* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; background: #faf9f6; color: #2a2a2a; line-height: 1.65; }
.wrap { max-width: 740px; margin: 0 auto; padding: 40px 20px 80px; }
.bc { font-size: .78rem; color: #aaa; margin-bottom: 28px; }
.bc a { color: #7a8c6e; text-decoration: none; }
.bc span { margin: 0 5px; }

.book-hero { display: grid; grid-template-columns: 140px 1fr; gap: 28px; align-items: start; margin-bottom: 40px; padding-bottom: 32px; border-bottom: 1px solid #e8e4dc; }
@media(max-width:500px) { .book-hero { grid-template-columns: 1fr; } }
.cover-slot { width: 140px; aspect-ratio: 2/3; background: #eceae3; border-radius: 6px; display: flex; align-items: center; justify-content: center; font-size: .72rem; color: #aaa; text-align: center; padding: 12px; border: 1px solid #ddd9cf; }
.cover-slot img { width: 100%; height: 100%; object-fit: cover; border-radius: 4px; }
.book-meta h1 { font-size: 1.6rem; font-weight: 800; line-height: 1.2; color: #1a1a1a; }
.book-meta .author { font-size: 1rem; color: #777; margin-top: 4px; }
.book-meta .pitch { margin-top: 14px; font-size: .97rem; color: #3a3a3a; line-height: 1.6; font-style: italic; border-left: 3px solid #7a8c6e; padding-left: 14px; }
.buy-btn { display: inline-block; margin-top: 16px; background: #7a8c6e; color: #fff; text-decoration: none; padding: 9px 18px; border-radius: 6px; font-size: .82rem; font-weight: 600; transition: background .15s; }
.buy-btn:hover { background: #5a6c4e; }
.buy-note { font-size: .72rem; color: #aaa; margin-top: 6px; }

.slabel { font-size: .68rem; font-weight: 800; text-transform: uppercase; letter-spacing: .14em; color: #7a8c6e; margin-bottom: 16px; margin-top: 44px; display: flex; align-items: center; gap: 8px; }
.slabel::after { content: ''; flex: 1; height: 1px; background: #e4e0d6; }

.concepts { display: flex; flex-direction: column; gap: 10px; }
.concept { background: #fff; border: 1.5px solid #e4e0d6; border-radius: 10px; overflow: hidden; cursor: pointer; transition: border-color .15s; }
.concept:hover, .concept.open { border-color: #7a8c6e; }
.concept-head { display: flex; justify-content: space-between; align-items: center; padding: 13px 16px; }
.concept-name { font-size: .9rem; font-weight: 700; color: #2a2a2a; }
.concept-tag { font-size: .72rem; background: #eceae3; border-radius: 12px; padding: 2px 9px; color: #666; white-space: nowrap; }
.concept-body { display: none; padding: 12px 16px 14px; font-size: .86rem; color: #555; line-height: 1.6; border-top: 1px solid #f0ede6; }
.concept.open .concept-body { display: block; }

.si-block { background: #f0ede6; border-radius: 10px; padding: 14px 18px; margin-bottom: 16px; }
.si-label { font-size: .72rem; font-weight: 700; text-transform: uppercase; letter-spacing: .08em; color: #7a8c6e; margin-bottom: 5px; }
.si-text { font-size: .88rem; color: #2a2a2a; line-height: 1.6; }

.hub-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.hub-chip { display: inline-block; border-radius: 20px; padding: 6px 14px; font-size: .8rem; font-weight: 600; text-decoration: none; transition: opacity .15s; }
.hub-chip.active { background: #7a8c6e; color: #fff; }
.hub-chip.active:hover { opacity: .8; }
.hub-chip.inactive { background: #eceae3; color: #bbb; cursor: default; }

.links { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-bottom: 0; }
@media(max-width:500px) { .links { grid-template-columns: 1fr; } }
.link-card { background: #fff; border: 1px solid #e4e0d6; border-radius: 8px; padding: 12px 14px; text-decoration: none; display: block; transition: border-color .15s; }
.link-card:hover { border-color: #7a8c6e; }
.link-card .ltext { font-size: .82rem; color: #3a3a3a; line-height: 1.45; }
.link-card .arrow { color: #7a8c6e; margin-right: 5px; }

.deep-block { background: #fff; border: 1.5px solid #e4e0d6; border-radius: 10px; padding: 18px 20px; display: flex; align-items: center; gap: 16px; text-decoration: none; transition: border-color .15s; }
.deep-block:hover { border-color: #7a8c6e; }
.deep-icon { font-size: 2rem; flex-shrink: 0; }
.deep-label { font-size: .7rem; font-weight: 700; text-transform: uppercase; letter-spacing: .08em; color: #7a8c6e; margin-bottom: 4px; }
.deep-title { font-size: .92rem; font-weight: 600; color: #2a2a2a; line-height: 1.4; }
.deep-desc { font-size: .8rem; color: #888; margin-top: 3px; }