.book-hero{padding:150px max(6vw,24px) 70px;display:grid;grid-template-columns:minmax(260px,.58fr) minmax(0,1.25fr);gap:clamp(36px,7vw,100px);align-items:center;background:linear-gradient(135deg,#f4f7f5 0%,#fff 55%,#eef4f0 100%)}
.book-cover-wrap{max-width:460px;margin:auto;padding:16px;background:#fff;border:1px solid #d9e3dd;box-shadow:0 28px 70px rgba(7,25,47,.18)}.book-cover-wrap img{display:block;width:100%;height:auto}.book-hero-copy h1{max-width:920px;margin:10px 0 18px;color:#07192f;font-size:clamp(40px,5vw,72px);line-height:.98;letter-spacing:-.035em}.book-subtitle{max-width:880px;font-size:clamp(20px,2vw,29px);line-height:1.35;color:#2f3b43;font-weight:700}.book-hero .lead{max-width:850px;font-size:18px;line-height:1.75;color:#52616b}.book-badges{display:flex;flex-wrap:wrap;gap:9px;margin:26px 0}.book-badges span,.department-cloud span,.audience-grid span{padding:9px 12px;border:1px solid #d9e3dd;border-radius:999px;background:#fff;color:#123b59;font-weight:800;font-size:13px}.purchase-panel{display:flex;align-items:center;justify-content:space-between;gap:20px;max-width:760px;margin-top:28px;padding:20px;border-radius:10px;background:#07192f;color:#fff}.purchase-panel small{display:block;color:#a9bbc7}.purchase-panel strong{display:block;margin-top:4px;font-size:24px}.purchase-panel .btn[disabled],.book-final-cta .btn[disabled]{opacity:.82;cursor:not-allowed}.microcopy{font-size:12px;color:#71808a}.book-trust{display:grid;grid-template-columns:repeat(5,1fr);background:#07192f;color:#fff;padding:22px max(6vw,24px);gap:1px}.book-trust div{padding:12px 18px;border-right:1px solid rgba(255,255,255,.14)}.book-trust strong,.book-trust span{display:block}.book-trust strong{font-size:20px}.book-trust span{margin-top:3px;color:#b9c8d2;font-size:12px}.book-intro,.feature-section,.drawing-section,.department-section,.calc-section,.audience-section,.book-faq,.disclaimer-section{padding-top:80px;padding-bottom:80px}.architecture-flow,.calc-flow{display:flex;flex-wrap:wrap;align-items:center;gap:10px;margin-top:30px}.architecture-flow span,.calc-flow span{padding:14px 16px;background:#fff;border:1px solid #d9e3dd;border-radius:7px;color:#123b59;font-weight:900}.architecture-flow b,.calc-flow b{color:#2e6b3a}.architecture-note{color:#52616b}.feature-section{background:#f3f6f4}.feature-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.feature-grid article{padding:24px;background:#fff;border:1px solid #d9e3dd;border-radius:8px;box-shadow:0 10px 30px rgba(7,25,47,.05)}.feature-grid h3{margin-top:0;color:#123b59}.feature-grid p{color:#52616b;line-height:1.65}.drawing-section{display:grid;grid-template-columns:1.2fr .8fr;gap:60px;align-items:center;background:#fff}.drawing-copy h2,.calc-section h2,.disclaimer-section h2{color:#123b59;font-size:clamp(32px,4vw,52px);line-height:1.05}.drawing-copy li{margin:10px 0}.drawing-card{padding:46px 34px;background:#07192f;color:#fff;border-radius:10px;box-shadow:0 25px 55px rgba(7,25,47,.18)}.drawing-card .drawing-number{color:#72d9a6;font-size:15px;font-weight:950;letter-spacing:.04em}.drawing-card strong{display:block;margin:14px 0 8px;font-size:30px}.drawing-card span{color:#bdcad3}.department-cloud,.audience-grid{display:flex;flex-wrap:wrap;gap:10px}.calc-section{display:grid;grid-template-columns:.75fr 1.25fr;gap:50px;align-items:center;background:#07192f;color:#fff}.calc-section h2{color:#fff}.calc-section .eyebrow{color:#72d9a6}.calc-flow span{background:rgba(255,255,255,.06);border-color:rgba(255,255,255,.18);color:#fff}.book-faq{background:#f3f6f4}.disclaimer-section{background:#fff}.disclaimer-section p{max-width:1050px;color:#52616b;line-height:1.75}.book-final-cta{display:flex;justify-content:space-between;align-items:center;gap:30px;padding:60px max(6vw,24px);background:linear-gradient(135deg,#123b59,#07192f);color:#fff}.book-final-cta h2{margin:8px 0;font-size:clamp(32px,4vw,52px);line-height:1.05}.book-final-cta .eyebrow{color:#72d9a6}.book-final-cta p{color:#c6d2da}
@media(max-width:900px){.book-hero,.drawing-section,.calc-section{grid-template-columns:1fr}.book-cover-wrap{max-width:360px}.book-trust{grid-template-columns:repeat(2,1fr)}.feature-grid{grid-template-columns:1fr 1fr}.purchase-panel,.book-final-cta{align-items:flex-start;flex-direction:column}.book-hero-copy h1{font-size:44px}}
@media(max-width:600px){.book-hero{padding-top:120px}.feature-grid{grid-template-columns:1fr}.book-trust{grid-template-columns:1fr}.book-trust div{border-right:0;border-bottom:1px solid rgba(255,255,255,.14)}.book-hero-copy h1{font-size:37px}.book-subtitle{font-size:19px}}
