.product-hero{display:grid;grid-template-columns:.82fr 1.18fr;gap:78px;align-items:center;padding-block:82px 88px;min-height:720px}
.product-cover-wrap{position:relative;display:grid;place-items:center;min-height:590px;isolation:isolate}.cover-glow{position:absolute;width:82%;aspect-ratio:1;border-radius:50%;background:radial-gradient(circle,rgba(103,199,255,.24),rgba(168,140,255,.11) 42%,transparent 70%);filter:blur(4px);z-index:-1}.product-cover{width:min(440px,88%);border-radius:22px;box-shadow:0 34px 85px rgba(0,0,0,.5);transform:rotate(-2.2deg);border:1px solid rgba(255,255,255,.14)}
.back-link{display:inline-flex;color:var(--muted);font-size:13px;margin-bottom:26px}.back-link:hover{color:white}.product-copy h1{font-size:clamp(54px,7vw,94px);line-height:.94;letter-spacing:-.055em;margin:0}.product-copy h1 span{color:#8ad8ff}.product-lead{font-size:19px;color:#c7cedc;max-width:650px;margin:28px 0}.fact-row{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;max-width:650px;margin:30px 0}.fact-row div{padding:17px 18px;border:1px solid var(--line);background:rgba(255,255,255,.035);border-radius:16px}.fact-row strong{display:block;font-size:18px}.fact-row span{display:block;color:var(--muted);font-size:10px;margin-top:4px;text-transform:uppercase;letter-spacing:.08em}.product-actions{display:flex;gap:12px;flex-wrap:wrap}.asin-line{font-size:11px;color:#7f899f;margin-top:12px;letter-spacing:.06em}
.product-section{border-top:1px solid var(--line)}.preview-section{padding-bottom:90px}.preview-heading{margin-bottom:18px}.gallery-controls{display:flex;align-items:center;justify-content:flex-end;gap:10px;margin-bottom:14px}.gallery-controls span{font-size:11px;color:var(--muted);text-transform:uppercase;letter-spacing:.12em}.gallery-arrow{width:38px;height:38px;border-radius:50%;border:1px solid var(--line);background:rgba(255,255,255,.04);color:white;font-size:18px;cursor:pointer}.gallery-arrow:hover{background:rgba(255,255,255,.09)}
.preview-rail{display:flex;gap:16px;overflow-x:auto;overscroll-behavior-inline:contain;scroll-snap-type:x mandatory;scrollbar-width:thin;padding:6px 2px 16px}.preview-card{scroll-snap-align:start;flex:0 0 clamp(230px,25vw,300px);border:1px solid var(--line);border-radius:20px;padding:10px;background:var(--panel);color:inherit;cursor:zoom-in;text-align:left;transition:.2s transform,.2s background}.preview-card:hover{transform:translateY(-4px);background:var(--panel2)}.preview-card img{width:100%;aspect-ratio:1;object-fit:cover;background:white;border-radius:13px}.preview-card span{display:block;padding:10px 4px 2px;color:var(--muted);font-size:11px;letter-spacing:.11em;text-transform:uppercase}
.about-book{display:grid;grid-template-columns:1.25fr .75fr;gap:60px;align-items:start}.about-copy h2{font-size:clamp(38px,4.6vw,60px)}.about-copy p:not(.eyebrow){font-size:17px;color:#c4cad7;max-width:760px}.detail-chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:26px}.detail-chips span{padding:8px 11px;border-radius:999px;border:1px solid var(--line);background:rgba(255,255,255,.035);font-size:11px;color:#d6dbe6}.book-note{border:1px solid var(--line);border-radius:26px;padding:30px;background:linear-gradient(145deg,#1b2540,#11182a)}.book-note strong{display:block;font-size:23px;line-height:1.25;margin:10px 0 12px}.book-note p{color:var(--muted);font-size:13px}.note-kicker{display:block;color:var(--gold);font-size:11px;font-weight:850;letter-spacing:.16em}.practical-note{position:sticky;top:105px}
.back-cover-section{border-top:1px solid var(--line)}.back-cover-card{display:grid;grid-template-columns:.88fr 1.12fr;gap:64px;align-items:center}.back-cover-image{position:relative;border:0;background:none;padding:0;cursor:zoom-in;border-radius:22px}.back-cover-image img{width:100%;border-radius:22px;box-shadow:0 28px 65px rgba(0,0,0,.35);border:1px solid rgba(255,255,255,.13)}.back-cover-image span{position:absolute;right:12px;bottom:12px;padding:7px 10px;border-radius:999px;background:rgba(8,12,22,.84);color:#e8edf6;font-size:10px;letter-spacing:.06em}.back-cover-copy h2{font-size:clamp(38px,4.6vw,60px);margin:0}.back-cover-copy p:not(.eyebrow){font-size:16px;color:#c4cad7;max-width:650px}.back-cover-copy .text-link{display:inline-flex;margin-top:8px}
