:root{color-scheme:light;--bg:#f5f7f8;--panel:#fff;--panel-2:#f0f4f5;--text:#182d37;--muted:#657781;--border:#e0e7ea;--accent:#087f76;--accent-soft:#e6f4f0;--paper-bg:#e6ebee;--shadow:0 12px 40px #1834400b;--physics:#4565a2;--chemistry:#a5692e;--biology:#32735a}
html[data-theme=dark]{color-scheme:dark;--bg:#101b25;--panel:#162530;--panel-2:#1d303b;--text:#e9f1f3;--muted:#a5b7c0;--border:#2c424f;--accent:#76d6bd;--accent-soft:#1c3c38;--paper-bg:#0d1821;--shadow:0 12px 40px #0002;--physics:#9ab9ee;--chemistry:#e5b477;--biology:#99d2b2}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;font-size:14px;line-height:1.5}button,input,select{font:inherit}button,a,input,select{-webkit-tap-highlight-color:transparent}button,a{touch-action:manipulation}button{cursor:pointer}button:disabled{opacity:.4;cursor:default}a{color:inherit;text-decoration:none}button{color:inherit}svg{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.65;stroke-linecap:round;stroke-linejoin:round;flex-shrink:0}.svg-library{position:absolute;width:0;height:0;overflow:hidden}[hidden]{display:none!important}:focus-visible{outline:3px solid var(--accent);outline-offset:3px;border-radius:5px}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}.skip-link{position:fixed;left:16px;top:-80px;z-index:100;padding:12px;background:var(--panel)}.skip-link:focus{top:8px}.reader-shell{height:100vh;height:100dvh;display:flex;flex-direction:column;overflow:hidden}.reader-topbar{height:78px;min-height:78px;display:flex;align-items:center;gap:32px;padding:0 36px;background:var(--panel);border-bottom:1px solid var(--border)}.brand{display:flex;gap:11px;align-items:center;min-width:210px;font-size:20px;font-weight:780;letter-spacing:-.6px}.brand-mark{width:40px;height:40px;display:grid;place-items:center;background:#183b47;color:#fff;font-size:15px;border-radius:12px;border-bottom:3px solid #67c8b0;letter-spacing:-1px}.brand small{display:block;font-size:8px;font-weight:650;letter-spacing:1.5px;color:var(--muted);margin-top:1px}.breadcrumb{display:flex;align-items:center;gap:12px;font-size:12px;color:var(--muted);min-width:0}.breadcrumb button{background:none;border:0;padding:8px 0;font-weight:650;white-space:nowrap}.breadcrumb span{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.breadcrumb span:before{content:'/';margin-right:12px;color:var(--border)}.header-actions{margin-left:auto;display:flex;gap:8px;align-items:center}.ghost-btn,.icon-btn,.primary-btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:40px;border-radius:9px;font-size:12px;font-weight:650;line-height:1.3;border:1px solid var(--border);background:var(--panel);padding:9px 13px}.icon-btn{width:40px;padding:8px;flex-shrink:0}.ghost-btn:hover,.icon-btn:hover{background:var(--panel-2)}.primary-btn{background:var(--accent);border-color:var(--accent);color:#fff}.primary-btn:hover{filter:brightness(.94)}html[data-theme=dark] .primary-btn{color:#102a26}.count{font-size:10px;font-weight:700;color:var(--muted);background:var(--panel-2);border-radius:6px;padding:2px 7px}.reader-status{padding:7px 36px;font-size:11px;color:var(--muted);background:var(--bg);min-height:30px}.reader-status:empty{display:none}.layout{display:grid;grid-template-columns:minmax(0,1fr);min-height:0;flex:1}.layout.has-book{grid-template-columns:304px minmax(0,1fr)}.workspace{min-height:0;min-width:0;overflow:auto;outline:none}.library-landing{max-width:1180px;margin:0 auto;padding:35px 48px 28px}.library-intro{display:flex;align-items:center;justify-content:space-between;gap:30px;margin-bottom:30px}.eyebrow{font-size:10px;letter-spacing:1.8px;font-weight:750;color:var(--muted);margin:0 0 9px}.library-intro h1{font-size:43px;line-height:1.12;letter-spacing:-1.9px;font-weight:730;margin:0 0 14px}.title-dot{color:var(--accent)}.intro-copy{font-size:14px;line-height:1.85;color:var(--muted);margin:0}.library-seal{display:flex;align-items:center;gap:18px;border-left:1px solid var(--border);padding-left:28px;color:var(--accent)}.library-seal svg{width:44px;height:44px;stroke-width:1}.library-seal