/* Compact cards retain the exact reference artwork and its aspect ratio. */
:root{background:#f5f7fa;--line:#e1e8ef;--muted:#6a7c8e;color:#21384b}
.sidebar{width:220px;padding:24px 16px;background:#fff;border-color:#e4eaf0}.shell{margin-left:220px}.brand{font-size:19px;gap:9px}.sidebar>.eyebrow{margin:28px 10px 12px;font-size:10px;letter-spacing:1.4px}.sidebar nav{gap:4px}.sidebar nav a{padding:10px;gap:9px;font-size:13px;border-radius:8px;line-height:1.45}.sidebar nav a.active{background:#eaf4ff;color:#177ac0}.nav-icon{font-size:18px}.side-bottom{padding:20px 8px 0}.mini-grid{max-width:142px;margin:auto;padding:10px}.side-bottom p{font-size:12px}.author{margin-top:18px;padding-top:15px;font-size:12px}.author small{font-size:11px}
.shell header{height:62px;padding:0 30px;background:#fff;border-bottom:1px solid #e4eaf0;color:#304f66}.shell #breadcrumb{color:#526d80;font-size:13px}.language{background:#f1f5f9;border-color:#e0e8ef}.language button{color:#6c8091;padding:8px 11px;min-height:34px}.language button.active{color:#1278bd;box-shadow:0 1px 4px #183b5710}.shell main{max-width:1170px;padding:26px 30px 38px}.shell h1{font-size:clamp(24px,2.5vw,30px);letter-spacing:-.6px;margin-bottom:8px}.shell .intro{margin-bottom:23px;gap:16px}.shell .intro .eyebrow{font-size:10px;margin-bottom:9px;letter-spacing:1.6px;color:#238dae}.shell .sub{font-size:14px;line-height:1.65}.shell .number{font-size:36px}.shell .count{min-width:70px}.shell .count small{font-size:11px}
.home-group{margin:20px 0 24px}.home-group h2{display:flex;align-items:center;gap:10px;font-size:15px;letter-spacing:0;margin-bottom:11px;color:#3c576c}.home-group h2:after{content:'';height:1px;flex:1;background:#e0e8ef;margin-left:5px}.tile-grid{gap:12px}.tile{display:flex;align-items:center;gap:14px;padding:15px;background:#fff;border:1px solid #e0e8ef;border-radius:12px;box-shadow:0 2px 5px #25445c03;min-width:0}.tile:hover{border-color:#9cc7e4;box-shadow:0 5px 16px #25445c0a;transform:translateY(-2px)}.tile>.reference-picture{width:96px;height:auto;border-radius:7px;flex:none}.tile .tile-art,.resources .tile-art{width:72px;height:65px;flex:none;border-radius:9px;font-size:28px;letter-spacing:0}.tile-copy{padding:0;background:transparent;min-width:0;flex:1}.tile h3{font-size:15px;line-height:1.5;color:#243f54;overflow-wrap:anywhere}.tile p{font-size:12px;line-height:1.55;margin:5px 0 0;color:#708596}.tile small{position:static;display:inline-block;font-size:12px;margin-top:6px;color:#4894c3}.resources{grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.resources .tile{gap:11px;padding:13px}.resources .tile>.reference-picture{width:68px}.resources .tile h3{font-size:14px}.resources .tile p{font-size:12px}.resources .tile-art{width:60px;height:60px;font-size:25px}
.reference-formula-grid{gap:12px;margin-bottom:20px}.reference-formula-grid figure{background:#fff;border-color:#e0e8ef;border-radius:12px}.reference-formula-grid .formula-book-link{padding:14px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:12px}.reference-formula-grid .reference-picture{width:min(100%,160px);border-radius:7px}.reference-formula-grid figcaption{padding:0;font-size:13px;text-align:center;line-height:1.5}.reference-formula-grid figcaption small{font-size:11px;margin-top:3px;color:#7a8e9e}.formula-book-link:hover{background:#f5faff}
