/* Lumen: one light motif, four editorial covers. Vector art is intentionally
   separate from the project's cartoon mnemonic / story illustrations. */
.lumen-brand{display:inline-flex;align-items:center;gap:14px;color:var(--green);width:fit-content}
.lumen-mark{width:49px;height:53px;display:grid;place-items:center;flex:none;background:#365841;color:#eed493;border-radius:13px 4px 13px 4px;box-shadow:inset 0 0 0 1px #ffffff15}
.lumen-mark>svg{width:39px;height:39px;stroke:none;fill:currentColor}
.lumen-brand-copy{display:block}.lumen-brand-copy>b{display:block;font:700 30px/1.35 var(--serif);letter-spacing:1px;white-space:nowrap}.lumen-brand-copy>small{display:block;font-size:11px;letter-spacing:2px;color:var(--muted);margin-top:5px}
.sidebar .sidebar-brand{display:block;padding:0 7px}.sidebar-brand .lumen-mark{width:36px;height:37px;margin-bottom:12px;border-radius:9px 3px}.sidebar-brand .lumen-mark svg{width:29px;height:29px}.sidebar-brand .lumen-brand-copy>b{font-size:25px;letter-spacing:0;line-height:1.4}.sidebar-brand .lumen-brand-copy>small{font-size:10px;letter-spacing:1.2px;margin-top:5px}
.sidebar .nav-caption{margin-top:31px}.book-switch-link{display:flex;align-items:center;justify-content:space-between;gap:8px;color:var(--green);font-size:11px;padding:10px 1px;margin-top:11px;min-height:38px}.book-switch-link svg{width:15px;height:15px}
.book-breadcrumb{display:flex;align-items:center;gap:9px;font-size:12px;color:var(--muted);white-space:nowrap}.book-breadcrumb>a{display:flex;align-items:center;gap:5px;padding:8px 0;min-height:40px;color:var(--green)}.book-breadcrumb>a:hover{text-decoration:underline;text-underline-offset:4px}.book-breadcrumb>svg{width:13px;height:13px;color:#8b9a81}.book-breadcrumb>b{font-weight:500}.mobile-lumen-brand{display:none}
.book-breadcrumb>.back-to-books{gap:8px;padding:10px 16px;min-height:44px;border:1px solid #2e4e36;border-radius:7px;background:var(--green);color:#fffbed;font-size:14px;font-weight:700;box-shadow:0 3px 7px #283c3110}.book-breadcrumb>.back-to-books:hover{background:#2e4e36;text-decoration:none}.back-to-books>svg{width:18px;height:18px}
.book-library{height:100dvh;overflow:auto;background:var(--canvas);scrollbar-gutter:stable}
.book-library-header{max-width:1240px;padding:22px 48px 19px;margin:auto;display:flex;align-items:center;justify-content:space-between;gap:22px;border-bottom:1px solid var(--line)}
.book-library-tools{display:flex;align-items:center;gap:26px;color:var(--muted);font-size:12px;letter-spacing:1px}.book-library-tools .icon-button{border:1px solid var(--line);background:#ffffff45}
.book-library-main{max-width:1240px;margin:auto;padding:26px 48px 22px;outline:none}
.book-library-intro{display:flex;justify-content:space-between;gap:30px;align-items:center;margin-bottom:24px}.book-library-eyebrow{font-size:10px;letter-spacing:2px;color:var(--muted);display:flex;gap:16px;align-items:center;margin-bottom:11px}.book-library-eyebrow>span{letter-spacing:1px;padding-left:16px;border-left:1px solid #b5c3a9}.book-library-intro h1{font:700 38px/1.5 var(--serif);letter-spacing:1px}.book-library-intro h1>em{font-weight:400;color:var(--green);font-style:normal}.book-library-intro p{font-size:12px;color:var(--muted);margin-top:10px;line-height:1.9}
.library-light-note{display:flex;align-items:center;gap:17px;padding-right:8px;color:#697957;font-size:12px;line-height:2;letter-spacing:3px}.library-light-note .lumen-mark{width:72px;height:72px;border-radius:50%;background:#e8e5c9;color:#9c793b;box-shadow:0 0 0 8px #e8e5c940}.library-light-note .lumen-mark svg{width:53px;height:53px}
