82; }
.btn.btn-outline {
  background: transparent;
  color: var(--ink);
}
.btn.btn-small { padding: 5px 12px; font-size: 0.76rem; }
.btn:disabled { opacity: 0.35; cursor: not-allowed; }

.progress-summary {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--ink-soft);
}

/* ---------- 問題カード ---------- */
.question {
  background: var(--card-bg);
  border: 1px solid var(--paper-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 22px 24px 20px;
  margin-bottom: 22px;
  position: relative;
}

.question-head {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 10px;
}

.question-num {
  font-family: var(--serif);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--accent);
  flex-shrink: 0;
  white-space: nowrap;
}

.question-type-badge {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--ink-soft);
  border: 1px solid var(--paper-line);
  border-radius: 999px;
  padding: 1px 8px;
  align-self: center;
  flex-shrink: 0;
}

.question-text {
  white-space: pre-line;
  margin: 0 0 16px;
  font-size: 0.98rem;
}

.choices { list-style: none; margin: 0; padding: 0; }

.choice {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 9px 10px;
  border-radius: 8px;
  margin-bottom: 4px;
  cursor: pointer;
  border: 1px solid transparent;
}
.choice:hover { background: var(--accent-soft); }

.choice input {
  margin-top: 3px;
  accent-color: var(--accent);
  flex-shrink: 0;
  cursor: pointer;
}

.choice-letter {
  font-family: var(--mono);
  font-weight: 700;
  color: var(--ink-soft);
  flex-shrink: 0;
}

.choice-text { flex: 1; }

.answer-mark {
  font-family: var(--serif);
  font-weight: 700;
  font-size: 0.72rem;
  color: var(--stamp);
  border: 1.5px solid var(--stamp);
  border-radius: 4px;
  padding: 0px 6px;
  transform: rotate(-6deg);
  margin-left: 6px;
  white-space: nowrap;
  flex-shrink: 0;
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.12s ease;
}

.question.revealed .answer-mark.is-correct {
  visibility: visible;
  opacity: 1;
}

.question.revealed .choice.is-correct {
  background: var(--accent-soft);
  border-color: var(--accent);
}
.question.revealed .choice.is-selected-wrong {
  background: var(--wrong-soft);
  border-color: var(--wrong);
}

.question-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px dashed var(--paper-line);
}

.question-result {
  font-family: var(--mono);
  font-size: 0.76rem;
  color: var(--ink-soft);
}
.question.revealed .question-result.is-correct-result { color: var(--accent); font-weight: 700; }
.question.revealed .question-result.is-wrong-result { color: var(--wrong); font-weight: 700; }

/* ---------- ページ送り ---------- */
.pager {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 28px;
  gap: 10px;
}
.pager .set-pill {
  font-family: var(--mono);
  font-size: 0.76rem;
  color: var(--ink-soft);
}

/* ---------- フッター ---------- */
.site-footer {
  text-align: center;
  color: var(--ink-soft);
  font-size: 0.76rem;
  margin-top: 40px;
  font-family: var(--mono);
}

/* ---------- レスポンシブ ---------- */
@media (max-width: 560px) {
  .wrap { padding: 20px 14px 100px; }
  .site-header h1 { font-size: 1.25rem; }
  .question { padding: 16px 16px 14px; }
  .toolbar { flex-direction: column; align-items: stretch; }
  .toolbar .nav-links { justify-content: space-between; }
}

/* ---------- キーボードフォーカス ---------- */
a:focus-visible, button:focus-visible, select:focus-visible, input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}