span{font-size:9px;font-weight:750;letter-spacing:1.5px;line-height:1.9}.shelf-heading{display:flex;align-items:center;justify-content:space-between;margin:24px 0 15px;gap:12px}.shelf-heading h2{font-size:15px;font-weight:700;margin:0}.shelf-heading>span{color:var(--muted);font-size:11px}.book-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:19px}.book-card{position:relative;overflow:hidden;display:flex;flex-direction:column;padding:0;border:1px solid var(--border);background:var(--panel);border-radius:15px;text-align:left;box-shadow:var(--shadow);transition:transform .2s,box-shadow .2s}.book-card:hover{transform:translateY(-4px);box-shadow:0 14px 28px #15343e14}.book-art{position:relative;overflow:hidden;padding:21px 23px 19px;min-height:154px;width:100%;background:var(--cover);color:#fff}.book-art:before,.book-art:after{content:'';position:absolute;border:1px solid #ffffff20;border-radius:50%;width:210px;height:210px;right:-80px;top:-70px;pointer-events:none}.book-art:after{right:-40px;top:-30px;width:150px;height:150px}.book-art svg{position:absolute;width:67px;height:67px;right:25px;bottom:23px;opacity:.6;stroke-width:1}.book-art .book-edition{font-size:9px;letter-spacing:2px;color:#ffffffbd;font-weight:600}.book-art h3{font-size:24px;line-height:1.2;letter-spacing:-.7px;margin:16px 0 5px;font-weight:620}.book-class{font-size:12px;color:#ffffffd9}.book-card[data-subject=PHYSICS]{--cover:#2b4b74}.book-card[data-subject=CHEMISTRY]{--cover:#785633}.book-card[data-subject=BIOLOGY]{--cover:#275b4a}.book-card:nth-child(2n) .book-art:after{border-radius:24px;transform:rotate(30deg)}.book-card-info{display:flex;align-items:center;justify-content:space-between;padding:13px 18px;width:100%;font-size:11px;color:var(--muted)}.book-card-info strong{font-weight:650;color:var(--text)}.book-card-info svg{width:16px;height:16px;color:var(--accent)}.library-footnote{font-size:10px;color:var(--muted);margin:22px 0 0;text-align:center}.resume-card{background:var(--accent-soft);border:1px solid color-mix(in srgb,var(--accent) 20%,var(--border));border-radius:12px;display:flex;gap:16px;align-items:center;text-align:left;width:100%;padding:18px 20px}.resume-icon{background:var(--panel);border-radius:10px;width:44px;height:49px;display:grid;place-items:center;color:var(--accent)}.resume-copy{display:flex;flex-direction:column;gap:3px;min-width:0}.resume-copy small{font-size:8px;font-weight:800;letter-spacing:1.3px;color:var(--accent)}.resume-copy strong{font-size:14px;font-weight:650}.resume-copy>span{font-size:11px;color:var(--muted)}.resume-action{margin-left:auto;display:flex;gap:10px;align-items:center;font-size:11px;font-weight:700;color:var(--accent);white-space:nowrap}.chapter-pane{background:var(--panel);border-right:1px solid var(--border);display:flex;flex-direction:column;min-height:0;padding:22px 18px 0}.chapter-pane-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:9px}.subject-tabs{display:flex;gap:3px;background:var(--panel-2);border-radius:9px;padding:4px}.subject-tab{flex:1;background:none;border:0;border-radius:6px;padding:8px 5px;font-size:11px;font-weight:650;color:var(--muted)}.subject-tab.is-active{background:var(--panel);box-shadow:0 1px 5px #0000000a;color:var(--accent)}.class-tabs{display:flex;gap:8px;margin:13px 0 16px}.class-tab{flex:1;border:1px solid var(--border);background:var(--panel);font-size:11px;padding:7px;border-radius:7px}.class-tab.is-active{color:var(--accent);background:var(--accent-soft);border-color:color-mix(in srgb,var(--accent) 45%,var(--border));font-weight:700}.chapter-search{display:flex;align-items:center;gap:9px;border:1px solid var(--border);border-radius:8px;padding:0 10px;min-height:42px;color:var(--muted)}.chapter-search svg{width:16px;height:16px}.chapter-search input{background:transparent;border:0;min-width:0;width:100%;color:var(--text);font-size:12px;outline:none;height:40px}.chapter-search:focus-within{outline:2px solid var(--accent);outline-offset:2px}.list-heading{display:flex;justify-content:space-between;align-items:center;margin:20px 3px 10px}.list-heading