:root{--primary: #5B4FE8;--primary-light: #7B72ED;--primary-dark: #3D33C4;--cta: #FF6B4A;--cta-light: #FF8A6E;--success: #2ECC71;--error: #EF4444;--warning: #F59E0B;--streak: #FF9F1C;--focus: #00B4D8;--math: #4A90E2;--physics: #F5A623;--chemistry: #2ECC71;--biology: #E84393;--arts: #9B59B6;--bg-dark: #14132A;--bg-card: #1E1D38;--bg-sidebar: #0F0E20;--text-primary: #F1F0FF;--text-secondary: #9F9EC4;--border: rgba(123, 114, 237, .14);--border-focus: rgba(91, 79, 232, .6);--radius-sm: 8px;--radius-md: 14px;--radius-lg: 20px;--shadow-card: 0 10px 30px rgba(10, 9, 25, .6);--transition: all .22s cubic-bezier(.4, 0, .2, 1)}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-dark);color:var(--text-primary);font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;line-height:1.5;overflow-x:hidden}::-webkit-scrollbar{width:8px;height:8px}::-webkit-scrollbar-track{background:var(--bg-dark)}::-webkit-scrollbar-thumb{background:#ffffff1a;border-radius:var(--radius-sm)}::-webkit-scrollbar-thumb:hover{background:var(--primary)}a{color:var(--primary-light);text-decoration:none;transition:var(--transition)}a:hover{color:var(--primary)}.app-container{display:flex;min-height:100vh;background-color:var(--bg-dark)}.main-content{flex:1;display:flex;flex-direction:column;min-width:0;height:100vh;overflow-y:auto}.page-container{padding:2rem;max-width:1400px;width:100%;margin:0 auto}.sidebar{width:260px;background-color:var(--bg-sidebar);border-right:1px solid var(--border);display:flex;flex-direction:column;height:100vh;position:sticky;top:0;z-index:100;transition:var(--transition)}.sidebar.collapsed{width:76px}.sidebar-logo{padding:1.5rem 1.25rem;font-size:1.25rem;font-weight:700;color:var(--text-primary);display:flex;align-items:center;gap:.75rem;border-bottom:1px solid var(--border);cursor:pointer}.sidebar-logo-icon{color:var(--primary);flex-shrink:0}.sidebar-logo-text{white-space:nowrap;opacity:1;transition:opacity .2s ease}.sidebar.collapsed .sidebar-logo-text{opacity:0;width:0;overflow:hidden}.sidebar-nav{padding:1rem .75rem;display:flex;flex-direction:column;gap:.5rem;flex:1}.sidebar-item{display:flex;align-items:center;gap:.75rem;padding:.75rem 1rem;border-radius:var(--radius-sm);color:var(--text-secondary);font-weight:500;font-size:.95rem;transition:var(--transition);cursor:pointer;border:none;background:none;text-align:left;width:100%}.sidebar-item:hover{color:var(--text-primary);background-color:#ffffff0d}.sidebar-item.active{background:linear-gradient(135deg,#5b4fe8,#7b72ed);color:#fff;box-shadow:0 4px 16px #5b4fe866}.sidebar-item-icon{flex-shrink:0}.sidebar-item-text{white-space:nowrap;opacity:1;transition:opacity .2s ease}.sidebar.collapsed .sidebar-item-text{opacity:0;width:0;overflow:hidden}.sidebar-collapse-toggle{margin-top:auto;border-top:1px solid var(--border);padding:1rem;display:flex;align-items:center;justify-content:center;color:var(--text-secondary);background:none;border-left:none;border-right:none;border-bottom:none;cursor:pointer;transition:var(--transition)}.sidebar-collapse-toggle:hover{color:var(--text-primary);background-color:#ffffff05}.topbar{height:70px;background-color:var(--bg-sidebar);border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;padding:0 2rem;position:sticky;top:0;z-index:90}.topbar-left{display:flex;align-items:center;gap:1rem}.topbar-right{display:flex;align-items:center;gap:1.5rem}.topbar-user{display:flex;align-items:center;gap:.75rem}.topbar-user-avatar{width:36px;height:36px;border-radius:50%;background-color:var(--primary);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:600;font-size:.95rem}.topbar-user-info{display:flex;flex-direction:column}.topbar-username{font-size:.9rem;font-weight:600;color:var(--text-primary)}.topbar-user-role{font-size:.75rem;color:var(--text-secondary)}.logout-btn{background:none;border:none;color:var(--text-secondary);cursor:pointer;padding:.5rem;border-radius:var(--radius-sm);display:flex;align-items:center;justify-content:center;transition:var(--transition)}.logout-btn:hover{color:var(--error);background-color:#e74c3c1a}.card{background-color:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius-md);padding:1.5rem;box-shadow:var(--shadow-card);transition:var(--transition)}.card:hover{border-color:#ffffff1f}.stat-card{display:flex;flex-direction:column;gap:.75rem}.stat-card-header{display:flex;align-items:center;justify-content:space-between;color:var(--text-secondary)}.stat-card-title{font-size:.875rem;font-weight:500}.stat-card-icon{color