.book-shelf-heading{display:flex;justify-content:space-between;align-items:center;margin-bottom:24px;padding-top:18px;border-top:1px solid var(--line);gap:16px}.book-shelf-heading h2{font-size:14px;letter-spacing:1px}.book-shelf-heading>span{font-size:11px;color:var(--muted)}
.exam-book-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:33px}
.exam-book{display:block;min-width:0}.exam-book:focus-visible{outline-offset:10px;border-radius:3px}.book-cover-stage{position:relative;margin-bottom:22px;padding:0 6px 9px 2px;perspective:1200px}
.book-cover-stage:after{content:'';position:absolute;bottom:0;left:-6px;right:-6px;height:6px;border-top:1px solid #d0d9c6;background:#e0e6d6;border-radius:2px;box-shadow:0 5px 6px #3143300c}
.book-shelf-shadow{position:absolute;bottom:6px;left:7%;width:88%;height:13px;background:#25372624;border-radius:50%;filter:blur(6px);z-index:0}
.book-cover{position:relative;aspect-ratio:3/4.15;overflow:hidden;z-index:1;border-radius:2px 8px 8px 2px;box-shadow:inset 7px 0 0 #00000012,inset 9px 0 1px #ffffff0a,4px 3px 0 #f3edda,5px 3px 0 #c6c2aa,8px 10px 16px #203b241c;background:var(--cover-bg);color:var(--cover-ink);padding:18px 19px 16px 22px;display:flex;flex-direction:column;transform-origin:left center;transition:transform .25s,box-shadow .25s}
.book-cover:after{content:'';pointer-events:none;position:absolute;inset:0;border:1px solid #fff2;border-left:1px solid #0002;border-radius:inherit}
.cover-ielts{--cover-bg:#315c46;--cover-ink:#f2e9cd}.cover-cet4{--cover-bg:#b96b49;--cover-ink:#fff0d4}.cover-cet6{--cover-bg:#294c66;--cover-ink:#e8e9cc}.cover-postgrad{--cover-bg:#655065;--cover-ink:#f6e6c8}
.cover-imprint{display:flex;justify-content:space-between;align-items:center;font:9px/1 var(--sans);letter-spacing:2px;padding-bottom:14px;border-bottom:1px solid #ffffff3b}.cover-imprint>span:last-child{font:italic 12px var(--latin);letter-spacing:0}
.cover-title{position:relative;z-index:2;margin-top:15px}.cover-title>b{font:43px/1.1 var(--latin);letter-spacing:-1px;display:block}.cover-title>strong{font:700 19px/1.6 var(--serif);display:block;letter-spacing:2px;margin-top:5px}.cover-title>span{font-size:9px;letter-spacing:1.3px;display:block;margin-top:5px;opacity:.88}
.book-cover .cover-art{position:absolute;bottom:30px;left:0;width:100%;height:auto;max-height:46%;stroke:none;fill:none;z-index:1}
.cover-footer{position:relative;z-index:2;margin-top:auto;display:flex;justify-content:space-between;align-items:center;gap:6px;font-size:8px;letter-spacing:.5px;padding-top:8px;border-top:1px solid #ffffff30}
.available-book:hover .book-cover{transform:rotateY(-7deg) translateY(-5px);box-shadow:inset 7px 0 0 #00000012,inset 9px 0 1px #ffffff0a,4px 3px 0 #f3edda,5px 3px 0 #c6c2aa,12px 15px 22px #203b2430}
.exam-book-heading{display:flex;align-items:center;justify-content:space-between;gap:10px}.exam-book-heading h3{font:700 21px/1.5 var(--serif)}.book-availability{flex:none;font-size:10px;color:#766b5c;background:#ebe5d7;border:1px solid #d7cdb8;border-radius:4px;padding:2px 7px;white-space:nowrap}.book-availability.open{background:#e1ead6;border-color:#b7c9a7;color:#3d5e32}