h2{font-size:11px;margin:0;font-weight:700;letter-spacing:.3px}.chapter-list{overflow:auto;flex:1;margin:0 -7px;padding:0 7px 15px;scrollbar-width:thin;scrollbar-color:var(--border) transparent}.chapter-card{width:100%;border:1px solid transparent;background:none;border-radius:8px;display:flex;gap:11px;padding:12px 10px;margin:2px 0;text-align:left;align-items:flex-start}.chapter-card:hover{background:var(--panel-2)}.chapter-card.is-active{background:var(--accent-soft);color:var(--accent);border-color:color-mix(in srgb,var(--accent) 15%,transparent)}.chapter-number{font-size:10px;color:var(--muted);min-width:18px;line-height:1.8;font-variant-numeric:tabular-nums}.chapter-copy{display:flex;flex-direction:column;gap:4px;min-width:0}.chapter-copy strong{font-size:12px;line-height:1.55;font-weight:550}.chapter-copy small{font-size:9px;color:var(--muted)}.chapter-card.is-active .chapter-copy strong{font-weight:700}.sidebar-note{display:flex;align-items:center;justify-content:center;gap:8px;border-top:1px solid var(--border);padding:15px 0;font-size:10px;color:var(--muted);margin:0}.sidebar-note svg{width:13px;height:13px}.viewer-pane{height:100%;display:flex;flex-direction:column;min-height:0;background:var(--panel)}.reading-heading{display:flex;align-items:center;gap:18px;padding:22px 26px;min-height:96px}.chapter-title-wrap{min-width:0;flex:1}.chapter-title-wrap h1{font-size:21px;line-height:1.35;margin:0;letter-spacing:-.5px;font-weight:660;overflow-wrap:anywhere}.chapter-title-wrap .eyebrow{font-size:9px;letter-spacing:1px;margin-bottom:6px}.reading-progress{height:3px;background:var(--panel-2);flex-shrink:0}.reading-progress>span{display:block;height:100%;width:0;background:var(--accent);transition:width .2s}.viewer-toolbar{display:flex;flex-wrap:wrap;align-items:center;gap:12px;border-bottom:1px solid var(--border);padding:10px 22px;background:var(--panel)}.page-controls{display:flex;align-items:center;gap:3px;font-size:11px;color:var(--muted)}.page-controls .icon-btn{border:0;width:30px;min-height:34px}.page-controls>span{padding:0 7px 0 1px;white-space:nowrap}.viewer-toolbar input,.viewer-toolbar select{border:1px solid var(--border);background:var(--panel);color:var(--text);border-radius:7px;padding:7px;font-size:11px;min-height:35px}.viewer-toolbar #pageInput{width:47px;text-align:center;appearance:textfield;-moz-appearance:textfield}.viewer-toolbar #pageInput::-webkit-inner-spin-button{appearance:none}.zoom-controls{display:flex;gap:5px}.zoom-controls select{width:101px}#zoomCustomInput{width:62px}.viewer-toolbar .ghost-btn{font-size:11px;min-height:35px;padding:7px 10px}.toolbar-end{margin-left:auto;display:flex;gap:6px;align-items:center}.toolbar-end>.icon-btn,.reader-more>.icon-btn{min-height:35px;height:35px;width:35px;border:0}.toolbar-end .primary-btn{min-height:35px;font-size:11px;padding:8px 11px}.toolbar-end svg{width:17px;height:17px}.reader-more{position:relative}.reader-more summary{list-style:none;cursor:pointer;letter-spacing:1px}.reader-more summary::-webkit-details-marker{display:none}.more-menu{position:absolute;z-index:10;right:0;top:44px;width:225px;background:var(--panel);border:1px solid var(--border);border-radius:12px;box-shadow:0 12px 30px #0002;padding:6px}.more-menu button,.more-menu a{width:100%;display:flex;gap:10px;align-items:center;padding:12px;background:transparent;border:0;text-align:left;font-size:12px;border-radius:7px}.more-menu button:hover,.more-menu a:hover{background:var(--panel-2)}[aria-pressed=true]#bookmarkPageBtn{color:var(--accent);background:var(--accent-soft)}[aria-pressed=true]#bookmarkPageBtn svg{fill:var(--accent-soft)}.message-panel{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:42px 24px;background:var(--bg);min-height:270px}.message-icon{width:75px;height:82px;border:1px solid var(--border);border-radius:15px;background:var(--panel);box-shadow:var(--shadow);display:grid;place-items:center;color:var(--accent);margin-bottom:25px;transform:rotate(-5deg)}.message-icon svg{width:34px;height:34px;stroke-width:1.2}.message-panel h2{font-size:24px;line-height:1.3;letter-spacing:-.6px;margin:5px 