:root{
  --bg:#f5f3ee;
  --paper:#fff;
  --ink:#15201d;
  --muted:#60706b;
  --line:#d9dfdc;
  --main:#1f3b36;
  --main-soft:#e5eeeb;
  --accent:#a45c2a;
  --ok:#176b4a;
  --ng:#9a3c33;
  --shadow:0 8px 24px rgba(22,35,31,.08);
  --radius:18px;
}
*{box-sizing:border-box}
html{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Hiragino Kaku Gothic ProN","Yu Gothic",Meiryo,sans-serif;background:var(--bg);color:var(--ink)}
body{margin:0;line-height:1.75}
button,input,select{font:inherit}
button{cursor:pointer}
a{color:var(--main)}
.site-header{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.94);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.header-inner{max-width:1120px;margin:auto;display:flex;align-items:center;justify-content:space-between;gap:16px;padding:12px 18px}
.brand{border:0;background:none;font-weight:800;color:var(--main);font-size:18px;padding:8px 0}
.top-nav{display:flex;gap:6px}
.top-nav button{border:0;background:transparent;padding:8px 10px;border-radius:10px;color:var(--ink)}
.top-nav button:hover,.top-nav button:focus-visible{background:var(--main-soft)}
.app-shell{max-width:1120px;margin:0 auto;padding:26px 18px 64px}
.site-footer{border-top:1px solid var(--line);text-align:center;color:var(--muted);padding:24px 18px;background:#fff}
.hero{display:grid;grid-template-columns:1.35fr .65fr;gap:20px;align-items:stretch;margin-bottom:24px}
.hero-main,.hero-stats,.panel,.mode-card,.person-card,.feedback-card,.source-card,.timeline-card{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}
.hero-main{padding:30px}
.eyebrow{font-size:13px;font-weight:800;color:var(--accent);letter-spacing:.08em;margin:0 0 6px}
h1,h2,h3{line-height:1.35;margin-top:0}
h1{font-size:clamp(28px,5vw,48px);margin-bottom:12px}
.lead{font-size:17px;color:#354641;max-width:760px;margin-bottom:0}
.hero-stats{display:grid;grid-template-columns:1fr 1fr;gap:1px;overflow:hidden;background:var(--line)}
.stat{background:#fff;padding:22px;text-align:center;display:flex;flex-direction:column;justify-content:center}
.stat strong{font-size:32px;color:var(--main);line-height:1.1}.stat span{font-size:13px;color:var(--muted);margin-top:8px}
.section-head{display:flex;justify-content:space-between;gap:14px;align-items:end;margin:28px 0 12px}
.section-head h2{margin:0}.section-head p{margin:0;color:var(--muted);font-size:14px}
.mode-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
.mode-card{padding:22px;display:flex;flex-direction:column;min-height:230px}
.mode-card .mode-no{display:inline-flex;width:34px;height:34px;align-items:center;justify-content:center;border-radius:50%;background:var(--main-soft);color:var(--main);font-weight:800;margin-bottom:14px}
.mode-card p{color:var(--muted);margin-top:0;flex:1}
.primary-btn,.secondary-btn,.ghost-btn{border-radius:12px;min-height:46px;padding:10px 16px;font-weight:800}
.primary-btn{border:1px solid var(--main);background:var(--main);color:#fff}.primary-btn:hover{filter:brightness(1.08)}
.secondary-btn{border:1px solid var(--main);background:#fff;color:var(--main)}
.ghost-btn{border:1px solid var(--line);background:#fff;color:var(--ink)}
.era-grid{display:flex;flex-wrap:wrap;gap:8px}
.era-chip{border:1px solid var(--line);background:#fff;border-radius:999px;padding:8px 13px}.era-chip.is-active{background:var(--main);color:#fff;border-color:var(--main)}
.panel{padding:22px;margin-top:18px}
.game-top{display:flex;justify-content:space-between;gap:12px;align-items:flex-start;margin-bottom:18px}.game-top h2{margin-bottom:4px}.game-top p{margin:0;color:var(--muted)}
.progress-pill{white-space:nowrap;background:var(--main-soft);color:var(--main);font-weight:800;border-radius:999px;padding:7px 12px;font-size:13px}
