:root{--primary-color:#3b82f6;--secondary-color:#1d4ed8;--success-color:#10b981;--warning-color:#f59e0b;--danger-color:#ef4444;--info-color:#3b82f6;--dark-color:#1f2937;--light-color:#f9fafb;--text-color:#374151;--border-color:#e5e7eb;--shadow-sm:0 1px 2px 0 rgba(0, 0, 0, 0.05);--shadow-md:0 4px 6px -1px rgba(0, 0, 0, 0.1);--shadow-lg:0 10px 15px -3px rgba(0, 0, 0, 0.1);--border-radius:0.5rem}.main-content{flex:1;min-height:calc(100vh - 70px);overflow-y:auto;overflow-x:hidden}.container{max-width:1200px;margin:0 auto;padding:2rem;overflow-x:hidden}.welcome-section{background:#fff;padding:2rem;border-radius:var(--border-radius);margin-bottom:2rem;box-shadow:var(--shadow-sm)}.welcome-section h2{margin:0 0 .5rem 0;color:var(--dark-color)}.welcome-section p{margin:0;color:var(--text-color)}.section-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:1.5rem}.section-header h2{margin:0;color:var(--dark-color);display:flex;align-items:center;gap:.5rem}.invitations-section{margin-bottom:2rem}.invitations-badge{background:var(--warning-color);color:#fff;padding:.25rem .75rem;border-radius:50px;font-size:.8rem;font-weight:700;margin-left:1rem;animation:pulse 2s infinite}@keyframes pulse{0%,100%{opacity:1}50%{opacity:.7}}.invitations-list{display:grid;gap:1rem;margin-top:1rem}.loading-state{display:flex;align-items:center;justify-content:center;gap:.75rem;color:#6b7280}.loading-state i{color:var(--primary-color)}.empty-state-small{padding:1.5rem;text-align:center;color:#6b7280;background:#fff;border:1px dashed var(--border-color);border-radius:var(--border-radius)}.empty-state-small i{display:block;font-size:1.5rem;margin-bottom:.5rem;color:var(--border-color)}.error-message{padding:1.5rem;text-align:center;color:var(--danger-color);background:#fff;border:1px solid var(--danger-color);border-radius:var(--border-radius)}.error-message i{display:block;font-size:2rem;margin-bottom:.5rem;color:var(--danger-color)}.error-message p{margin:.5rem 0;color:var(--text-color)}.recent-tests-section{margin-bottom:2rem}.recent-tests-card{background:#fff;border-radius:var(--border-radius);box-shadow:var(--shadow-sm);padding:1.5rem}.recent-tests-list{display:flex;flex-direction:column;gap:1rem}.test-item{display:flex;align-items:center;justify-content:space-between;gap:1.5rem;padding:1.25rem;background:var(--light-color);border-radius:var(--border-radius);border:1px solid var(--border-color);transition:all .3s ease}.test-item:hover{border-color:var(--primary-color);box-shadow:var(--shadow-sm);transform:translateY(-2px)}.test-info h4{margin:0 0 .35rem 0;color:var(--dark-color);font-size:1.05rem}.test-class{margin:0 0 .75rem 0;color:#6b7280;font-size:.95rem}.test-meta{display:flex;gap:1rem;flex-wrap:wrap;color:#6b7280;font-size:.9rem}.test-meta span{display:inline-flex;align-items:center;gap:.35rem}.test-meta i{color:var(--primary-color)}.btn-sm{padding:.5rem 1rem;font-size:.95rem;border-radius:999px;min-height:40px}.classes-section{margin-bottom:2rem}.classes-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:1.5rem}.class-card{background:#fff;border-radius:var(--border-radius);box-shadow:var(--shadow-md);overflow:hidden;transition:transform .3s ease,box-shadow .3s ease;cursor:pointer}.class-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}.class-card-header{background:var(--info-color);color:#fff;padding:1.5rem;position:relative}.class-card-header h3{margin:0 0 .5rem 0}.class-code{font-size:.875rem;opacity:.9;font-family:monospace}.class-card-body{padding:1.5rem}.class-card-body p{margin:.5rem 0;display:flex;align-items:center;gap:.5rem;color:var(--text-color)}.class-stats{display:flex;justify-content:space-between;margin-top:1rem;padding-top:1rem;border-top:1px solid var(--border-color)}.class-stats span{font-size:.875rem;color:var(--text-color);display:flex;align-items:center;gap:.25rem}.empty-state{text-align:center;padding:3rem;color:var(--text-color)}.empty-state i{font-size:3rem;color:var(--border-color);margin-bottom:1rem}.empty-state h3{margin:1rem 0;color:var(--dark-color)}.loading-spinner{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:3rem 2rem;color:var(--text-color);grid-column:1/-1;gap:1rem}.loading-spinner i{font-size:2rem;color:var(--primary-color)}.loading-spinner p{margin:0;font-size:1rem}.btn{padding:.75rem 1.5rem;border:none;border-radius:var(--border-radius);font-size:1rem;cursor:pointer;display:inline-flex;align-items:center;gap:.5rem;transition:all .3s