#loading{position:fixed;top:0;left:0;width:100vw;height:100vh;background:rgba(255,255,255,0.5);z-index:9999;backdrop-filter:blur(5px);display:none}.loading-content{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);text-align:center;background:white;padding:2rem;border-radius:8px;box-shadow:0 2px 10px rgba(0,0,0,0.1)}.loading-content img{display:block;margin:0 auto;width:64px;height:64px}.loading-text{color:#6c757d;font-size:20px;margin-top:1rem}body{font-family:'Poppins','Segoe UI','Inter',sans-serif}.navbar-custom{background:linear-gradient(90deg,#000 0,#575750 100%)}.navbar-brand{font-weight:600;color:#f8c471!important}.nav-link{color:#fff!important;display:flex;align-items:center}.nav-link i{margin-right:8px}.dropdown-menu{font-size:.95rem}.question-review{padding:15px;border-radius:5px;margin-bottom:20px}.question-review.correct{background-color:rgba(40,167,69,0.1)}.question-review.incorrect{background-color:rgba(220,53,69,0.1)}.option{padding:10px;margin:5px 0;border-radius:4px}.correct-answer{background-color:rgba(40,167,69,0.2);border-left:4px solid #28a745}.explanation{background-color:#f8f9fa;padding:15px;border-radius:4px;margin-top:10px}.question-container.unanswered{border-left:4px solid #dc3545;background-color:rgba(220,53,69,0.1)}.timer-warning{color:#dc3545;animation:blink 1s infinite}@keyframes blink{50%{opacity:.5}}.timer-container{font-size:1.2rem;font-weight:bold}#timer{font-size:1.2rem;padding:8px 12px;border-radius:4px;min-width:80px;display:inline-block;text-align:center}.question-container{background-color:#fff;padding:.3rem;border-radius:8px;box-shadow:0 2px 4px rgba(0,0,0,0.1)}.question-container.unanswered{border-left:4px solid #dc3545}.form-check{margin:10px 0}@keyframes pulse{0%{opacity:1}50%{opacity:.5}100%{opacity:1}}.question-review{padding:20px;border-radius:8px;margin-bottom:20px;background-color:#fff;box-shadow:0 2px 4px rgba(0,0,0,0.1)}.question-review.correct{border-left:4px solid #28a745}.question-review.incorrect{border-left:4px solid #dc3545}.score-summary{font-size:1.2rem;font-weight:bold;color:#495057;margin-top:10px}.options-review{margin:15px 0}.option-item{padding:12px 15px;margin:8px 0;border-radius:6px;background-color:#f8f9fa;border:1px solid #dee2e6;position:relative}.option-content{display:flex;justify-content:space-between;align-items:center}.correct-answer{background-color:rgba(40,167,69,0.1);border-color:#28a745}.incorrect-answer{background-color:rgba(220,53,69,0.1);border-color:#dc3545}.explanation{background-color:#f8f9fa;padding:15px;border-radius:6px;border-left:4px solid #17a2b8}.explanation h6{color:#17a2b8;margin-bottom:10px}.badge{font-size:.8rem;padding:5px 10px}@media(max-width:768px){.option-content{flex-direction:column;align-items:flex-start}.badge{margin-top:5px}}@keyframes fadeIn{from{opacity:0}to{opacity:1}}.badge{animation:fadeIn .5s ease-in}.mode-card{transition:transform .3s ease;border:none;box-shadow:0 4px 6px rgba(0,0,0,0.1)}.mode-card:hover{transform:translateY(-5px)}.mode-icon{height:80px;display:flex;align-items:center;justify-content:center}.mode-features{margin:20px 0}.mode-features ul li{margin:10px 0;font-size:1.1rem}.card-title{color:#2c3e50;font-weight:bold}.lead{color:#6c757d}.progress-indicator{font-size:1.1rem;color:#6c757d}.alert{margin-bottom:1rem;border:none;border-radius:4px;padding:1rem;position:relative}.alert-success{background-color:#d4edda;color:#155724;border-left:4px solid #28a745}.alert-danger{background-color:#f8d7da;color:#721c24;border-left:4px solid #dc3545}.alert-warning{background-color:#fff3cd;color:#856404;border-left:4px solid #ffc107}.alert-info{background-color:#d1ecf1;color:#0c5460;border-left:4px solid #17a2b8}.alert-dismissible{padding-right:4rem}.alert-dismissible .btn-close{position:absolute;top:0;right:0;padding:1.25rem 1rem}.alert.fade.show{animation:slideInDown .5s ease-in-out}@keyframes slideInDown{from{transform:translateY(-100%);opacity:0}to{transform:translateY(0);opacity:1}}.explanation-container{padding:20px;border-radius:8px;margin-top:20px}.explanation-container.correct{background-color:rgba(40,167,69,0.1);border:1px solid #28a745}.explanation-container.incorrect{background-color:rgba(220,53,69,0.1);border:1px solid #dc3545}.explanation-content{background-color:white;padding:15px;border-radius:6px;margin-top:15px}.option-item{padding:10px;border:1px solid #dee2e6;border-radius:6px;transition:all .3s ease}.option-item:hover{background-color:#f8f9fa}.card-deck{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:20px}.card{transition:transform .3s ease;margin:2px}.card:hover{transform:translateY(-1px)}.question-preview{background-color:#fff;border-radius:8px;padding:20px;margin-bottom:20px;box-shadow:0 2px 4px rgba(0,0,0,0.05)}.question-header{border-bottom:2px solid #f0f0f0;padding-bottom:10px}.question-text{font-size:1.1rem;color:#2c3e50;margin:15px 0}.options-list{margin:20px 0}.option-preview{padding:12px 15px;margin:8px 0;border-radius:6px;border:1px solid #dee2e6;transition:all .3s ease;position:relative}.option-preview:hover{background-color:#f8f9fa}.option-content{display:flex;align-items:center;gap:10px}.option-label{font-weight:bold;color:#6c757d;min-width:25px}.option-text{flex-grow:1}.correct-option{background-color:rgba(40,167,69,0.1);border-color:#28a745}.correct-badge{background-color:#28a745;color:white;padding:4px 8px;border-radius:4px;font-size:.85rem;display:inline-flex;align-items:center;gap:5px}.explanation-box{background-color:#f8f9fa;border-radius:6px;padding:15px;margin-top:20px;border-left:4px solid #17a2b8}.explanation-header{color:#17a2b8;margin-bottom:10px;display:flex;align-items:center;gap:8px}.explanation-content{color:#495057;font-size:.95rem;line-height:1.5}.question-divider{border-top:2px dashed #dee2e6;margin:30px 0}@keyframes spin{0%{transform:rotate(0deg)}100%{transform:rotate(360deg)}}#refreshBtn.loading i{animation:spin 1s linear infinite}.difficulty-indicator i{margin-right:3px}.option-item{transition:all .2s}.option-item:hover{background-color:#f8f9fa;border-radius:4px}.explanation-container.correct{border-left:5px solid #28a745}.explanation-container.incorrect{border-left:5px solid #dc3545}.metadata .badge{font-size:.8rem}