0 10px;font-weight:630}.message-panel>p:not(.eyebrow){max-width:420px;margin:0;color:var(--muted);font-size:13px;line-height:1.8}.message-actions{display:flex;justify-content:center;align-items:center;flex-wrap:wrap;gap:16px;margin-top:23px}.text-link{font-size:12px;color:var(--accent);font-weight:650}.message-panel.is-loading .message-icon{animation:breathe 1.6s ease-in-out infinite}.pdf-stage{flex:1;min-height:0;overflow:auto;background:var(--paper-bg);padding:24px;text-align:center;overscroll-behavior:contain}.pdf-stage>canvas{display:block;margin:0 auto;background:#fff;box-shadow:0 3px 16px #13202e20}.pdf-scroll{display:flex;flex-direction:column;align-items:center;gap:20px;min-width:100%;width:max-content}.pdf-page-slot{display:grid;place-items:center;flex-shrink:0;position:relative;min-height:300px;color:#657781;background:#fff;box-shadow:0 3px 16px #13202e20;scroll-margin-top:24px}.pdf-page-slot>canvas{display:block}.reading-footer{display:flex;justify-content:space-between;gap:10px;border-top:1px solid var(--border);padding:10px 24px;color:var(--muted);font-size:10px;background:var(--panel)}.bookmarks-dialog{width:min(520px,calc(100% - 30px));max-height:80vh;background:var(--panel);color:var(--text);border:1px solid var(--border);padding:24px;border-radius:18px;box-shadow:0 25px 80px #0003}.bookmarks-dialog::backdrop{background:#0b223877;backdrop-filter:blur(3px)}.dialog-heading{display:flex;justify-content:space-between;gap:20px;align-items:center;margin-bottom:20px}.dialog-heading h2{font-size:23px;letter-spacing:-.7px;margin:0}.bookmark-row{display:flex;gap:10px;align-items:center;border-top:1px solid var(--border);padding:10px 0}.bookmark-jump{flex:1;border:0;background:none;text-align:left;padding:8px;border-radius:7px;display:flex;flex-direction:column;gap:4px}.bookmark-jump:hover{background:var(--panel-2)}.bookmark-jump strong{font-size:13px}.bookmark-jump span,.dialog-note{font-size:11px;color:var(--muted)}.dialog-note{margin-bottom:0}.empty-list{padding:24px 10px;color:var(--muted);font-size:12px;line-height:1.8}.shelf-loading{padding:40px;color:var(--muted);font-size:13px;grid-column:1/-1}.mobile-only{display:none}#chaptersToggle{display:none}.focus-mode .chapter-pane{display:none}.focus-mode .layout.has-book{grid-template-columns:minmax(0,1fr)}.focus-mode .reading-heading{padding-top:12px;padding-bottom:12px;min-height:72px}.focus-mode #chaptersToggle{display:inline-flex}.chapter-backdrop{border:0}.bookmarks-dialog .icon-btn{flex-shrink:0}@keyframes breathe{50%{opacity:.35;transform:rotate(-5deg) translateY(-3px)}}
@media(min-width:1600px){.layout.has-book{grid-template-columns:330px minmax(0,1fr)}.chapter-pane{padding-left:26px;padding-right:26px}}
@media(max-width:1100px){.reader-topbar{padding:0 24px;gap:20px}.brand{min-width:170px}.library-landing{padding:32px}.layout.has-book{grid-template-columns:270px minmax(0,1fr)}.viewer-toolbar{gap:7px;padding:9px 16px}.reading-heading{padding:20px}.viewer-toolbar #viewModeBtn{font-size:10px}}
@media(max-width:800px){.reader-topbar{height:68px;min-height:68px;padding:0 18px;gap:12px}.brand{min-width:0;font-size:18px}.brand-mark{width:35px;height:35px;font-size:13px}.brand small{font-size:7px}.breadcrumb{margin-left:15px}.breadcrumb span{display:none}.header-actions .ghost-btn>span{display:none}.header-actions .ghost-btn{width:36px;padding:8px;border:0}.header-actions .icon-btn{width:36px;border:0}.reader-status{padding:6px 18px}.layout.has-book{grid-template-columns:minmax(0,1fr)}.chapter-pane{position:fixed;z-index:35;inset:0 auto 0 0;width:min(340px,88vw);visibility:hidden;transform:translateX(-100%);transition:transform .2s,visibility .2s;padding-top:17px;box-shadow:15px 0 50px #0002}.chapters-open .chapter-pane{visibility:visible;transform:translateX(0)}.chapter-backdrop{position:fixed;inset:0;z-index:30;background:#0b223877;backdrop-filter:blur(2px)}.mobile-only,#chaptersToggle{display:inline-flex}.chapter-pane-head .eyebrow{margin:0}.chapter-pane-head{margin-bottom:16px}.focus-mode .chapter-pane{display:flex}.library-landing{padding:27px 