:var(--primary-light);display:flex;align-items:center;justify-content:center}.stat-card-value{font-size:1.8rem;font-weight:700;color:var(--text-primary);letter-spacing:-.02em}.stat-card-footer{display:flex;align-items:center;gap:.5rem;font-size:.8rem}.stat-card-trend{display:flex;align-items:center;font-weight:600}.stat-card-trend.up{color:var(--success)}.stat-card-trend.down{color:var(--error)}.stat-card-trend-text{color:var(--text-secondary)}.form-group{margin-bottom:1.25rem;display:flex;flex-direction:column;gap:.5rem}.form-label{font-size:.875rem;font-weight:500;color:var(--text-secondary)}.form-input,.form-select,.form-textarea{background-color:#ffffff08;border:1px 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transparent;cursor:pointer;transition:var(--transition);text-decoration:none;white-space:nowrap}.btn-primary{background:linear-gradient(135deg,#5b4fe8,#7b72ed);color:#fff;box-shadow:0 4px 14px #5b4fe859}.btn-primary:hover{background:linear-gradient(135deg,#6c5ce7,#8b7cf7);transform:translateY(-2px);box-shadow:0 6px 20px #5b4fe880}.btn-primary:active{transform:translateY(0)}.btn-secondary{background-color:#ffffff14;border-color:var(--border);color:var(--text-primary)}.btn-secondary:hover{background-color:#ffffff26}.btn-danger{background-color:var(--error);color:#fff}.btn-danger:hover{background-color:#ff5c4c}.btn-cta{background-color:var(--cta);color:#fff}.btn-cta:hover{background-color:#ff8163}.btn:disabled{opacity:.5;cursor:not-allowed;transform:none!important}.badge{display:inline-flex;align-items:center;gap:.25rem;padding:.25rem .5rem;border-radius:var(--radius-sm);font-size:.75rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em}.table-container{overflow-x:auto;border:1px solid var(--border);border-radius:var(--radius-md);background-color:var(--bg-card);margin-top:1rem}.table{width:100%;border-collapse:collapse;text-align:left}.table th{background-color:#ffffff05;color:var(--text-secondary);font-weight:600;font-size:.8rem;text-transform:uppercase;letter-spacing:.05em;padding:1rem 1.5rem;border-bottom:1px solid var(--border);cursor:pointer;-webkit-user-select:none;user-select:none}.table th:hover{color:var(--text-primary)}.table td{padding:1rem 1.5rem;border-bottom:1px solid var(--border);font-size:.9rem;color:var(--text-primary);vertical-align:middle}.table tr:last-child td{border-bottom:none}.table tr:hover td{background-color:#ffffff03}.pagination{display:flex;justify-content:space-between;align-items:center;padding:1rem 1.5rem;border-top:1px solid var(--border);background-color:#ffffff03}.pagination-info{font-size:.875rem;color:var(--text-secondary)}.pagination-buttons{display:flex;gap:.5rem}.dashboard-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:1.5rem;margin-bottom:2rem}.chart-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(500px,1fr));gap:1.5rem;margin-bottom:2rem}@media (max-width: 768px){.chart-grid{grid-template-columns:1fr}.page-container{padding:1rem}.sidebar{position:fixed;height:100vh;left:-260px}.sidebar.mobile-open{left:0}}.loading-spinner{display:inline-block;width:2rem;height:2rem;border:3px solid rgba(255,255,255,.1);border-radius:50%;border-top-color:var(--primary);animation:spin 1s ease-in-out infinite}@keyframes spin{to{transform:rotate(360deg)}}.loading-container{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:400px;gap:1rem;color:var(--text-secondary)}.filter-bar{display:flex;gap:1rem;margin-bottom:1.5rem;flex-wrap:wrap;align-items:center}.filter-input{flex:1;min-width:200px}.filter-select{min-width:150px;width:auto}.tree-node{border-left:2px solid var(--border);padding-left:1.25rem;margin-left:.75rem;margin-top:.5rem}.tree-header{display:flex;align-items:center;justify-content:space-between;padding:.75rem;background:#ffffff05;border:1px solid var(--border);border-radius:var(--radius-sm);cursor:pointer;-webkit-user-select:none;user-select:none;transition:var(--transition)}.tree-header:hover{background:#ffffff0a}.tree-actions{display:flex;gap:.5rem}.page-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:2rem;gap:1rem;flex-wrap:wrap}.page-title{font-size:1.8rem;font-weight:700;letter-spacing:-.02em}.page-subtitle{font-size:.95rem;color:var(--text-secondary);margin-top:.25rem}.sidebar-toggle{display:none;background:none;border:none;color:#fff;cursor:pointer;font-size:1.5rem}@media (max-width: 1024px){.sidebar-toggle{display:block}}.subject-svg-icon svg,.subject-svg-preview svg{width:100%;height:100%;max-width:100%;max-height:100%;display:block}