:root{--bg: #f8fafc;--surface: #ffffff;--text: #1e293b;--muted: #64748b;--border: #e2e8f0;--primary: #2563eb;--primary-dark: #1d4ed8;--accent: #f1f5f9;--radius: 10px;--maxw: 880px;--font: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", Meiryo, sans-serif}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:var(--font);color:var(--text);background:var(--bg);line-height:1.75;font-size:16px;-webkit-font-smoothing:antialiased}a{color:var(--primary);text-decoration:none}a:hover{text-decoration:underline}.container{max-width:var(--maxw);margin:0 auto;padding:0 16px}.site-header{background:var(--surface);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:10}.site-header .inner{max-width:var(--maxw);margin:0 auto;padding:12px 16px;display:flex;align-items:center;justify-content:space-between;gap:16px}.site-header .logo{font-weight:700;font-size:1.1rem;color:var(--text)}.site-header nav{display:flex;gap:16px;font-size:.9rem;flex-wrap:wrap;align-items:center}.site-header nav a.nav-top{background:var(--primary);color:#fff;padding:4px 12px;border-radius:999px;font-weight:700}.site-header nav a.nav-top:hover{background:var(--primary-dark);text-decoration:none}.site-header nav a.nav-yosou{background:#dc2626;color:#fff;padding:4px 12px;border-radius:999px;font-weight:700}.site-header nav a.nav-yosou:hover{background:#b91c1c;text-decoration:none}.site-footer{border-top:1px solid var(--border);margin-top:48px;padding:32px 16px;color:var(--muted);font-size:.85rem;background:var(--surface)}.site-footer .inner{max-width:var(--maxw);margin:0 auto}.site-footer nav{display:flex;gap:16px;margin-bottom:12px;flex-wrap:wrap}main{padding:24px 0 16px;min-height:60vh}h1{font-size:1.6rem;line-height:1.4}h2{font-size:1.3rem;border-left:4px solid var(--primary);padding-left:10px}.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:16px}.card{display:block;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:16px;color:inherit;transition:box-shadow .15s,transform .15s}.card:hover{text-decoration:none;box-shadow:0 4px 16px #0000000f;transform:translateY(-2px)}.tag{display:inline-block;font-size:.78rem;padding:2px 8px;border-radius:999px;background:var(--accent);color:var(--muted);margin:2px 4px 2px 0}.badge{display:inline-block;font-size:.75rem;font-weight:700;padding:2px 8px;border-radius:4px;color:#fff}.breadcrumb{font-size:.82rem;color:var(--muted);margin-bottom:16px}.breadcrumb a{color:var(--muted)}.question-meta{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-bottom:12px}.qtitle{font-weight:700;font-size:1.02rem;line-height:1.4;margin-bottom:6px}.choices{list-style:none;padding:0;margin:16px 0}.choices li{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:12px 16px;margin-bottom:8px}.choices .mark{font-weight:700;color:var(--primary);margin-right:8px}.reveal{margin:24px 0}.reveal>summary{cursor:pointer;background:var(--primary);color:#fff;padding:12px 16px;border-radius:var(--radius);font-weight:700;list-style:none;text-align:center;user-select:none}.reveal>summary::-webkit-details-marker{display:none}.reveal[open]>summary{border-radius:var(--radius) var(--radius) 0 0}.reveal .body{background:var(--surface);border:1px solid var(--border);border-top:none;border-radius:0 0 var(--radius) var(--radius);padding:8px 20px 20px}.ad-slot{margin:24px 0;padding:12px;background:var(--accent);border:1px dashed var(--border);border-radius:var(--radius);text-align:center;color:var(--muted);font-size:.8rem}.qfigure{margin:16px 0;text-align:center}.qfigure img{max-width:100%;height:auto;border:1px solid var(--border);border-radius:var(--radius);background:#fff}.subq{border-left:3px solid var(--border);padding-left:14px;margin:20px 0}.answer-main{font-size:1.1rem;background:#ecfdf5;border:1px solid #a7f3d0;border-radius:var(--radius);padding:10px 14px}.muted{color:var(--muted)}.note{background:#fffbeb;border:1px solid #fde68a;border-radius:var(--radius);padding:12px 16px;font-size:.9rem}