25px}.library-intro h1{font-size:36px}.library-seal{padding-left:20px}.book-grid{gap:14px}.book-art{padding:18px;min-height:145px}.book-art h3{font-size:21px}.book-art svg{width:47px;height:47px;right:14px;bottom:22px;opacity:.45}.reading-heading{padding:15px 18px;gap:12px;min-height:88px}.chapter-title-wrap h1{font-size:18px}.chapter-title-wrap .eyebrow{font-size:8px}.reading-heading #chaptersToggle span{display:none}.reading-heading #chaptersToggle{width:37px;padding:8px}.message-panel h2{font-size:23px}.pdf-stage{padding:16px}.reader-more .more-menu{right:0}.resume-action{font-size:0;gap:0}.reading-footer{padding:9px 16px}.reading-footer>span:last-child{font-size:9px}}
@media(max-width:600px){.reader-topbar{padding:0 15px;gap:6px}.breadcrumb{display:flex;margin-left:auto;font-size:11px}.brand{font-size:15px;gap:7px}.brand small{display:none}.header-actions{gap:2px;margin-left:4px}.library-landing{padding:24px 18px}.library-intro{margin-bottom:24px}.library-intro h1{font-size:34px;letter-spacing:-1.5px}.intro-copy{font-size:12px}.desktop-break{display:none}.library-seal{display:none}.shelf-heading{margin-top:22px}.book-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.book-art{min-height:151px;padding:18px 16px}.book-art h3{font-size:21px;margin-top:22px}.book-art svg{width:48px;height:48px;right:12px;bottom:14px;opacity:.25}.book-card-info{padding:12px;font-size:10px;gap:5px}.book-card-info strong{display:none}.book-card-info svg{width:15px}.library-footnote{font-size:10px;line-height:1.7}.shelf-heading>span{font-size:10px}.resume-card{padding:15px 12px;gap:10px}.resume-copy strong{font-size:12px}.resume-copy small{font-size:7px}.resume-icon{width:33px;height:43px;flex-shrink:0}.resume-copy>span{font-size:10px}.resume-action{display:none}.reading-heading{padding:15px 12px;gap:10px}.chapter-title-wrap h1{font-size:17px}.reading-heading .icon-btn{width:35px;height:35px;min-height:35px}.viewer-toolbar{padding:8px 10px;gap:7px}.viewer-toolbar #viewModeBtn{margin-left:auto}.toolbar-end{width:100%;margin-left:0;justify-content:flex-end;border-top:1px solid var(--border);padding-top:7px}.toolbar-end>.icon-btn{margin-right:auto}.pdf-stage{padding:12px}.reading-footer>span:last-child{display:none}.reading-footer{justify-content:center}.message-panel{padding:35px 20px}.message-panel h2{font-size:21px}.message-panel>p:not(.eyebrow){font-size:12px}.bookmarks-dialog{padding:20px}.reader-status{font-size:10px;min-height:27px;padding:6px 15px}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

/* NEETAce science collection — dimensional scenes, clear type and quiet reading. */
:root{--bg:#edf3f8;--text:#18334b;--muted:#61778b;--border:#dce6ef;--accent:#157e95;--accent-soft:#e4f5f5;--panel-2:#f0f5fa}html[data-theme=dark]{--bg:#080f1c;--panel:#101e2d;--panel-2:#162b3d;--border:#263a50;--text:#eaf3ff;--muted:#9caec3;--accent:#77dfd0;--accent-soft:#173a3e}.reader-topbar{height:76px;min-height:76px;background:color-mix(in srgb,var(--panel) 85%,transparent);backdrop-filter:blur(20px);padding:0 34px}.brand-mark{background:linear-gradient(135deg,#195080,#153343);border-bottom-color:#69dbc7}.library-landing{max-width:1360px;padding:28px 38px 32px}.science-hero{background:radial-gradient(ellipse at 85% 30%,#144c6355,transparent 65%),linear-gradient(125deg,#0b172b,#112941);border:1px solid #588fab3b;border-radius:26px;padding:35px 42px;min-height:300px;position:relative;overflow:hidden;box-shadow:0 20px 60px #142a4614;margin-bottom:25px;color:#f0f6ff}.science-hero:before{content:'';position:absolute;inset:0;background-image:radial-gradient(#9ccef826 .7px,transparent .7px);background-size:22px 22px;pointer-events:none;mask-image:linear-gradient(90deg,transparent,#000)}.hero-copy{position:relative;z-index:1;flex:1}.science-hero .eyebrow{color:#8dddcf;font-size:9px;letter-spacing:2px;display:flex;align-items:center;gap:8px}.live-dot{width:6px;height:6px;border-radius:50%;background:#8fead5;box-shadow:0 0 12px #8fead580}.science-hero h1{font-size:43px;line-height:1.15;letter-spacing:-1.9px;font-weight:650;margin:18px 0 