:root{--primary: #2563eb;--primary-dark: #1d4ed8;--bg: #f8fafc;--surface: #ffffff;--text: #1e293b;--text-muted: #64748b;--border: #e2e8f0;--amazon-orange: #ff9900;--amazon-hover: #e68a00}*{margin:0;padding:0;box-sizing:border-box}body{font-family:Hiragino Kaku Gothic ProN,Noto Sans JP,system-ui,sans-serif;background:var(--bg);color:var(--text);line-height:1.6;min-width:320px}a{color:var(--primary);text-decoration:none}a:hover{text-decoration:underline}.container{max-width:960px;margin:0 auto;padding:0 16px}.header{background:var(--surface);border-bottom:1px solid var(--border);padding:12px 0;position:sticky;top:0;z-index:100}.header .container{display:flex;align-items:center;justify-content:space-between}.site-title{font-size:1.2rem;font-weight:700;color:var(--text)}.site-title:hover{text-decoration:none;color:var(--primary)}.nav{display:flex;gap:20px}.nav a{color:var(--text-muted);font-size:.9rem;font-weight:500}.nav a:hover{color:var(--primary);text-decoration:none}.main{padding:24px 16px 48px}h1{font-size:1.5rem;margin-bottom:8px}.subtitle{color:var(--text-muted);margin-bottom:24px;font-size:.9rem}.sort-tabs{display:flex;gap:8px;margin-bottom:24px}.sort-tab{padding:8px 16px;border:1px solid var(--border);background:var(--surface);border-radius:20px;cursor:pointer;font-size:.85rem;font-family:inherit;color:var(--text-muted);transition:all .2s}.sort-tab:hover{border-color:var(--primary);color:var(--primary)}.sort-tab.active{background:var(--primary);border-color:var(--primary);color:#fff}.ranking-list{display:flex;flex-direction:column;gap:8px}.ranking-card{display:flex;align-items:center;gap:16px;background:var(--surface);border:1px solid var(--border);border-radius:8px;padding:12px 16px;transition:box-shadow .2s}.ranking-card:hover{box-shadow:0 2px 8px #00000014}.rank{font-size:1.2rem;font-weight:700;color:var(--text-muted);min-width:36px;text-align:center}.ranking-card:nth-child(1) .rank{color:#fbbf24;font-size:1.4rem}.ranking-card:nth-child(2) .rank{color:#94a3b8;font-size:1.3rem}.ranking-card:nth-child(3) .rank{color:#d97706;font-size:1.3rem}.book-cover{width:60px;height:90px;object-fit:cover;border-radius:4px;flex-shrink:0;box-shadow:0 2px 4px #0000001a}.book-info{flex:1;min-width:0}.book-title{font-weight:600;font-size:.95rem;color:var(--text);display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.book-title:hover{color:var(--primary);text-decoration:none}.book-author{font-size:.8rem;color:var(--text-muted);display:block;margin-top:2px}.book-publisher{font-size:.75rem;color:var(--text-muted);display:block;margin-top:2px}.book-stats{display:flex;gap:12px;margin-top:4px;font-size:.75rem;color:var(--text-muted)}.amazon-btn{display:inline-block;padding:6px 14px;background:var(--amazon-orange);color:#fff;border-radius:4px;font-size:.8rem;font-weight:600;white-space:nowrap;transition:background .2s}.amazon-btn:hover{background:var(--amazon-hover);text-decoration:none}.more-link{text-align:center;margin-top:24px}.more-link a{font-weight:600}.back-link{display:inline-block;margin-bottom:16px;font-size:.9rem}.detail-header{display:flex;gap:20px;margin-bottom:24px}.detail-cover{width:140px;height:210px;object-fit:cover;border-radius:6px;flex-shrink:0;box-shadow:0 4px 8px #00000026}.detail-info{flex:1;min-width:0}.detail-title{font-size:1.6rem;margin-bottom:12px}.detail-meta{color:var(--text-muted);margin-bottom:20px;font-size:.9rem}.detail-meta p{margin-bottom:4px}.detail-stats{display:flex;gap:16px;margin-bottom:20px}.stat-card{background:var(--surface);border:1px solid var(--border);border-radius:8px;padding:16px 20px;text-align:center;flex:1}.stat-value{display:block;font-size:1.4rem;font-weight:700;color:var(--primary)}.stat-label{font-size:.75rem;color:var(--text-muted)}.amazon-btn-large{display:inline-block;padding:10px 24px;background:var(--amazon-orange);color:#fff;border-radius:6px;font-size:1rem;font-weight:600;margin-bottom:32px;transition:background .2s}.amazon-btn-large:hover{background:var(--amazon-hover);text-decoration:none}h2{font-size:1.2rem;margin-bottom:16px}.video-list{display:flex;flex-direction:column;gap:12px}.video-card{display:flex;gap:12px;background:var(--surface);border:1px solid var(--border);border-radius:8px;padding:12px}.video-thumb{width:160px;height:90px;object-fit:cover;border-radius:4px;flex-shrink:0}.video-info{flex:1;min-width:0}.video-title{font-weight:600;font-size:.9rem;display:block;margin-bottom:4px;color:var(--text)}.video-title:hover{color:var(--primary)}.video-channel{font-size:.8rem;color:var(--text-muted);display:block;margin-bottom:4px}.video-stats{display:flex;gap:12px;font-size:.75rem;color:var(--text-muted)}.footer{border-top:1px solid var(--border);padding:20px 0;text-align:center;color:var(--text-muted);font-size:.8rem}@media (max-width: 600px){.ranking-card{flex-wrap:wrap}.rank{min-width:28px}.book-cover{width:50px;height:75px}.book-stats{flex-wrap:wrap;gap:8px}.detail-header{flex-direction:column;align-items:center}.detail-cover{width:120px;height:180px}.detail-stats,.video-card{flex-direction:column}.video-thumb{width:100%;height:auto;aspect-ratio:16/9}}