/* Book preview — first 50 pages only */
.book-preview-section{padding-top:80px;padding-bottom:80px;background:#eef3f0}.book-preview{max-width:1120px;margin:32px auto 0}.preview-toolbar{display:flex;align-items:center;justify-content:center;gap:14px;flex-wrap:wrap;margin-bottom:16px}.preview-toolbar button{border:0;border-radius:7px;background:#123b59;color:#fff;padding:11px 18px;font-weight:900;cursor:pointer}.preview-toolbar button:disabled{opacity:.35;cursor:not-allowed}.preview-page-number{min-width:110px;text-align:center;color:#123b59;font-weight:900}.preview-range{width:min(420px,70vw);accent-color:#2e6b3a}.preview-stage{display:flex;justify-content:center;align-items:flex-start;min-height:500px;padding:22px;background:#dfe7e2;border:1px solid #ccd8d1;border-radius:10px;box-shadow:inset 0 1px 8px rgba(7,25,47,.08)}.preview-stage img{display:block;max-width:100%;width:auto;max-height:82vh;background:#fff;box-shadow:0 12px 38px rgba(7,25,47,.2);user-select:none;-webkit-user-drag:none}.preview-note{text-align:center;color:#52616b;font-size:13px;margin-top:12px}.preview-purchase{max-width:820px;margin:28px auto 0;padding:28px;border-radius:10px;background:#07192f;color:#fff;text-align:center}.preview-purchase h3{margin:0 0 8px;font-size:28px}.preview-purchase p{color:#c6d2da}.preview-purchase .btn{display:inline-flex;align-items:center;justify-content:center;margin-top:8px}.preview-purchase .btn[aria-disabled="true"]{opacity:.75;cursor:not-allowed}.preview-limit{font-size:12px!important;color:#9fb0bc!important}.preview-noscript{padding:18px;background:#fff3cd;border:1px solid #ead78a;color:#4e4216;border-radius:7px}@media(max-width:600px){.book-preview-section{padding-top:55px;padding-bottom:55px}.preview-stage{padding:8px;min-height:300px}.preview-toolbar{gap:8px}.preview-toolbar button{padding:9px 13px}.preview-purchase{padding:22px 16px}}
.shop-actions{display:flex;gap:12px;flex-wrap:wrap;justify-content:flex-end}.shop-actions .buy-now{background:#2e6b3a}.preview-purchase .btn,.book-final-cta .btn,.shop-actions .btn{position:relative;z-index:5;pointer-events:auto;cursor:pointer}
/* Engineering library catalogue */
.shop-library-hero{padding:160px max(6vw,24px) 78px;background:linear-gradient(135deg,#07192f,#123b59);color:#fff}.shop-library-hero .eyebrow{color:#72d9a6}.shop-library-hero h1{max-width:980px;margin:10px 0 18px;font-size:clamp(44px,6vw,78px);line-height:.98;letter-spacing:-.04em}.shop-library-hero>p:last-child{max-width:850px;color:#c6d2da;font-size:19px;line-height:1.7}.shop-catalog{padding-top:75px;padding-bottom:90px;background:#f3f6f4}.shop-category-tabs{display:flex;gap:10px;flex-wrap:wrap;margin:26px 0 34px}.shop-category-tabs button{border:1px solid #cad8d0;background:#fff;color:#123b59;padding:11px 15px;border-radius:999px;font-weight:850;cursor:pointer}.shop-category-tabs button.active{background:#123b59;color:#fff;border-color:#123b59}.shop-product-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:28px}.shop-product-card{display:grid;grid-template-columns:minmax(180px,.58fr) 1.15fr;background:#fff;border:1px solid #d9e3dd;border-radius:12px;overflow:hidden;box-shadow:0 14px 38px rgba(7,25,47,.07)}.shop-cover-link{padding:22px;background:#e8efeb;display:flex;align-items:center;justify-content:center}.shop-cover-link img{display:block;width:100%;max-width:260px;height:auto;box-shadow:0 12px 28px rgba(7,25,47,.18)}.shop-product-body{padding:28px;display:flex;flex-direction:column}.product-category{color:#2e6b3a;text-transform:uppercase;font-size:12px;font-weight:950;letter-spacing:.07em}.shop-product-card h3{margin:9px 0 5px;font-size:26px;line-height:1.08}.shop-product-card h3 a{color:#123b59;text-decoration:none}.product-subtitle{font-weight:800;color:#344650}.shop-product-card p{line-height:1.6;color:#52616b}.product-meta{display:flex;gap:7px;flex-wrap:wrap;margin:10px 0 20px}.product-meta span{font-size:11px;font-weight:850;color:#123b59;background:#eef3f0;padding:7px 9px;border-radius:999px}.product-buy-row{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-top:auto}.product-buy-row strong{font-size:25px;color:#07192f}.shop-category-guide{padding-top:75px;padding-bottom:90px}.shop-product-card[hidden]{display:none!important}
@media(max-width:1050px){.shop-product-grid{grid-template-columns:1fr}.shop-product-card{grid-template-columns:220px 1fr}}@media(max-width:650px){.shop-product-card{grid-template-columns:1fr}.shop-cover-link img{max-width:220px}.product-buy-row{align-items:flex-start;flex-direction:column}.shop-library-hero{padding-top:125px}}