17px}.science-hero h1>span{color:#8bdfd2}.science-hero .intro-copy{color:#b2c4d7;font-size:13px;line-height:1.85}.hero-subjects{display:flex;gap:20px;margin-top:27px;color:#c4d6e7;font-size:9px;letter-spacing:.7px}.hero-scene-wrap{width:36%;align-self:stretch;position:relative;min-height:220px;flex-shrink:0;border:1px solid #9cecf51f;border-radius:19px;background:linear-gradient(140deg,#28445b29,#97e9e609);box-shadow:inset 0 1px 0 #d8faff12;backdrop-filter:none}science-scene.hero-scene{height:230px;width:100%;border:0;background:none;box-shadow:none;border-radius:19px;aspect-ratio:auto}.hero-scene .scene-description{display:none}.hero-scene-label{position:relative;text-align:center;padding:0 12px 16px;margin-top:-15px;pointer-events:none}.hero-scene-label span{display:block;font-size:8px;letter-spacing:1.9px;color:#79d7d1}.hero-scene-label strong{display:block;font-size:11px;font-weight:500;color:#d5e8f3;margin-top:5px}.hero-scene-label small{display:block;font-size:8px;color:#8fa6ba;margin-top:5px}.shelf-heading{align-items:flex-end;margin:27px 0 17px}.shelf-heading h2{font-size:23px;font-weight:650;letter-spacing:-.7px}.shelf-heading .eyebrow{font-size:8px;letter-spacing:1.7px;margin-bottom:5px}.shelf-actions{display:flex;align-items:center;gap:14px}.shelf-actions>span{font-size:10px;color:var(--muted)}.book-grid{gap:18px}.book-card{border-radius:20px;box-shadow:0 3px 12px #11345905;gap:0!important}.book-card:hover{transform:translateY(-4px);border-color:#74afb8;box-shadow:0 15px 35px #0b3a6b18}.book-art{background:linear-gradient(130deg,#102439,#132d47);padding:16px 19px 19px;min-height:240px}.book-art:before,.book-art:after{display:none}.book-cover-top{display:flex;justify-content:space-between;align-items:center;position:relative;z-index:2}.book-art .book-edition{font-size:8px;letter-spacing:1.6px;color:#a6bed1}.book-class{font-size:9px;padding:3px 8px;border-radius:99px;border:1px solid #e1f4ff29;color:#c9e2ef;background:#abc5db09}science-scene.book-scene{height:142px;width:100%;background:transparent;border:0;border-radius:0;box-shadow:none;aspect-ratio:auto}.book-scene .scene-description{display:none}.book-cover-title h3{margin:0 0 4px;font-size:24px;font-weight:580}.book-cover-title>span{font-size:10px;color:#a8bfd1}.book-card[data-subject=CHEMISTRY] .book-art{background:linear-gradient(130deg,#162637,#253541)}.book-card[data-subject=BIOLOGY] .book-art{background:linear-gradient(130deg,#102c36,#143e42)}.book-card-info{padding:14px 18px;font-size:10px}.book-card-info strong{font-size:10px;font-weight:650}.book-card-info svg{background:var(--accent-soft);box-sizing:content-box;padding:5px;border-radius:50%;width:15px;height:15px}.chapter-pane{padding:20px 12px 0}.chapter-pane-head,.chapter-pane .subject-tabs,.chapter-pane .class-tabs,.chapter-search{margin-left:5px;margin-right:5px}.chapter-card{padding:9px 6px;gap:7px;align-items:center}.chapter-card .scene-thumb{width:43px;height:45px;flex-basis:43px;border-radius:10px}.chapter-number{min-width:14px;font-size:9px}.chapter-copy strong{font-size:11px}.reading-heading{gap:12px}.reading-heading>.scene-thumb{width:60px;height:58px;flex-basis:60px}.resume-card{background:linear-gradient(110deg,var(--accent-soft),var(--panel));border-radius:16px;padding:18px 21px}.reader-status{font-size:11px}.library-footnote{font-size:10px}.message-icon{background:linear-gradient(145deg,var(--panel),var(--accent-soft));border-radius:22px}.pdf-stage{background:var(--paper-bg)}
@media(max-width:1100px){.science-hero{padding:27px}.science-hero h1{font-size:35px}.hero-scene-wrap{width:36%}.library-landing{padding:25px}.book-art{padding:14px 16px 17px}}
@media(max-width:800px){.reader-topbar{padding:0 18px;height:68px;min-height:68px}.science-hero{gap:16px;min-height:270px}.science-hero h1{font-size:30px;letter-spacing:-1.2px}.hero-subjects{gap:12px;font-size:8px}.hero-scene-wrap{width:34%}.hero-scene-label strong{font-size:9px}.hero-scene-label span{font-size:7px}.science-hero .intro-copy{font-size:12px}.shelf-heading h2{font-size:20px}.shelf-actions{flex-direction:column;align-items:flex-end;gap:5px}.book-art{min-height:220px}.book-cover-title h3{font-size:21px}.book-cover-title>span{font-size:9px}}
