*,:after,:before{box-sizing:border-box;margin:0;padding:0}body,html{background:var(--color-primary-bg);font-family:DM Sans,system-ui,sans-serif;color:var(--color-text);overflow:hidden}#root,body,html{height:100%}#app-shell{display:flex;flex-direction:column;height:100vh;width:100vw}#tab-strip{display:flex;align-items:flex-end;background:var(--color-secondary-bg);padding:9px 9px 0;gap:2px;border-bottom:1px solid var(--border-subtle);min-height:48px;flex-shrink:0;overflow-x:auto;overflow-y:visible;scrollbar-width:none;position:relative;z-index:110;contain:layout style}#tab-strip::-webkit-scrollbar{display:none}#tab-container{display:flex;gap:2px;align-items:flex-end;min-width:0}.tab-item{display:flex;align-items:center;gap:7px;padding:0 10px;height:37px;min-width:140px;max-width:220px;border-radius:8px 8px 0 0;background:var(--color-surface);border:1px solid transparent;border-bottom:none;cursor:pointer;font-size:12px;font-weight:500;color:var(--color-text-muted);flex-shrink:0;position:relative;user-select:none;transition:background .15s,color .15s;contain:layout style paint}.tab-item.active{background:var(--color-primary-bg);border-color:var(--border-subtle);color:var(--color-text);z-index:2}.tab-item.active:after{content:"";position:absolute;bottom:-1px;left:0;right:0;height:1px;background:var(--color-primary-bg)}.tab-item:hover:not(.active){background:var(--color-surface-hover);color:var(--color-text-dim)}.tab-favicon{width:14px;height:14px;border-radius:3px;flex-shrink:0;background:var(--color-surface);object-fit:contain}.tab-label{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:12px}.tab-close{width:18px;height:18px;border-radius:4px;border:none;background:none;color:var(--color-text-muted);cursor:pointer;font-size:16px;line-height:1;display:flex;align-items:center;justify-content:center;transition:background .15s,color .15s;flex-shrink:0;opacity:0}.tab-item.active .tab-close,.tab-item:hover .tab-close{opacity:1}.tab-close:hover{background:rgba(255,77,77,.2);color:#ff4b4b}#new-tab-btn{width:28px;height:28px;border-radius:6px;background:none;border:1px solid transparent;color:var(--color-text-muted);cursor:pointer;font-size:16px;display:flex;align-items:center;justify-content:center;flex-shrink:0;margin-bottom:4px;transition:background .15s,color .15s,border-color .15s}#new-tab-btn:hover{background:var(--color-surface-hover);border-color:var(--border-default);color:var(--color-text)}#omnibar{gap:5px;padding:8px 12px;background:var(--color-primary-bg);border-bottom:1px solid var(--border-subtle);z-index:109;contain:layout style}#omnibar,.omni-btn{display:flex;align-items:center;flex-shrink:0}.omni-btn{width:36px;height:36px;border-radius:8px;background:none;border:none;color:var(--color-text-dim);cursor:pointer;justify-content:center;transition:background .15s,color .15s}.omni-btn:hover{background:var(--color-surface-hover);color:var(--color-text)}.omni-btn:active{transform:scale(.91)}.omni-btn svg{width:17px;height:17px;stroke-width:2.2;pointer-events:none}#omnibar-actions{display:flex;align-items:center;gap:1px;flex-shrink:0}#address-bar-wrap{flex:1;position:relative;display:flex;align-items:center}#course-search-input{width:100%;height:36px;padding:0 42px 0 14px;background:var(--color-surface);border:1px solid var(--border-default);border-radius:20px;color:var(--color-text);font-family:DM Mono,monospace;font-size:12px;letter-spacing:.01em;outline:none;transition:background .18s,border-color .18s,box-shadow .18s}#course-search-input::placeholder{color:var(--color-text-muted);font-family:DM Sans,sans-serif;font-size:12.5px}#course-search-input:hover{background:var(--color-surface-hover);border-color:var(--border-strong)}#course-search-input:focus{background:var(--color-surface-hover);border-color:var(--color-accent-main);box-shadow:0 0 0 3px var(--color-surface-hover)}#bookmark-star-btn{position:absolute;right:10px;background:none;border:none;cursor:pointer;color:var(--color-text-muted);display:flex;align-items:center;padding:4px;transition:color .15s,transform .15s,background .15s;z-index:2;border-radius:5px}#bookmark-star-btn:hover{color:var(--color-text);transform:scale(1.1);background:var(--color-surface-hover)}#bookmark-star-btn.bookmarked{color:#f5c518}#bookmark-star-btn.bookmarked