.match-layout{display:grid;grid-template-columns:1fr 1fr;gap:18px}.match-column h3{font-size:15px;color:var(--muted);margin-bottom:10px}
.select-card{width:100%;text-align:left;border:1px solid var(--line);background:#fff;border-radius:14px;padding:14px;margin-bottom:9px;color:var(--ink)}
.select-card strong{display:block;margin-bottom:3px}.select-card span{display:block;color:var(--muted);font-size:13px}.select-card.is-selected{border-color:var(--accent);box-shadow:0 0 0 2px rgba(164,92,42,.12)}.select-card.is-paired{background:var(--main-soft)}
.pairs{margin:16px 0 0;padding:0;list-style:none;display:grid;gap:8px}.pairs li{border:1px dashed var(--line);border-radius:12px;padding:10px 12px;background:#fafafa}.pairs button{float:right;border:0;background:none;color:var(--ng);font-weight:700}
.action-row{display:flex;gap:10px;flex-wrap:wrap;margin-top:18px}
.feedback-grid{display:grid;gap:12px;margin-top:18px}.feedback-card{padding:18px;box-shadow:none}.feedback-card.ok{border-left:5px solid var(--ok)}.feedback-card.ng{border-left:5px solid var(--ng)}.feedback-label{font-weight:800;margin:0 0 6px}.feedback-card p{margin:6px 0}.feedback-card .explain{color:#34433f;background:#f7f8f7;padding:12px;border-radius:10px}.feedback-card .sources-inline{font-size:12px;color:var(--muted);margin-top:10px}
.timeline-pool{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}.timeline-card{padding:14px;border:1px solid var(--line);box-shadow:none}.timeline-card button{width:100%;border:0;background:none;text-align:left;padding:0;color:inherit}.timeline-card strong{display:block}.timeline-card span{color:var(--muted);font-size:13px}.timeline-card.is-used{opacity:.38;pointer-events:none}
.timeline-answer{min-height:90px;border:2px dashed var(--line);border-radius:14px;padding:12px;margin-top:14px}.timeline-answer ol{margin:0;padding-left:24px}.timeline-answer li{margin:7px 0}
.people-tools{display:grid;grid-template-columns:1fr 220px;gap:10px;margin-bottom:14px}.people-tools input,.people-tools select{width:100%;border:1px solid var(--line);background:#fff;border-radius:12px;padding:12px 13px}
.people-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.person-card{padding:18px;box-shadow:none}.person-card h3{margin-bottom:4px}.person-meta{color:var(--muted);font-size:13px;margin:0 0 12px}.person-card p{margin:6px 0}.person-card .label{font-size:12px;font-weight:800;color:var(--accent)}
.source-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}.source-card{padding:18px;box-shadow:none}.source-card h3{font-size:17px;margin-bottom:6px}.source-card p{color:var(--muted);font-size:14px}.source-card a{font-weight:800}
.notice{background:#fff8e9;border:1px solid #ecd8ad;border-radius:14px;padding:14px 16px;margin:14px 0;color:#5f4b22}.small{font-size:13px;color:var(--muted)}
.empty{padding:30px;text-align:center;color:var(--muted)}
.loading-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:30px}
@media(max-width:820px){.hero{grid-template-columns:1fr}.mode-grid,.people-grid{grid-template-columns:1fr 1fr}.source-grid{grid-template-columns:1fr}.match-layout{grid-template-columns:1fr}.hero-stats{min-height:150px}}
@media(max-width:560px){.header-inner{padding:8px 12px}.brand{font-size:15px}.top-nav button{font-size:13px;padding:7px 6px}.app-shell{padding:18px 12px 48px}.hero-main,.panel{padding:18px}.mode-grid,.people-grid{grid-template-columns:1fr}.people-tools{grid-template-columns:1fr}.timeline-pool{grid-template-columns:1fr}.hero-stats{grid-template-columns:1fr 1fr}.game-top{display:block}.progress-pill{display:inline-block;margin-top:10px}.action-row{display:grid;grid-template-columns:1fr 1fr}.action-row .primary-btn{grid-column:1/-1}.section-head{display:block}.section-head p{margin-top:5px}}