.exam-book-note{font-size:11px;color:var(--muted);margin-top:8px;line-height:1.8}.exam-book-action{display:flex;justify-content:space-between;align-items:center;min-height:42px;margin-top:12px;padding:9px 12px;border:1px solid #c1d0b5;background:#e4eddc;border-radius:6px;font-size:12px;font-weight:700;color:var(--green)}.exam-book-action svg{width:17px;height:17px}.available-book:hover .exam-book-action{background:var(--green);border-color:var(--green);color:#fff8e5}.upcoming-book .exam-book-action{background:transparent;border:0;border-top:1px solid var(--line);border-radius:0;color:#7b7d71;font-size:10px;font-weight:400;padding-left:0}
.book-library-foot{display:flex;justify-content:space-between;gap:20px;align-items:center;border-top:1px solid var(--line);margin-top:31px;padding-top:19px;color:var(--muted);font-size:10px;line-height:1.9}.book-library-foot p>b{color:var(--green);font-weight:700}.book-library-foot>span{letter-spacing:1.5px;white-space:nowrap}
.mastery-book.lumen-book-mini{background:none;padding:0;border:0;box-shadow:none;width:79px;height:109px;overflow:visible;border-radius:0}.cover-mini{height:100%;width:100%;padding:8px 8px 6px 10px;box-shadow:inset 3px 0 #0002,2px 1px 0 #ede9d9,3px 1px 0 #b8c5a9,3px 4px 7px #203b241a;border-radius:1px 4px 4px 1px}.cover-mini .cover-imprint,.cover-mini .cover-title>span,.cover-mini .cover-footer{display:none}.cover-mini .cover-title{margin:0}.cover-mini .cover-title>b{font:17px/1.15 var(--latin);letter-spacing:0;color:var(--cover-ink)}.cover-mini .cover-title>strong{font:9px/1.6 var(--sans);letter-spacing:0;color:var(--cover-ink);margin-top:3px}.cover-mini .cover-art{bottom:0;max-height:65%}
@media(min-width:761px) and (max-width:1080px){.book-library-header{padding:25px 30px 22px}.book-library-main{padding:30px}.exam-book-grid{gap:24px}.book-cover{padding:15px 14px 12px 18px}.cover-title>b{font-size:35px}.cover-title>strong{font-size:16px;letter-spacing:1px}.cover-title>span{font-size:8px;letter-spacing:.5px}.cover-imprint{padding-bottom:10px;font-size:8px}.cover-title{margin-top:11px}.cover-footer{font-size:7px;letter-spacing:0}.cover-footer>span:last-child{display:none}.exam-book-heading h3{font-size:19px}.exam-book-heading{gap:5px}.book-availability{font-size:9px;padding:2px 5px}.book-library-intro h1{font-size:33px}.library-light-note{font-size:10px;gap:12px;letter-spacing:1px}.library-light-note .lumen-mark{height:57px;width:57px}}
@media(max-width:760px){
  .sidebar .sidebar-brand{display:none}.book-breadcrumb{display:none}.topbar .preview-label{display:none}.mobile-lumen-brand{display:flex;align-items:center;gap:7px;min-width:0;color:var(--green)}.mobile-lumen-brand>svg{width:15px;height:15px}.mobile-lumen-brand>b{font:700 19px/1.3 var(--serif);white-space:nowrap}.mobile-lumen-brand>small{font-size:9px;color:var(--muted);border-left:1px solid var(--line);padding-left:7px;white-space:nowrap}.topbar{gap:6px}.top-actions{gap:1px}.sidebar .nav-caption{display:none}
  .book-library{scrollbar-gutter:auto}.book-library-header{padding:23px 20px 19px;gap:10px}.book-library-header .lumen-brand{gap:10px}.book-library-header .lumen-mark{width:36px;height:40px;border-radius:10px 3px}.book-library-header .lumen-mark svg{height:30px;width:30px}.book-library-header .lumen-brand-copy>b{font-size:22px;letter-spacing:0}.book-library-header .lumen-brand-copy>small{font-size:9px;letter-spacing:1px;margin-top:3px}.book-library-tools{gap:0}.book-library-tools>span{display:none}.book-library-tools .icon-button{height:38px;width:38px}