@media(max-width:600px){.library-landing{padding:17px 14px 25px}.science-hero{padding:23px 22px 18px;border-radius:21px;display:block}.science-hero h1{font-size:31px;line-height:1.18;margin:14px 0}.science-hero .eyebrow{font-size:8px;letter-spacing:1.6px}.hero-subjects{margin-top:19px;justify-content:space-between}.hero-scene-wrap{margin-top:22px;width:100%;min-height:0;display:flex;align-items:center}.hero-scene-wrap science-scene{height:132px;width:47%;flex-shrink:0}.hero-scene-label{text-align:left;margin:0;padding:12px 10px 12px 0}.hero-scene-label strong{font-size:11px;line-height:1.5}.hero-scene-label small{font-size:8px;line-height:1.4}.hero-scene-label span{font-size:7px;letter-spacing:1.4px}.book-grid{gap:12px}.book-art{padding:12px 13px 15px;min-height:217px}.book-art .book-edition{font-size:7px;letter-spacing:1px}.book-class{font-size:8px;padding:3px 6px}.book-scene{height:126px!important}.book-cover-title h3{font-size:21px}.book-cover-title>span{font-size:9px;display:block;line-height:1.4;min-height:25px}.book-card-info{padding:10px 12px}.book-card-info strong{display:none}.book-card-info svg{padding:4px;width:12px;height:12px}.shelf-heading h2{font-size:19px}.shelf-actions>span{font-size:9px}.science-motion{font-size:10px;padding:6px 10px;min-height:32px}.shelf-heading{gap:7px}.shelf-heading .eyebrow{font-size:7px}.reading-heading>.scene-thumb{width:42px;height:44px;flex-basis:42px}.reading-heading{gap:8px}.chapter-title-wrap h1{font-size:15px}.chapter-title-wrap .eyebrow{font-size:7px}.reader-topbar .brand{font-size:14px;gap:6px}.reader-topbar .brand-mark{width:30px;height:32px}.reader-topbar .breadcrumb{font-size:10px;margin-left:auto}.reader-topbar{padding:0 12px}.reader-topbar .header-actions{margin-left:3px}}

/* ---- Elevated visual system: type, atmosphere, motion, tactile detail ---- */
:root{--font-body:'Hanken Grotesk','Inter',ui-sans-serif,system-ui,-apple-system,sans-serif;--font-display:'Bricolage Grotesque','Plus Jakarta Sans',var(--font-body)}
body{font-family:var(--font-body)}
.library-intro h1,.science-hero h1,.book-cover-title h3,.chapter-title-wrap h1,.message-panel h2,.dialog-heading h2,.resume-copy strong,.brand{font-family:var(--font-display);letter-spacing:-.02em}

.library-landing{position:relative}
.library-landing:before{content:'';position:fixed;inset:0;z-index:-1;pointer-events:none;background:radial-gradient(1100px 620px at 82% -8%,color-mix(in srgb,var(--accent) 14%,transparent),transparent 60%),radial-gradient(900px 520px at -10% 25%,color-mix(in srgb,var(--physics) 12%,transparent),transparent 55%)}
html[data-theme=dark] .library-landing:before{background:radial-gradient(1100px 620px at 82% -8%,#1c5a6a4d,transparent 60%),radial-gradient(900px 520px at -10% 25%,#16324f45,transparent 55%)}

.science-hero{isolation:isolate}
.science-hero:after{content:'';position:absolute;inset:-35% -8% auto auto;width:400px;height:400px;border-radius:50%;background:radial-gradient(circle,#59e6cf2e,transparent 70%);z-index:0;pointer-events:none;animation:aurora-drift 16s ease-in-out infinite}
.science-hero>*{position:relative;z-index:1}
@keyframes aurora-drift{0%,100%{transform:translate(0,0) scale(1)}50%{transform:translate(-26px,22px) scale(1.1)}}

.book-card{animation:card-rise .5s cubic-bezier(.2,.7,.3,1) both;border-color:color-mix(in srgb,var(--cover,var(--accent)) 24%,var(--border))}
.book-card:nth-child(1){animation-delay:.02s}.book-card:nth-child(2){animation-delay:.06s}.book-card:nth-child(3){animation-delay:.1s}.book-card:nth-child(4){animation-delay:.14s}.book-card:nth-child(5){animation-delay:.18s}.book-card:nth-child(6){animation-delay:.22s}
@keyframes card-rise{from{opacity:0;transform:translateY(14px) scale(.98)}to{opacity:1;transform:none}}
.book-card:hover{box-shadow:0 18px 40px -14px color-mix(in srgb,var(--cover,var(--accent)) 60%,transparent),0 4px 14px #0002}

.chapter-card{transition:background .15s,transform .15s}
.chapter-card:hover{transform:translateX(2px)}