/* 総合トップへ戻るリンク */
.top-nav .portal-link{display:inline-flex;align-items:center;justify-content:center;text-decoration:none;color:inherit;font:inherit;padding:.55rem .7rem;border-radius:.65rem;}
.top-nav .portal-link:hover{background:rgba(0,0,0,.06);}
@media (max-width:640px){.top-nav .portal-link{padding:.5rem .55rem;font-size:.88rem;}}

/* v1.1: smartphone compact layout */
@media (max-width:560px){
  body{line-height:1.5}
  .site-header{position:sticky;top:0;z-index:20}
  .header-inner{padding:5px 8px;gap:6px;overflow-x:auto;scrollbar-width:none}
  .header-inner::-webkit-scrollbar{display:none}
  .brand{font-size:14px;padding:4px 0;white-space:nowrap;flex:0 0 auto}
  .top-nav{gap:0;flex:0 0 auto;white-space:nowrap}
  .top-nav button,.top-nav .portal-link{font-size:12px;padding:5px 5px;border-radius:7px;white-space:nowrap}

  .app-shell{padding:10px 8px 24px}
  .hero{gap:8px;margin-bottom:10px}
  .hero-main,.panel{padding:12px}
  .hero-main h1{font-size:25px;line-height:1.2;margin-bottom:6px}
  .eyebrow{font-size:11px;margin-bottom:3px}
  .lead{font-size:14px;line-height:1.55}
  .hero-stats{min-height:0}
  .stat{padding:8px 6px}
  .stat strong{font-size:23px}
  .stat span{font-size:11px;margin-top:2px;line-height:1.3}

  .section-head{margin:14px 0 7px}
  .section-head h2{font-size:20px;line-height:1.25}
  .section-head p{font-size:12px;margin-top:2px;line-height:1.45}
  .mode-grid,.people-grid,.source-grid{gap:7px}
  .mode-card{padding:12px;min-height:0}
  .mode-card .mode-no{width:26px;height:26px;font-size:12px;margin-bottom:6px}
  .mode-card h3{font-size:17px;margin-bottom:5px}
  .mode-card p{font-size:13px;line-height:1.45;margin-bottom:8px}

  .primary-btn,.secondary-btn,.ghost-btn{min-height:40px;padding:7px 10px;border-radius:9px}
  .era-grid{gap:5px}
  .era-chip{padding:6px 9px;font-size:12px}
  .panel{margin-top:9px}
  .game-top{margin-bottom:9px}
  .game-top h2{font-size:20px;margin-bottom:2px}
  .game-top p{font-size:12px;line-height:1.4}
  .progress-pill{padding:5px 8px;font-size:11px;margin-top:5px}
  .match-layout{gap:8px}
  .match-column h3{font-size:13px;margin-bottom:5px}
  .select-card{border-radius:10px;padding:9px 10px;margin-bottom:5px;line-height:1.4}
  .select-card strong{margin-bottom:1px}
  .select-card span{font-size:12px;line-height:1.35}
  .pairs{margin-top:8px;gap:5px}
  .pairs li{padding:7px 9px;border-radius:9px;font-size:13px}
  .action-row{gap:6px;margin-top:9px}
  .feedback-grid{gap:7px;margin-top:9px}
  .feedback-card{padding:10px}
  .feedback-label{margin-bottom:3px}
  .feedback-card p{margin:3px 0;line-height:1.45}
  .feedback-card .explain{padding:8px;border-radius:7px}
  .feedback-card .sources-inline{margin-top:5px}

  .timeline-pool{gap:6px}
  .timeline-card{padding:9px}
  .timeline-card span{font-size:12px}
  .timeline-answer{min-height:0;padding:8px;margin-top:7px;border-radius:10px}
  .timeline-answer ol{padding-left:20px}
  .timeline-answer li{margin:3px 0;line-height:1.4}

  .people-tools{gap:6px;margin-bottom:7px}
  .people-tools input,.people-tools select{padding:9px 10px;border-radius:9px}
  .person-card,.source-card{padding:10px}
  .person-card h3,.source-card h3{margin-bottom:2px}
  .person-meta{font-size:11px;margin-bottom:5px}
  .person-card p,.source-card p{margin:3px 0;line-height:1.45}
  .person-card .label{font-size:11px;margin-right:.35em;white-space:nowrap}
  .source-card p{font-size:12px}
  .notice{padding:8px 10px;margin:7px 0;border-radius:9px;font-size:12px;line-height:1.45}
  .empty,.loading-card{padding:16px}
  .site-footer{padding:10px 8px;font-size:11px;line-height:1.4}
  .site-footer p{margin:0}
}


