/* Existing Topperly flow geometry; visual declarations removed. */
*{box-sizing:border-box}html,body,#app{height:100%;margin:0}a{text-decoration:none}button{cursor:pointer}button:disabled{cursor:default;opacity:.5}button svg{width:18px;height:18px}.boot{display:grid;place-items:center;height:100%}.skip-link{position:fixed;top:-60px;left:240px;z-index:100;padding:10px}.skip-link:focus{top:12px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}.top-avatar{width:29px;height:29px}.text-link{display:inline-flex;align-items:center;gap:7px}.panel{overflow:hidden}.panel-caption{padding:12px 15px;display:flex;align-items:center;justify-content:space-between}.progress-list{padding:4px 15px}.progress-row{display:flex;align-items:center;gap:10px;padding:12px 0}.progress-row strong{width:77px}.bar{height:4px;flex:1;overflow:hidden}.bar i{height:100%;display:block}.progress-row>small{width:25px;text-align:right}.tip{display:flex;align-items:center;gap:10px;padding:13px 14px;margin-top:16px}.tip img{height:42px;width:33px;object-fit:contain}.study-shelf{margin-top:29px}.shelf-row{display:flex;align-items:center;gap:15px;padding:15px 0}.shelf-row img{width:44px;height:44px;object-fit:contain}.shelf-row strong{display:block}.shelf-row p{margin:4px 0 0}.library-intro{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:18px 22px;margin-bottom:21px}.library-intro h2{margin:0}.library-intro p{margin:6px 0 0}.library-intro img{width:80px;height:65px;object-fit:contain}.filter-row{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-bottom:22px}.filter-search{margin-left:auto;min-width:180px;flex:1;max-width:250px}.filter-search input{width:100%;padding:8px 11px}.result-count{margin-bottom:11px}.library-list{overflow:hidden}.resource-row{display:flex;align-items:center;gap:16px;padding:16px 18px}.row-number{width:22px;flex:none}.row-cover{width:34px;height:46px;object-fit:cover}.row-info{flex:1;min-width:0}.row-info strong{display:block}.row-info small{display:block;margin-top:5px}.empty-state{padding:50px 20px;text-align:center}.empty-state img{width:90px;height:85px;object-fit:contain;margin:0 auto 15px}.empty-state h2{margin:0 0 8px}.empty-state p{margin:0 auto 20px;max-width:370px}.book-grid,.subject-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.book-tile{padding:18px;display:flex;gap:16px;align-items:center}.book-tile img{width:62px;height:85px;object-fit:cover}.book-tile strong{display:block}.book-tile small{display:block;margin-top:7px}.subject-card{padding:22px;transition:background .2s,border-color .2s}.subject-card img{width:65px;height:65px;object-fit:contain;margin-bottom:20px}.subject-card h2{margin:0}.subject-card p{margin:5px 0 23px}.chapter-row{width:100%;text-align:left;display:flex;align-items:center;gap:14px;padding:16px 20px}.chapter-table-label{padding:10px 20px;display:flex;justify-content:space-between}.questions-list .resource-row{align-items:flex-start}.question-preview{max-height:48px;overflow:hidden;margin-bottom:7px}.pagination{display:flex;gap:12px;align-items:center;justify-content:center;margin:22px 0}.reader-content{max-width:none;padding:20px 26px;height:calc(100% - 69px);display:flex;flex-direction:column;gap:15px}.reader-toolbar{display:flex;align-items:center;gap:12px;flex-wrap:wrap}.reader-toolbar strong{flex:1}.pdf-frame{width:100%;flex:1;min-height:600px}.lab-frame{width:100%;height:calc(100dvh - 175px);min-height:630px}.workspace{max-width:1100px}.practice-head{display:flex;gap:10px;align-items:center;margin-bottom:22px}.practice-grid{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(280px,1fr);gap:25px}.question-panel,.answer-panel{padding:25px}.question-panel{min-height:460px}.question-meta{display:flex;justify-content:space-between;gap:10px;margin-bottom:20px}.question-body{overflow-wrap:anywhere}.question-body p{margin:0 0 17px}.question-options{display:grid;gap:9px;margin-top:22px}.option{display:flex;gap:11px;align-items:flex-start;text-align:left;padding:13px}.option b{width:21px;height:21px;display:grid;place-items:center;flex:none}.answer-panel h2{margin:0 0 9px}.answer-input{width:100%;min-height:145px;resize:vertical;padding:12px;margin:12px 0}.answer-solution{margin-top:20px;padding-top:18px;overflow-wrap:anywhere}.answer-solution h3{margin:0 0 12px}.assessment-actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:17px}.practice-footer{display:flex;justify-content:space-between;gap:12px;margin-top:20px}.paper-options{display:flex;gap:12px;align-items:center;flex-wrap:wrap;padding:20px;margin-bottom:20px}.paper-options label{display:grid;gap:6px;flex:1;min-width:120px}.paper-question{padding:21px 