/* 世界史資料集 — 紙の資料集トーン（段取り帖と同系のミュート紙色） */
html, body { margin: 0; min-height: 100%; }

.sk-root {
  --paper: #DCDFD8; --card: #EBEDE6; --ink: #2E332C; --soft: #6C7268; --line: #C4C9BC;
  --eu: #5F7E97; --wa: #A97B61; --sa: #977089; --ea: #78906B; --am: #9F8A50;
  min-height: 100vh; background: var(--paper); color: var(--ink);
  font-family: "Hiragino Kaku Gothic ProN", "Yu Gothic Medium", Meiryo, system-ui, sans-serif;
  -webkit-font-smoothing: antialiased; letter-spacing: .01em;
}
.sk-root, .sk-root * { box-sizing: border-box; }

.sk-wrap { max-width: 860px; margin: 0 auto; padding: 22px 18px 80px; }
.sk-home { display: inline-block; margin-bottom: 10px; font-size: 11px; letter-spacing: .08em; color: var(--soft); text-decoration: none; }
.sk-home:hover { color: var(--ink); }
.sk-h1 { font-size: 20px; font-weight: 700; letter-spacing: .14em; margin: 0; }
.sk-sub { font-size: 12px; color: var(--soft); margin: 4px 0 0; letter-spacing: .06em; }
.sk-sub a { color: var(--soft); }

.sk-nav { display: flex; gap: 8px; margin: 16px 0; flex-wrap: wrap; }
.sk-navbtn {
  font-size: 12px; font-weight: 700; letter-spacing: .06em; padding: 7px 14px;
  border: 1px solid var(--line); border-radius: 999px; background: var(--card);
  color: var(--ink); text-decoration: none; cursor: pointer; font-family: inherit;
}
.sk-navbtn.on, .sk-navbtn:hover { border-color: var(--ink); }

/* 共時グリッド（縦=時代 / 横=地域） */
.sk-gridwrap { overflow-x: auto; margin-top: 8px; }
.sk-grid { border-collapse: collapse; width: 100%; min-width: 680px; }
.sk-grid th, .sk-grid td { border: 1px solid var(--line); padding: 6px 8px; vertical-align: top; }
.sk-grid thead th { font-size: 11px; letter-spacing: .08em; background: var(--card); position: sticky; top: 0; }
.sk-era-head { width: 120px; background: var(--card); }
.sk-era-name { font-size: 12.5px; font-weight: 700; display: block; color: var(--ink); text-decoration: none; }
.sk-era-name:hover { text-decoration: underline; text-underline-offset: 3px; }
.sk-era-span { font-size: 10px; color: var(--soft); letter-spacing: .04em; }
.sk-cell { min-width: 104px; }
.sk-chip {
  display: inline-block; margin: 1px 2px 1px 0; padding: 2px 7px; font-size: 11px; line-height: 1.5;
  border-radius: 9px; background: var(--card); border: 1px solid var(--line);
  color: var(--ink); text-decoration: none;
}
.sk-chip:hover { border-color: var(--ink); }
.sk-chip.done { opacity: .45; }
.sk-more { font-size: 10.5px; color: var(--soft); }

/* 理解度バロメータ */
.sk-baro { display: inline-flex; gap: 2px; margin-left: 5px; vertical-align: middle; }
.sk-dot { width: 5px; height: 5px; border-radius: 99px; background: var(--line); display: inline-block; }
.sk-dot.on { background: var(--ink); }

/* 時代ページ */
.sk-note { font-size: 13px; line-height: 1.8; margin: 10px 0 4px; }
.sk-extlink { font-size: 11.5px; color: var(--soft); }
.sk-map { width: 100%; height: auto; margin: 14px 0 6px; background: var(--card); border: 1px solid var(--line); border-radius: 12px; }
.sk-cols { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 14px; margin-top: 14px; }
.sk-col-head { font-size: 11px; font-weight: 700; letter-spacing: .1em; margin-bottom: 6px; }
.sk-term { display: block; padding: 9px 11px; margin-bottom: 7px; background: var(--card); border: 1px solid var(--line); border-radius: 10px; color: var(--ink); text-decoration: none; }
.sk-term:hover { border-color: var(--ink); }
.sk-term-name { font-size: 13px; font-weight: 600; }
.sk-term-desc { display: block; font-size: 11.5px; color: var(--soft); line-height: 1.6; margin-top: 2px; }
.sk-fig { display: inline-block; margin-left: 6px; font-size: 9.5px; letter-spacing: .08em; color: var(--soft); border: 1px solid var(--line); border-radius: 5px; padding: 0 4px; vertical-align: 1px; }
.sk-eranav { display: flex; justify-content: space-between; margin-top: 20px; padding-top: 12px; border-top: 1px solid var(--line); font-size: 12.5px; }
.sk-eranav a { color: var(--ink); text-decoration: none; }
.sk-eranav a:hover { text-decoration: underline; }