.series-feature{display:grid;grid-template-columns:1fr 1fr;gap:58px;align-items:center;border-top:1px solid var(--line)}.series-feature-copy h2{font-size:clamp(38px,4.5vw,58px);margin:0}.series-feature-copy>p:not(.eyebrow){color:#c4cad7;max-width:650px}.series-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:27px}.series-cover-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;align-items:end}.series-cover-grid a{position:relative;border:1px solid var(--line);border-radius:16px;padding:7px;background:var(--panel);transition:.2s transform}.series-cover-grid a:hover{transform:translateY(-4px)}.series-cover-grid a.current{border-color:rgba(244,200,107,.62)}.series-cover-grid img{width:100%;aspect-ratio:1;object-fit:cover;border-radius:10px}.series-cover-grid span{display:block;padding:8px 3px 3px;font-size:11px;font-weight:750;text-align:center}
.buy-strip{margin-top:25px;border-top:1px solid var(--line);border-bottom:1px solid var(--line);background:radial-gradient(circle at 80% 50%,rgba(103,199,255,.11),transparent 30%),#101729}.buy-inner{min-height:250px;display:flex;align-items:center;justify-content:space-between;gap:40px}.buy-inner h2{font-size:clamp(35px,4vw,52px);margin:0}.buy-inner p:not(.eyebrow){color:var(--muted);margin-bottom:0;max-width:650px}
.image-lightbox{width:min(94vw,1120px);max-height:94vh;border:1px solid rgba(255,255,255,.18);border-radius:20px;padding:16px;background:#0a0f1d;box-shadow:0 35px 100px rgba(0,0,0,.7)}.image-lightbox::backdrop{background:rgba(0,0,0,.78);backdrop-filter:blur(6px)}.image-lightbox img{max-width:100%;max-height:calc(94vh - 32px);margin:auto;border-radius:12px;background:white}.lightbox-close{position:fixed;right:max(18px,calc((100vw - min(94vw,1120px))/2 + 18px));top:22px;z-index:3;width:42px;height:42px;border:1px solid rgba(255,255,255,.2);border-radius:50%;background:rgba(8,12,22,.88);color:white;font-size:27px;line-height:1;cursor:pointer}
@media (max-width:900px){.product-hero{grid-template-columns:1fr;gap:20px;padding-top:55px}.product-cover-wrap{min-height:460px}.product-copy{text-align:center}.back-link{justify-content:center}.product-lead{margin-inline:auto}.fact-row{margin-inline:auto}.product-actions{justify-content:center}.about-book,.back-cover-card,.series-feature{grid-template-columns:1fr}.practical-note{position:static}.back-cover-image{max-width:620px;margin-inline:auto}.series-cover-grid{max-width:720px;width:100%;margin-inline:auto}.series-feature-copy{text-align:center}.series-feature-copy>p:not(.eyebrow){margin-inline:auto}.series-actions{justify-content:center}}
@media (max-width:560px){.product-hero{padding-block:35px 54px}.product-cover-wrap{min-height:370px}.product-cover{width:min(335px,88%);border-radius:18px}.product-copy h1{font-size:52px}.product-lead{font-size:16px}.fact-row{grid-template-columns:1fr 1fr}.fact-row strong{font-size:15px}.product-actions .button{width:100%}.preview-section{padding-bottom:62px}.gallery-controls{justify-content:space-between}.preview-card{flex-basis:min(78vw,300px)}.about-book{gap:28px}.about-copy p:not(.eyebrow){font-size:15px}.book-note{padding:24px}.back-cover-card{gap:30px}.back-cover-copy p:not(.eyebrow){font-size:15px}.series-feature{gap:32px}.series-cover-grid{grid-template-columns:repeat(2,1fr);gap:9px}.series-actions .button{width:100%}.buy-inner{padding-block:40px;flex-direction:column;align-items:flex-start}.buy-inner .button{width:100%}.image-lightbox{padding:8px}.lightbox-close{right:14px;top:14px}}

/* v0.8 additions */
.breadcrumbs{display:flex;align-items:center;gap:9px;padding-top:22px;color:#7f899f;font-size:12px;letter-spacing:.02em}.breadcrumbs a{color:#9ba5b9}.breadcrumbs a:hover{color:white}.breadcrumbs span[aria-current="page"]{color:#cbd2df}