/* v1.2: game controls and single-target quiz layout */
.action-row{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:8px;
  margin-top:14px;
}
.action-row .primary-btn{
  grid-column:1 / -1;
  grid-row:1;
  min-height:46px;
  font-size:15px;
  padding:10px 16px;
}
.action-row [data-check],
.action-row [data-check-timeline],
.action-row [data-check-match],
.action-row [data-check-features],
.action-row [data-check-guess],
.action-row [data-check-chronology]{
  min-height:58px;
  font-size:16px;
  padding:12px 16px;
}
.action-row .secondary-btn,
.action-row .ghost-btn{
  grid-row:2;
  min-height:40px;
}
.choice-grid,.guess-grid{display:grid;grid-template-columns:1fr 1fr;gap:9px}
.choice-card,.guess-card{
  width:100%;
  border:1px solid var(--line);
  background:#fff;
  color:var(--ink);
  border-radius:12px;
  padding:12px;
  text-align:left;
}
.choice-card span,.guess-card span{display:block;color:var(--muted);font-size:12px;margin-bottom:3px}
.choice-card strong,.guess-card strong{display:block;line-height:1.45}
.choice-card.is-selected,.guess-card.is-selected{border-color:var(--accent);background:#fffaf4;box-shadow:0 0 0 2px rgba(164,92,42,.14)}
.choice-count{margin:8px 0 0;text-align:right;color:var(--muted);font-size:13px;font-weight:700}
.hint-list{display:grid;gap:8px;margin:8px 0 12px}
.hint-list>div{border:1px solid var(--line);background:#fbfcfb;border-radius:11px;padding:10px 12px}
.hint-list b{color:var(--main);font-size:13px}
.hint-list p{margin:2px 0 0;line-height:1.5}
.choice-review{display:grid;grid-template-columns:1fr 1fr;gap:7px;margin:10px 0}
.review-card{border:1px solid var(--line);border-radius:10px;padding:9px;background:#fff}
.review-card.ok{border-left:4px solid var(--ok)}
.review-card.ng{opacity:.72}
.review-card span{font-size:11px;color:var(--muted);font-weight:800}
.review-card p{margin:3px 0;line-height:1.45}
.review-card b{font-size:11px;color:var(--accent)}
@media(max-width:560px){
  .action-row{gap:5px;margin-top:8px}
  .action-row .primary-btn{min-height:42px;font-size:14px;padding:8px 10px}
  .action-row [data-check],
  .action-row [data-check-timeline],
  .action-row [data-check-match],
  .action-row [data-check-features],
  .action-row [data-check-guess],
.action-row [data-check-chronology]{min-height:56px;font-size:16px;padding:10px 12px}
  .action-row .secondary-btn,.action-row .ghost-btn{min-height:36px;padding:6px 8px;font-size:12px}
  .choice-grid,.guess-grid{grid-template-columns:1fr;gap:5px}
  .choice-card,.guess-card{padding:9px 10px;border-radius:9px}
  .choice-card span,.guess-card span{font-size:11px;margin-bottom:1px}
  .choice-card strong,.guess-card strong{font-size:13px;line-height:1.4}
  .choice-count{font-size:12px;margin-top:4px}
  .hint-list{gap:5px;margin:5px 0 8px}
  .hint-list>div{padding:7px 9px;border-radius:8px}
  .hint-list b{font-size:11px;display:inline;margin-right:.4em}
  .hint-list p{display:inline;font-size:12px;line-height:1.4}
  .choice-review{grid-template-columns:1fr;gap:4px;margin:6px 0}
  .review-card{padding:7px 8px}
  .review-card p{font-size:12px;margin:2px 0}
}

/* v1.3: mixed chronology mode */
.chronology-pool .timeline-card button{display:flex;flex-direction:column;gap:3px}
.chronology-type{display:inline-block;width:max-content;font-size:11px!important;font-weight:800;color:var(--accent)!important;background:#fff7ef;border:1px solid #ead4c2;border-radius:999px;padding:2px 7px}
.answer-type{display:inline-block;margin-left:5px;font-size:10px;font-weight:800;color:var(--muted);border:1px solid var(--line);border-radius:999px;padding:1px 6px;vertical-align:middle}
@media(max-width:820px){.mode-grid{grid-template-columns:1fr 1fr}}
@media(max-width:560px){.mode-grid{grid-template-columns:1fr}.chronology-type{font-size:10px!important;padding:1px 6px}.chronology-pool .timeline-card{padding:8px}}