22px;display:flex;gap:14px;align-items:start}.paper-question .question-body{flex:1}.paper-summary{display:flex;justify-content:space-between;align-items:center;gap:15px;margin:24px 0}.form-stack{display:grid;gap:17px;padding:25px;max-width:590px}.form-stack label{display:grid;gap:7px}.form-stack input:not([type=checkbox]),.form-stack select{padding:9px 11px;width:100%}.form-stack .check-label{display:flex;align-items:center;gap:9px}.form-stack .check-label input{width:16px;height:16px}.helper-shell{max-width:650px;margin:20px auto}.helper-header{text-align:center;margin:0 auto 30px}.helper-header img{height:120px;width:100px;object-fit:contain;margin:0 auto 17px}.helper-header h2{margin:0}.helper-header p{margin:10px auto;max-width:380px}.helper-form{display:flex;gap:9px;margin-bottom:24px}.helper-form input{flex:1;min-width:0;padding:13px 16px}.prompt-chips{display:flex;justify-content:center;gap:7px;flex-wrap:wrap}.helper-result{margin-top:25px}.activity-grid{display:grid;grid-template-columns:repeat(28,1fr);gap:4px;padding:18px}.activity-cell{aspect-ratio:1}.cs-tools{display:grid;grid-template-columns:1fr 1fr;gap:18px}.cs-card{padding:26px;display:flex;flex-direction:column;align-items:flex-start}.cs-card img{height:95px;width:100px;object-fit:contain;margin-bottom:20px}.cs-card h2{margin:0}.cs-card p{margin:10px 0 25px;max-width:260px}.sim-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:15px}.sim-tile{overflow:hidden}.sim-preview{height:130px;display:grid;place-items:center;overflow:hidden}.sim-preview img{width:100%;height:100%;object-fit:cover}.sim-preview .sim-icon{width:82px;height:82px;object-fit:contain}.sim-tile-copy{padding:17px}.sim-tile h2{margin:6px 0}.sim-tile p{min-height:36px;margin:0 0 15px}.notice{padding:12px 15px;margin-bottom:20px}.katex-display{overflow:auto;max-width:100%;padding-bottom:4px}dialog{padding:0;max-width:440px;width:calc(100% - 32px)}dialog .form-stack{padding:26px}dialog h2{margin:0 0 5px}.dialog-actions{display:flex;justify-content:flex-end;gap:9px;margin-top:10px}#toast{position:fixed;left:50%;bottom:26px;transform:translateX(-50%);max-width:calc(100% - 40px);padding:10px 18px;z-index:100;opacity:0;pointer-events:none;transition:opacity .2s}#toast.show{opacity:1}
@media(min-width:1600px){}
@media(max-width:1150px){.book-grid,.subject-grid,.sim-grid{grid-template-columns:repeat(2,1fr)}.practice-grid{grid-template-columns:1fr}.question-panel{min-height:0}}
@media(max-width:767px){.top-avatar{width:26px;height:26px}.progress-list{padding:4px 17px}.progress-row strong{width:90px}.shelf-row{gap:11px}.shelf-row img{width:36px;height:36px}.library-intro{padding:17px 15px;gap:10px}.library-intro img{width:57px;height:57px}.filter-row{gap:7px}.filter-search{max-width:none;flex-basis:100%;margin-top:5px}.resource-row{gap:11px;padding:15px 12px}.row-number{width:17px}.book-grid{grid-template-columns:1fr 1fr;gap:10px}.book-tile{display:block;padding:15px 12px}.book-tile img{width:55px;height:76px;margin-bottom:12px}.subject-grid{grid-template-columns:1fr 1fr;gap:10px}.subject-card{padding:18px 16px}.subject-card img{width:52px;height:52px;margin-bottom:17px}.chapter-row{padding:15px 13px;gap:10px}.chapter-table-label{padding:10px 13px}.question-preview{max-height:57px}.reader-content{padding:17px 15px;height:calc(100% - 58px)}.reader-toolbar{gap:10px}.reader-toolbar strong{flex-basis:60%}.pdf-frame{min-height:calc(100dvh - 190px)}.lab-frame{height:calc(100dvh - 180px);min-height:600px}.practice-grid{gap:16px}.practice-head{flex-wrap:wrap}.question-panel,.answer-panel{padding:19px}.practice-footer{flex-wrap:wrap}.paper-question{padding:18px 13px;gap:10px}.paper-options{padding:16px;gap:12px}.paper-summary{flex-wrap:wrap}.form-stack{padding:19px}.cs-tools{grid-template-columns:1fr}.cs-card{padding:24px}.cs-card img{width:80px;height:78px}.sim-grid{grid-template-columns:1fr}.sim-preview{height:165px}.activity-grid{grid-template-columns:repeat(14,1fr)}.helper-form input{padding:11px}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;scroll-behavior:auto!important;transition:none!important}}.reduce-motion *{animation:none!important;transition:none!important}
@media print{.paper-question{break-inside:avoid}}
.pdf-controls{display:flex;align-items:center;justify-content:center;gap:15px}.pdf-reader{flex:1;min-height:450px;overflow:auto;padding:16px;display:flex;align-items:flex-start;justify-content:center}.pdf-canvas{display:block;max-width:100%;height:auto!important}.pdf-reader .notice{margin-top:30px}.pdf-reader>.sr-only{flex:none}

.search-open{display:none}@media(max-width:767px){}@media(max-width:767px){}

@media(min-width:768px){}
@media(min-width:768px){}