svg{fill:#f5c518}#bookmark-star-btn svg{width:16px;height:16px;stroke-width:2}#suggestions-dropdown{position:absolute;top:calc(100% + 6px);left:0;right:0;background:var(--color-secondary-bg);border:1px solid var(--border-default);border-radius:12px;overflow:hidden;z-index:500;box-shadow:0 12px 32px rgba(0,0,0,.6);display:none}#suggestions-dropdown.visible{display:block}.suggestion-item{display:flex;align-items:center;gap:10px;padding:9px 14px;cursor:pointer;font-size:13px;color:var(--color-text-dim);transition:background 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svg{flex-shrink:0;opacity:.4;width:14px;height:14px}.suggestion-text{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.suggestion-fill{font-size:11px;color:var(--color-text-muted);opacity:.5;flex-shrink:0;padding-left:6px}#content-area{flex:1;position:relative;overflow:hidden;background:var(--color-primary-bg)}#educational-background-canvas{position:absolute;inset:0;width:100%;height:100%;pointer-events:none;z-index:1}#content-viewer{position:absolute;inset:0;z-index:6;background:transparent;pointer-events:none}#content-viewer.active{background:var(--color-primary-bg);pointer-events:auto}iframe{border:none;width:100%;height:100%;display:block;background-color:transparent!important;color-scheme:light}#education-home{position:absolute;inset:0;z-index:5;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:40px 200px;width:100%}.logo-text{font-family:DM 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svg{width:11px;height:11px;stroke-width:2.5;pointer-events:none}#resource-loading-overlay{position:absolute;inset:0;background-color:var(--color-primary-bg);display:none;flex-direction:column;justify-content:center;align-items:center;z-index:10;gap:16px;transition:opacity .2s ease;contain:layout style paint}#resource-loading-overlay.visible{display:flex}.loader-spinner{width:48px;height:48px;border:3px solid var(--border-subtle);border-top-color:var(--color-accent-main);border-radius:50%;animation:spin .7s linear infinite;will-change:transform}#resource-loading-message{color:var(--color-text-dim);font-size:12px;font-weight:500;letter-spacing:.3px}@keyframes spin{to{transform:rotate(1turn)}}.modal{position:fixed;top:50%;left:50%;transform:translate(-50%,-50%);background:var(--color-secondary-bg);padding:24px;border-radius:var(--radius-lg);z-index:300;border:1px solid var(--border-default);width:360px;box-shadow:0 32px 64px rgba(0,0,0,.75);max-height:80vh;overflow-y:auto;contain:layout style}#learning-preferences-modal{width:480px;max-width:90vw}.hidden{display:none!important}.modal-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:18px}.modal-header h2{margin:0;font-weight:700;letter-spacing:2px;color:var(--color-text-muted)}.clear-all-btn,.modal-header h2{font-size:11px;text-transform:uppercase}.clear-all-btn{background:none;border:none;color:#ff4b4b;font-weight:600;cursor:pointer;letter-spacing:1px}.clear-all-btn:hover{opacity:.7}.list-container{max-height:380px;overflow-y:auto;display:flex;flex-direction:column;gap:6px}.list-item{display:flex;justify-content:space-between;align-items:center;padding:11px 14px;background:var(--color-surface);border:1px solid var(--border-subtle);border-radius:var(--radius-md);transition:background .2s,border-color .2s;cursor:pointer;contain:layout style paint}.list-item:hover{background:var(--color-surface-hover);border-color:var(--border-default)}.setting-row{flex-direction:column;align-items:flex-start;gap:5px;cursor:default}.setting-label{font-size:10px;font-weight:700;text-transform:uppercase;color:var(--color-text-muted)}.setting-control{width:100%;background:transparent;border:none;color:var(--color-text);font-size:14px;font-weight:500;outline:none;padding:3px 0;cursor:pointer;appearance:none}.setting-control option{background:var(--color-secondary-bg);color:var(--color-text)}.modal-close-btn{width:100%;margin-top:18px;padding:13px;background:var(--color-text);color:var(--color-primary-bg);border:none;border-radius:var(--radius-md);font-weight:700;font-size:13px;cursor:pointer;transition:opacity .2s}.modal-close-btn:hover{opacity:.88}.secondary-btn{width:100%;margin-top:7px;padding:10px;background:var(--color-surface);color:var(--color-text);border:1px solid 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