.cover-stage{display:grid;place-items:center;width:100%;min-height:520px}.product-cover{transition:opacity .18s ease,transform .18s ease}.product-cover.switching{opacity:.15;transform:rotate(-2.2deg) scale(.985)}.cover-switcher{display:inline-flex;gap:4px;padding:4px;margin-top:8px;border:1px solid var(--line);border-radius:999px;background:rgba(7,11,21,.72);backdrop-filter:blur(8px)}.cover-switcher button{border:0;border-radius:999px;padding:8px 15px;background:transparent;color:var(--muted);font:inherit;font-size:11px;font-weight:800;letter-spacing:.08em;text-transform:uppercase;cursor:pointer}.cover-switcher button.active{background:white;color:#0b1020}.cover-switcher button:hover:not(.active){color:white;background:rgba(255,255,255,.06)}
.preview-note{margin:10px 2px 0;color:#7f899f;font-size:11px}.preview-note strong{color:#aab4c7;font-weight:700}
.buy-actions{display:flex;gap:10px;flex-wrap:wrap;justify-content:flex-end}
.image-lightbox{position:relative;overflow:visible;padding:58px 72px 22px}.image-lightbox img{display:block;max-height:calc(94vh - 92px)}.lightbox-toolbar{position:absolute;left:18px;right:18px;top:12px;display:flex;align-items:center;justify-content:space-between;gap:16px}.lightbox-counter{color:#b7c0d1;font-size:11px;font-weight:800;letter-spacing:.12em;text-transform:uppercase}.lightbox-close{position:static;width:36px;height:36px;border:1px solid rgba(255,255,255,.2);border-radius:50%;background:rgba(255,255,255,.05);color:white;font-size:24px;line-height:1;cursor:pointer}.lightbox-nav{position:absolute;top:50%;transform:translateY(-50%);z-index:2;width:44px;height:44px;border:1px solid rgba(255,255,255,.2);border-radius:50%;background:rgba(8,12,22,.86);color:white;font-size:22px;cursor:pointer}.lightbox-prev{left:14px}.lightbox-next{right:14px}.lightbox-nav:hover,.lightbox-close:hover{background:rgba(255,255,255,.12)}
.mobile-amazon-sticky{display:none}
@media (max-width:900px){.breadcrumbs{padding-top:16px}.cover-stage{min-height:420px}.buy-actions{justify-content:flex-start}}
@media (max-width:560px){body{padding-bottom:72px}.breadcrumbs{padding-top:10px;font-size:11px;gap:7px;white-space:nowrap;overflow:hidden}.cover-stage{min-height:335px}.cover-switcher{margin-top:0}.image-lightbox{width:96vw;max-height:92vh;padding:50px 48px 14px;border-radius:16px}.image-lightbox img{max-height:calc(92vh - 70px)}.lightbox-toolbar{left:12px;right:12px;top:8px}.lightbox-nav{width:38px;height:38px;font-size:19px}.lightbox-prev{left:5px}.lightbox-next{right:5px}.buy-actions{width:100%}.buy-actions .button{width:100%}.mobile-amazon-sticky{position:fixed;left:10px;right:10px;bottom:10px;z-index:40;display:flex;align-items:center;justify-content:space-between;gap:12px;padding:11px 14px;border:1px solid rgba(255,255,255,.18);border-radius:15px;background:rgba(13,20,35,.94);box-shadow:0 12px 40px rgba(0,0,0,.46);backdrop-filter:blur(12px);color:white}.mobile-amazon-sticky span{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;color:#9ca7bc;font-size:10px}.mobile-amazon-sticky strong{flex:0 0 auto;font-size:12px;color:#8ad8ff}}

/* v0.9: previous / next book navigation */
.book-sibling-nav{display:grid;grid-template-columns:1fr 1fr;gap:14px;padding-block:36px 10px}.sibling-card{display:flex;flex-direction:column;gap:4px;padding:22px 24px;border:1px solid var(--line);border-radius:20px;background:linear-gradient(135deg,rgba(255,255,255,.045),rgba(255,255,255,.015));transition:.2s transform,.2s border-color}.sibling-card:hover{transform:translateY(-3px);border-color:rgba(244,200,107,.34)}.sibling-card.next{text-align:right;align-items:flex-end}.sibling-direction{color:var(--gold);font-size:10px;font-weight:850;letter-spacing:.13em;text-transform:uppercase}.sibling-card strong{font-size:20px}.sibling-card small{color:#8994a9;font-size:11px}
@media(max-width:560px){.book-sibling-nav{grid-template-columns:1fr;gap:10px}.sibling-card.next{text-align:left;align-items:flex-start}}

/* v1.0 — preserve mixed preview and cover proportions */
.preview-card{display:flex;flex-direction:column}
.preview-card img{width:100%;height:280px;aspect-ratio:auto;object-fit:contain;background:#fff;border-radius:13px}
.series-cover-grid img{width:100%;height:230px;aspect-ratio:auto;object-fit:contain;background:rgba(255,255,255,.025);border-radius:10px}
.series-cover-grid.count-2{grid-template-columns:repeat(2,minmax(0,1fr));max-width:500px;margin-inline:auto}
@media(max-width:560px){.preview-card img{height:250px}.series-cover-grid img{height:210px}}