.book-detail-page{background:var(--paper)}
.book-detail-nav{height:82px;background:var(--navy);color:#fff;border-bottom:1px solid rgba(255,255,255,.08)}
.book-detail-nav-inner{height:100%;display:flex;align-items:center;justify-content:space-between;gap:20px}
.book-detail-nav .brand{width:190px;height:70px}.book-detail-nav .brand img{width:185px;height:70px;object-fit:contain}
.book-nav-actions{display:flex;align-items:center;gap:9px}
.nav-back,.library-nav-link,.track-nav-link{display:inline-flex;align-items:center;gap:7px;padding:10px 12px;border:1px solid rgba(255,255,255,.16);border-radius:5px;font-size:9px;font-weight:800}
.nav-back:hover,.library-nav-link:hover,.track-nav-link:hover{border-color:var(--orange)}
.nav-back svg,.library-nav-link svg,.track-nav-link svg{width:14px}
.book-detail-hero{padding:76px 0 82px;background:linear-gradient(180deg,#fff 0%,var(--paper) 100%)}
.book-detail-grid{display:grid;grid-template-columns:minmax(320px,500px) minmax(0,1fr);gap:82px;align-items:center}
.book-detail-cover{position:relative;min-height:570px;background:#e9e9ed;display:flex;align-items:center;justify-content:center;padding:45px}
.book-detail-cover:after{content:"";position:absolute;inset:0;background:linear-gradient(135deg,rgba(255,255,255,.28),transparent 40%,rgba(0,0,0,.04));pointer-events:none}
.book-detail-cover img{width:100%;height:480px;object-fit:contain;filter:drop-shadow(22px 28px 22px rgba(0,0,0,.22))}
.detail-badge{position:absolute;left:18px;top:18px;z-index:2;background:var(--navy);color:#fff;padding:8px 10px;font-size:8px;font-weight:800;letter-spacing:.13em;display:flex;gap:6px;align-items:center}.detail-badge svg{width:11px;color:var(--orange)}
.book-detail-copy{max-width:680px}.book-detail-copy h1{font:700 clamp(44px,5vw,74px)/1.03 var(--serif);letter-spacing:-.045em;color:var(--ink);margin:14px 0 18px}.book-detail-subtitle{font-size:13px;line-height:1.9;color:var(--muted);max-width:610px}
.book-price-row{display:flex;align-items:baseline;gap:8px;margin:30px 0 22px;flex-wrap:wrap}.book-price-row strong{font:700 34px var(--serif);color:var(--navy)}.book-price-row>span:not(.price-note){font-size:9px;font-weight:800;letter-spacing:.12em}.price-note{font-size:9px;color:#8b8b94;margin-left:10px}
.detail-divider{height:1px;background:var(--line);margin-bottom:24px}.book-detail-copy h2{font:700 23px var(--serif);margin-bottom:15px}.detail-features{display:grid;gap:11px;margin-bottom:28px}.detail-features li{display:flex;gap:10px;align-items:flex-start;font-size:10px;color:#55545d;list-style:none;line-height:1.6}.detail-features svg{width:15px;color:var(--orange);flex:none;margin-top:1px}
.detail-actions{display:flex;gap:10px;flex-wrap:wrap}.detail-actions .primary-btn{min-height:46px;padding:0 19px}.detail-cart-btn{min-height:46px;padding:0 17px;border:1px solid #cfcfd7;background:#fff;color:var(--navy);border-radius:5px;font-size:10px;font-weight:800;display:inline-flex;align-items:center;gap:8px}.detail-cart-btn svg{width:16px}.detail-cart-btn:hover{border-color:var(--orange);color:var(--orange)}
.detail-note{margin-top:19px;color:#7d7d86;font-size:9px;display:flex;gap:8px;align-items:flex-start;line-height:1.6}.detail-note svg{width:14px;color:var(--orange);flex:none}