.chapter-card.is-active{position:relative}
.chapter-card.is-active:before{content:'';position:absolute;left:-7px;top:9px;bottom:9px;width:3px;border-radius:99px;background:linear-gradient(var(--accent),color-mix(in srgb,var(--accent) 35%,transparent))}

.primary-btn{background:linear-gradient(135deg,var(--accent),color-mix(in srgb,var(--accent) 78%,#000 12%));box-shadow:0 6px 18px -8px color-mix(in srgb,var(--accent) 65%,transparent);transition:transform .15s,box-shadow .15s,filter .15s}
.primary-btn:hover{transform:translateY(-1px);box-shadow:0 10px 24px -8px color-mix(in srgb,var(--accent) 72%,transparent);filter:none}
.science-motion,.ghost-btn,.icon-btn{transition:box-shadow .15s,transform .15s,background .15s}
.science-motion:hover,.ghost-btn:hover{box-shadow:0 4px 14px #00000012;transform:translateY(-1px)}
/* Toolbar buttons respond only to their own hover/press - never a synced or
   looping animation across the row, so a 6-icon toolbar stays cheap to render
   and never fights for the student's attention. */
.ghost-btn:active,.icon-btn:active,.primary-btn:active{transform:scale(.93)}
/* Photographic book covers. The art is a square render on its own dark ground,
   so it is bled to the full card and the flat --cover colour becomes the frame
   it sits in. The scrim only darkens the lower half, where the title sits -
   without it white text lands on whatever the render happens to be bright at. */
/* The photo is taken out of flow, so the art box can no longer be sized by its
   contents the way the in-flow canvas scene sized it. Height is restated and
   the two text blocks are pinned to top and bottom, otherwise the title rides
   up over the artwork. */
.book-card.has-photo .book-art{position:relative;display:flex;flex-direction:column;justify-content:space-between;min-height:252px}
.book-photo{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;object-position:center 42%;opacity:.92;z-index:0}
.book-card.has-photo .book-art:before{content:'';position:absolute;inset:0;z-index:1;background:linear-gradient(180deg,color-mix(in srgb,var(--cover) 45%,transparent) 0%,transparent 30%,color-mix(in srgb,#04121b 58%,transparent) 64%,color-mix(in srgb,#04121b 93%,transparent) 100%)}
.book-card.has-photo .book-cover-top,.book-card.has-photo .book-cover-title{position:relative;z-index:2}
.book-card.has-photo .book-art:after{display:none}
.book-card.has-photo .book-photo{transition:transform .35s ease}
.book-card.has-photo:hover .book-photo{transform:scale(1.04)}
@media(prefers-reduced-motion:reduce){.book-card.has-photo:hover .book-photo{transform:none}}
.viewer-toolbar{animation:toolbar-in .22s ease-out both}
@keyframes toolbar-in{from{opacity:0;transform:translateY(-4px)}to{opacity:1;transform:none}}

.message-icon{position:relative;overflow:visible}
.message-icon:before{content:'';position:absolute;inset:-20px;border-radius:50%;background:radial-gradient(circle,color-mix(in srgb,var(--accent) 22%,transparent),transparent 70%);z-index:-1}

.resume-card{transition:transform .15s,box-shadow .15s}
.resume-card:hover{transform:translateY(-2px);box-shadow:0 12px 28px -10px color-mix(in srgb,var(--accent) 45%,transparent)}

.chapter-list::-webkit-scrollbar,.pdf-stage::-webkit-scrollbar{width:9px;height:9px}
.chapter-list::-webkit-scrollbar-thumb,.pdf-stage::-webkit-scrollbar-thumb{background:var(--border);border-radius:99px}
.chapter-list::-webkit-scrollbar-thumb:hover,.pdf-stage::-webkit-scrollbar-thumb:hover{background:var(--muted)}

@media(prefers-reduced-motion:reduce){.science-hero:after{animation:none}.book-card{animation:none}}

.skeleton-card{animation:none!important;min-height:290px;background:linear-gradient(100deg,var(--panel-2) 30%,color-mix(in srgb,var(--panel-2) 40%,var(--panel)) 50%,var(--panel-2) 70%);background-size:220% 100%;animation:skeleton-sweep 1.5s ease-in-out infinite!important;box-shadow:none}
@keyframes skeleton-sweep{0%{background-position:120% 0}100%{background-position:-20% 0}}
@media(prefers-reduced-motion:reduce){.skeleton-card{animation:none!important;opacity:.6}}