.book-grid{grid-template-columns:repeat(4,minmax(0,1fr));gap:13px}.book-card{border-color:#e0e8ef;border-radius:11px}.cover-wrap{height:164px;padding:12px;background:#eef3f7}.cover-wrap img{height:140px}.book-copy{padding:13px}.book-copy h3{font-size:13px;line-height:1.55;margin:9px 0 0}.book-copy p{font-size:11px;margin:6px 0 12px}.book-copy .tag{font-size:10px;padding:4px 7px}.book-open{font-size:12px}.section-bar{margin:16px 0;gap:10px}.chips{gap:6px}.chips button{padding:9px 12px;font-size:12px;min-height:40px}.source-note{font-size:12px;margin-top:20px}.topic-grid{gap:13px}.topic-card{padding:17px;border-color:#e0e8ef;box-shadow:none}.topic-card .card-top{margin-bottom:13px}.topic-card h2{font-size:15px;line-height:1.5}.topic-card p{font-size:12px;margin-bottom:16px}.tag{font-size:10px;padding:5px 7px}.pdf-actions{gap:10px}.link-button{font-size:12px;padding:10px 12px}.download-link{font-size:12px}.test-reference{max-width:190px;margin-bottom:16px}.author-card{max-width:500px}.shell footer{margin:0 30px;font-size:11px;padding:18px 0}
@media(min-width:1500px){.book-grid{grid-template-columns:repeat(5,minmax(0,1fr))}}
@media(min-width:761px) and (max-width:1100px){.sidebar{width:200px;padding:22px 12px}.shell{margin-left:200px}.shell main{padding:24px}.shell header{padding:0 24px}.resources{grid-template-columns:repeat(2,minmax(0,1fr))}.tile>.reference-picture{width:76px}.tile{gap:11px;padding:13px}.book-grid{grid-template-columns:repeat(3,minmax(0,1fr))}}
@media(max-width:760px){.sidebar{position:static;width:auto;padding:13px 16px 0;border-right:0}.sidebar .brand{font-size:18px}.sidebar nav{display:flex;gap:4px;margin:12px -16px 0;padding:0 10px 4px;overflow-x:auto}.sidebar nav a{flex:0 0 auto;font-size:12px;padding:10px 11px;min-height:40px;border-radius:8px;gap:6px}.shell{margin-left:0}.shell header{height:54px;padding:0 16px}.shell main{padding:21px 16px 30px}.shell .intro{margin-bottom:20px}.shell h1{font-size:25px}.shell .sub{font-size:13px}.home-group{margin:19px 0 22px}.home-group h2{font-size:14px}.tile-grid{gap:10px}.tile{flex-direction:column;align-items:flex-start;padding:12px;gap:10px}.tile>.reference-picture{width:82px;align-self:center}.tile-copy{width:100%}.tile h3{font-size:13px}.tile p{font-size:11px}.tile .tile-art{width:66px;height:50px;font-size:25px;align-self:center}.tile small{display:none}.resources{grid-template-columns:repeat(2,minmax(0,1fr))}.resources .tile{padding:12px;gap:10px}.resources .tile>.reference-picture{width:74px}.resources .tile h3{font-size:13px}.resources .tile p{font-size:11px}.reference-formula-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.reference-formula-grid .formula-book-link{padding:12px;gap:10px}.reference-formula-grid .reference-picture{width:118px}.reference-formula-grid figcaption{font-size:12px}.book-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:11px}.cover-wrap{height:151px;padding:10px}.cover-wrap img{height:131px}.book-copy{padding:11px}.topic-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.topic-card{padding:13px}.topic-card h2{font-size:14px}.pdf-actions{gap:12px}.shell footer{margin:0 16px}.author-card>.reference-picture{margin:-28px -17px 24px;width:calc(100% + 34px)}}
@media(max-width:420px){.topic-grid{grid-template-columns:1fr}.tile{padding:11px}.tile>.reference-picture{width:74px}.shell h1{font-size:23px}}
@media(prefers-reduced-motion:reduce){.tile:hover{transform:none}}

.collection-picture img{position:static;width:100%;height:100%;object-fit:contain}