.book-confidence{background:var(--navy);color:#fff}.confidence-grid{display:grid;grid-template-columns:repeat(3,1fr)}.confidence-grid>div{display:flex;gap:13px;padding:25px 24px;border-right:1px solid rgba(255,255,255,.12)}.confidence-grid>div:last-child{border-right:0}.confidence-grid>div>svg{width:21px;color:var(--orange);flex:none}.confidence-grid strong{display:block;font-size:11px}.confidence-grid span{display:block;color:#aaa8b4;font-size:9px;margin-top:3px}
.book-next-head{display:flex;justify-content:space-between;align-items:flex-end;gap:20px;margin-bottom:35px}.book-next-head h2{font:700 clamp(38px,4.5vw,58px) var(--serif);margin-top:10px}.book-next-head h2 span{color:var(--orange)}.dark-link{color:var(--navy);border-color:var(--navy)}
.related-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}.related-card{position:relative;background:#fff;border:1px solid var(--line);display:grid;grid-template-columns:120px 1fr auto;align-items:center;gap:20px;padding:18px;min-height:175px;box-shadow:0 10px 28px rgba(16,16,20,.04)}.related-card img{width:120px;height:140px;object-fit:contain;background:#ececf0}.related-card small{font-size:7px;font-weight:800;letter-spacing:.15em;color:#8a8a93}.related-card h3{font:700 21px/1.2 var(--serif);margin:8px 0}.related-card strong{font-size:11px;color:var(--navy)}.related-card>svg{width:18px;color:var(--orange)}
@media(max-width:1000px){.book-detail-grid{grid-template-columns:40% 1fr;gap:40px}.book-detail-cover{min-height:500px;padding:30px}.book-detail-cover img{height:420px}.book-detail-copy h1{font-size:52px}.confidence-grid>div{padding:22px 16px}}
@media(max-width:760px){.book-detail-nav{height:74px}.book-detail-nav .brand{width:155px;height:60px}.book-detail-nav .brand img{width:150px;height:60px}.book-nav-actions{gap:6px}.nav-back span,.library-nav-link span,.track-nav-link span{display:none}.nav-back,.library-nav-link,.track-nav-link{width:39px;height:39px;justify-content:center;padding:0}.book-detail-hero{padding:38px 0 55px}.book-detail-grid{display:block}.book-detail-cover{min-height:0;height:min(115vw,480px);padding:25px;margin-bottom:35px}.book-detail-cover img{height:100%;max-height:420px}.book-detail-copy h1{font-size:43px}.book-detail-subtitle{font-size:11px}.book-price-row{margin:22px 0 18px}.detail-actions{display:grid;grid-template-columns:1fr}.detail-actions .primary-btn,.detail-cart-btn{width:100%;justify-content:center}.confidence-grid{grid-template-columns:1fr}.confidence-grid>div{border-right:0;border-bottom:1px solid rgba(255,255,255,.12);padding:18px 0}.confidence-grid>div:last-child{border-bottom:0}.book-next-head{display:block}.book-next-head .secondary-link{margin-top:15px;display:inline-flex}.related-grid{grid-template-columns:1fr}.related-card{grid-template-columns:88px 1fr auto;gap:13px;padding:12px;min-height:140px}.related-card img{width:88px;height:112px}.related-card h3{font-size:17px}.related-card>svg{width:15px}}
@media(max-width:390px){.book-detail-copy h1{font-size:38px}.book-detail-cover{height:105vw}.related-card{grid-template-columns:74px 1fr auto}.related-card img{width:74px;height:98px}}

/* Final responsive hardening */
@media(max-width:430px){.book-detail-nav{padding-inline:9px}.book-detail-nav .brand{width:150px!important}.book-detail-nav .brand img{width:146px!important}.book-detail-copy h1{font-size:36px}.book-detail-cover{padding:18px;height:104vw}.book-detail-cover img{max-height:100%}.detail-actions{width:100%}.detail-actions>*{min-width:0}.related-card{grid-template-columns:68px minmax(0,1fr) auto}.related-card img{width:68px;height:92px}.related-card h3{font-size:16px}}