  .book-library-main{padding:25px 20px 23px}.book-library-intro{margin-bottom:21px}.book-library-eyebrow{font-size:8px;letter-spacing:1.2px;gap:10px;margin-bottom:11px}.book-library-eyebrow>span{padding-left:10px;font-size:9px}.book-library-intro h1{font-size:29px;line-height:1.55;letter-spacing:0}.book-library-intro h1>em{display:block}.book-library-intro p{font-size:11px;margin-top:10px;max-width:300px;line-height:1.9}.library-light-note{display:none}.book-shelf-heading{padding-top:16px;margin-bottom:19px;gap:8px}.book-shelf-heading h2{font-size:12px;letter-spacing:0}.book-shelf-heading>span{font-size:9px}
  .exam-book-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:27px 20px}.book-cover-stage{padding-right:4px;padding-bottom:7px;margin-bottom:15px}.book-cover{padding:12px 10px 10px 14px;box-shadow:inset 5px 0 #00000012,3px 2px 0 #f3edda,4px 2px 0 #c6c2aa,6px 8px 12px #203b241a;border-radius:1px 5px 5px 1px}.cover-imprint{font-size:7px;letter-spacing:1.3px;padding-bottom:8px}.cover-imprint>span:last-child{font-size:9px}.cover-title{margin-top:10px}.cover-title>b{font-size:30px;letter-spacing:-.7px}.cover-title>strong{font-size:14px;letter-spacing:.5px;line-height:1.5;margin-top:4px}.cover-title>span{display:none}.book-cover .cover-art{bottom:24px;max-height:40%}.cover-footer{font-size:6px;letter-spacing:0;padding-top:6px}.cover-footer>span:last-child{display:none}.book-cover-stage:after{left:-2px;right:-2px;height:4px}.exam-book-heading{gap:6px}.exam-book-heading h3{font-size:17px}.book-availability{font-size:8px;padding:2px 5px}.exam-book-note{font-size:9px;margin-top:6px;line-height:1.8;min-height:32px}.exam-book-action{font-size:11px;min-height:42px;margin-top:8px;padding:9px 10px}.exam-book-action svg{width:16px;height:16px}.upcoming-book .exam-book-action{font-size:9px}.book-library-foot{display:block;margin-top:25px;padding-top:17px;font-size:10px}.book-library-foot>span{display:block;margin-top:11px;font-size:8px;letter-spacing:1px}.mastery-book.lumen-book-mini{width:61px;height:86px}.cover-mini{padding:7px 6px 5px 8px}.cover-mini .cover-title>b{font-size:14px}.cover-mini .cover-title>strong{font-size:7px}.book-cover.cover-mini .cover-art{bottom:0;max-height:65%}
}
@media(min-width:761px) and (max-width:1080px){.mastery-book .cover-mini{padding:8px 8px 6px 10px}}
@media(min-width:761px) and (max-width:950px){.book-cover:not(.cover-mini) .cover-title>b{font-size:30px}.book-cover:not(.cover-mini) .cover-title>strong{font-size:14px;letter-spacing:.5px}.book-cover:not(.cover-mini) .cover-title>span{display:none}.book-cover:not(.cover-mini) .cover-art{max-height:36%}}
@media(max-width:760px){.topbar .book-breadcrumb{display:flex;flex:none}.topbar .book-breadcrumb>svg,.topbar .book-breadcrumb>b{display:none}.book-breadcrumb>.back-to-books{padding:8px 10px;min-height:40px;font-size:12px;gap:5px}.back-to-books>svg{width:15px;height:15px}.mobile-lumen-brand>b{font-size:16px}.topbar{gap:9px}.top-actions{gap:1px}.top-actions .search-trigger,.top-actions>.icon-button{width:30px}.topbar .top-actions{margin-left:auto}}
@media(max-width:365px){.mobile-lumen-brand>b{font-size:15px}.mobile-lumen-brand>small{font-size:8px;padding-left:5px}.topbar{padding-left:13px;padding-right:11px}.top-actions .search-trigger{width:34px}.top-actions>.icon-button{width:34px}.book-library-header{padding-left:16px;padding-right:16px}.book-library-header .lumen-brand-copy>b{font-size:21px}.book-library-main{padding-left:16px;padding-right:16px}.exam-book-grid{gap:24px 16px}.cover-title>b{font-size:28px}.cover-title>strong{font-size:13px}.exam-book-heading h3{font-size:16px}.book-availability{padding:2px 4px}.book-library-intro h1{font-size:28px}}