ease;text-decoration:none;min-height:44px;justify-content:center;line-height:1.4;font-weight:500}.btn-primary{background-color:var(--primary-color);color:#fff}.btn-primary:hover{background-color:var(--secondary-color)}.btn-secondary{background-color:var(--light-color);color:var(--primary-color);border:2px solid var(--primary-color)}.btn-secondary:hover{background-color:var(--primary-color);color:#fff}.btn-block{width:100%}.see-all-link{color:var(--primary-color);text-decoration:none;font-weight:500;font-size:.95rem;display:inline-flex;align-items:center;gap:.25rem;transition:all .2s ease;padding:.5rem 1rem;border-radius:var(--border-radius)}.see-all-link:hover{background-color:var(--light-color);text-decoration:underline}.tests-actions{margin-top:1.5rem;padding-top:1.5rem;border-top:1px solid var(--border-color)}.modal{display:none;position:fixed;z-index:1000;left:0;top:0;width:100%;height:100%;background-color:rgba(0,0,0,.6);backdrop-filter:blur(4px)}.modal-content{background-color:#fff;margin:8% auto;padding:2rem;border-radius:12px;max-width:520px;width:90%;position:relative;box-shadow:0 20px 60px rgba(0,0,0,.3)}.close-modal{position:absolute;right:1rem;top:1rem;padding:.5rem 1rem;border:1px solid var(--border-color);background:#fff;color:var(--text-color);border-radius:var(--border-radius);cursor:pointer;font-size:.9rem;font-weight:500;transition:all .2s ease}.close-modal:hover{background:var(--light-color);border-color:var(--text-color)}.modal-content h2{margin:0 0 1rem 0;color:var(--dark-color);font-size:1.5rem;font-weight:600;padding-right:8rem}.modal-content p{margin:0 0 1.5rem 0;color:var(--text-color);line-height:1.6}.add-class-form{display:flex;gap:1rem;margin-top:1rem;justify-content:center}.class-code-inputs{display:flex;align-items:center;gap:.5rem;justify-content:center}.class-code-single{width:100%;max-width:420px}.class-code-text-input{flex:1 1 auto;min-width:0;height:52px;padding:0 1rem;border:2px solid var(--border-color);border-radius:var(--border-radius);font-size:1.15rem;font-weight:700;letter-spacing:0;text-align:center;text-transform:uppercase;transition:all .2s ease}.class-code-text-input:focus{outline:0;border-color:#3b82f6;box-shadow:0 0 0 3px rgba(59,130,246,.16)}.code-input{width:50px;height:60px;padding:0;border:2px solid var(--border-color);border-radius:var(--border-radius);font-size:1.5rem;font-weight:600;text-align:center;text-transform:uppercase;transition:all .2s ease}.code-input:focus{outline:0;border-color:var(--primary-color);box-shadow:0 0 0 3px rgba(79,70,229,.1);transform:scale(1.05)}.code-separator{font-size:1.5rem;font-weight:600;color:var(--text-color);margin:0 .25rem}.message-box{padding:1rem;border-radius:var(--border-radius);margin-top:1rem;display:flex;align-items:center;gap:.5rem}.message-box.success{background-color:#d1fae5;color:#065f46;border:1px solid #6ee7b7}.message-box.error{background-color:#fee2e2;color:#991b1b;border:1px solid #fca5a5}.message-box.warning{background-color:#fed7aa;color:#92400e;border:1px solid #fdba74}.message-box.info{background-color:#dbeafe;color:#1e40af;border:1px solid #93c5fd}@media (max-width:768px){.container{padding:1rem}.classes-grid{grid-template-columns:1fr;gap:1rem}.class-card{margin-bottom:.5rem;border-radius:12px;box-shadow:var(--shadow-sm);transition:all .2s ease}.class-card:active{transform:scale(.98);box-shadow:var(--shadow-md)}.class-card-header{padding:1.25rem}.class-card-header h3{font-size:1.1rem;margin:0 0 .5rem 0;line-height:1.3}.class-code{font-size:.8rem}.class-card-body{padding:1rem 1.25rem}.class-card-body p{font-size:.9rem;margin:.75rem 0}.class-stats{flex-direction:column;gap:.5rem;align-items:flex-start;margin-top:1rem;padding-top:1rem}.class-stats span{font-size:.85rem}.section-header{flex-direction:column;gap:1rem;align-items:stretch}.section-header h2{font-size:1.25rem;text-align:center}.section-header .btn{min-height:48px;padding:1rem 1.5rem;font-size:1.1rem}.welcome-section{padding:1.5rem;text-align:center;margin-bottom:1.5rem}.welcome-section h2{font-size:1.4rem;margin-bottom:.75rem}.welcome-section p{font-size:1rem;line-height:1.5}.empty-state{padding:2rem 1rem}.empty-state i{font-size:2.5rem}.empty-state h3{font-size:1.25rem;margin:1rem 0 .75rem 0}.empty-state p{font-size:1rem;line-height:1.5}.add-class-form{flex-direction:column;gap:1rem}.class-code-inputs{gap:.4rem}.class-code-single{max-width:none}.class-code-single .btn{height:52px;padding-left:.9rem;padding-right:.9rem}.code-input{width:45px;height:55px;font-size:1.3rem}.code-separator{font-size:1.3rem;margin:0 .15rem}.modal-content{margin:5% auto;width:95%;padding:1.5rem}.invitations-badge{margin-left:.5rem}}