/* クイズ */
.sk-form { display: flex; flex-direction: column; gap: 12px; margin-top: 16px; max-width: 480px; }
.sk-field { display: flex; align-items: center; gap: 10px; font-size: 13px; }
.sk-field label { width: 92px; flex: 0 0 auto; color: var(--soft); font-size: 12px; letter-spacing: .06em; }
.sk-field select { flex: 1; font: inherit; font-size: 13px; padding: 7px 9px; border: 1px solid var(--line); border-radius: 9px; background: var(--card); color: var(--ink); }
.sk-check { display: flex; align-items: center; gap: 8px; font-size: 12.5px; }
.sk-start { align-self: flex-start; font-size: 13.5px; font-weight: 700; padding: 10px 22px; border: 1px solid var(--ink); border-radius: 999px; background: var(--ink); color: var(--paper); cursor: pointer; font-family: inherit; }
.sk-count-note { font-size: 11.5px; color: var(--soft); }

.sk-card { margin-top: 18px; background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 22px 18px; }
.sk-progress { font-size: 11px; color: var(--soft); letter-spacing: .08em; margin-bottom: 10px; }
.sk-front { font-size: 16px; font-weight: 600; line-height: 1.8; }
.sk-back { margin-top: 14px; padding-top: 14px; border-top: 1px dashed var(--line); }
.sk-answer { font-size: 17px; font-weight: 700; }
.sk-meta { font-size: 11.5px; color: var(--soft); margin-top: 5px; }
.sk-meta a { color: var(--soft); }
.sk-reveal { margin-top: 16px; font-size: 13px; font-weight: 700; padding: 9px 18px; border: 1px solid var(--ink); border-radius: 999px; background: none; color: var(--ink); cursor: pointer; font-family: inherit; }
.sk-grades { display: flex; gap: 7px; margin-top: 16px; flex-wrap: wrap; }
.sk-grade { flex: 1; min-width: 72px; font-size: 12px; font-weight: 700; padding: 9px 4px; border: 1px solid var(--line); border-radius: 10px; background: var(--paper); color: var(--ink); cursor: pointer; font-family: inherit; }
.sk-grade:hover { border-color: var(--ink); }
.sk-grade[data-v="3"] { background: var(--card); }
.sk-summary { margin-top: 18px; font-size: 13px; line-height: 2; }
.sk-status { font-size: 11px; color: var(--soft); letter-spacing: .06em; margin-left: 8px; }

/* テーマ史（貫通軸の年表） */
.sk-kind-head { margin-top: 18px; }
.sk-tl-row { display: flex; gap: 12px; margin-top: 12px; }
.sk-tl-era { flex: 0 0 108px; text-decoration: none; color: var(--ink); padding-top: 2px; }
.sk-tl-era-name { display: block; font-size: 12px; font-weight: 700; }
.sk-tl-era-span { display: block; font-size: 10px; color: var(--soft); }
.sk-tl-era:hover .sk-tl-era-name { text-decoration: underline; text-underline-offset: 3px; }
.sk-tl-body { flex: 1; border-left: 2px solid var(--line); padding: 0 0 6px 12px; }
.sk-tl-text { margin: 0 0 6px; font-size: 13px; line-height: 1.75; }

/* 入力モード（京大仕様: 書けるか） */
.sk-type-row { display: flex; gap: 8px; margin-top: 14px; }
.sk-type-input { flex: 1; min-width: 0; font: inherit; font-size: 15px; padding: 10px 12px;
  border: 1px solid var(--line); border-radius: 10px; background: var(--paper); color: var(--ink); }
.sk-type-input:focus { outline: none; border-color: var(--ink); }
.sk-judge { margin-top: 0; flex: 0 0 auto; }
.sk-verdict { font-size: 13px; font-weight: 800; letter-spacing: .12em; margin-bottom: 6px; }
.sk-verdict.ok { color: #5E6B4F; }
.sk-verdict.ng { color: #8A5A50; }
.sk-criteria { margin: 10px 0 4px; line-height: 1.7; }

/* 論述道場 */
.sk-essay-q { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 13px 14px; }
.sk-essay-input { width: 100%; font: inherit; font-size: 14px; line-height: 1.9; color: var(--ink);
  background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 12px 13px; margin-top: 12px; resize: vertical; }
.sk-essay-input:focus { outline: none; border-color: var(--ink); }
.sk-over { color: #8A5A50; font-weight: 700; }
.sk-checklist { margin-top: 12px; }
.sk-checklist .sk-check { margin: 6px 0; line-height: 1.6; align-items: flex-start; }
.sk-checklist .sk-check input { margin-top: 3px; }

/* 史料 */
.sk-shiryo-text { font-size: 14px; line-height: 2; background: var(--paper); border: 1px solid var(--line);
  border-radius: 10px; padding: 13px 14px; }

/* 今日の復習バナー: トップに置いて、忘れる前の一押しにする */
.sk-review { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap;
  margin: 4px 0 18px; padding: 14px 16px; text-decoration: none;
  background: var(--ink); color: var(--paper); border-radius: 12px; }
.sk-review:hover { opacity: .92; }
.sk-review-n { font-size: 16px; font-weight: 800; letter-spacing: .04em; }
.sk-review-sub { font-size: 11.5px; opacity: .78; letter-spacing: .04em; }
.sk-review.off { display: block; background: none; color: var(--soft);
  border: 1px dashed var(--line); font-size: 12px; padding: 11px 14px; }

/* 語彙層(tier2): 京大の角度・関連語・別解。骨格の下に敷く */
.sk-term-point { display: block; font-size: 11px; color: var(--ink); opacity: .72; line-height: 1.6; margin-top: 3px; }
.sk-term-point::before { content: "京大の角度 "; font-size: 9.5px; letter-spacing: .06em; color: var(--soft); opacity: .8; }
.sk-vocab-toggle { margin: 2px 0 12px; padding: 7px 12px; font: inherit; font-size: 11.5px; letter-spacing: .06em;
  color: var(--soft); background: none; border: 1px dashed var(--line); border-radius: 8px; cursor: pointer; width: 100%; }
.sk-vocab-toggle:hover { border-color: var(--soft); color: var(--ink); }
.sk-vocab-box { margin-top: 2px; }
/* クイズ裏面の学び直し */
.sk-backextra { margin: 10px 0 2px; }
.sk-point { font-size: 12.5px; line-height: 1.75; margin: 0 0 6px; }
.sk-point::before { content: "京大の角度 "; font-size: 10px; letter-spacing: .06em; color: var(--soft); }
.sk-alt { font-size: 11.5px; color: var(--soft); margin: 0 0 6px; }
.sk-rel { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }
.sk-rel-label { font-size: 10px; letter-spacing: .08em; color: var(--soft); }

/* 狭い画面: 共時グリッドは「時代カード」に切り替える（1時代の5地域が1画面に収まる） */
.sk-eracards { display: none; }
.sk-eracard { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 12px 13px; margin-bottom: 12px; }
.sk-eracard-head { display: flex; align-items: baseline; justify-content: space-between; gap: 8px; margin-bottom: 8px; }
.sk-eracard .sk-era-name { font-size: 14px; }
.sk-region-group { margin-top: 8px; }
.sk-region-label { font-size: 10px; font-weight: 700; letter-spacing: .1em; color: var(--soft); margin-bottom: 3px; }

/* 模式地図: 狭い画面ではラベルが潰れないよう最小幅を保って横スクロール */
.sk-mapwrap { overflow-x: auto; -webkit-overflow-scrolling: touch; margin: 14px 0 6px; }
.sk-mapwrap .sk-map { margin: 0; }

@media (max-width: 640px) {
  .sk-wrap { padding: 16px 13px 64px; }
  .sk-gridwrap { display: none; }        /* 表は畳んで */
  .sk-eracards { display: block; }        /* カードを出す */
  .sk-mapwrap .sk-map { min-width: 560px; }
  .sk-chip { padding: 5px 10px; font-size: 12px; }           /* タップしやすく */
  .sk-navbtn { padding: 9px 15px; }
  .sk-field { flex-direction: column; align-items: stretch; gap: 4px; }
  .sk-field label { width: auto; }
  .sk-reveal { width: 100%; padding: 13px 18px; }
  .sk-grade { min-width: 45%; padding: 13px 4px; font-size: 13px; }
  .sk-start { width: 100%; text-align: center; }
  .sk-term { padding: 11px 12px; }
}

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