body {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 20px;
}

.quiz-container {
    background-color: #fff;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    width: 100%;
    max-width: 600px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.quiz-header {
    padding: 2rem;
}

.quiz-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
    color: #666;
    flex-wrap: wrap;
    gap: 10px;
}

.quiz-info > div {
    background: #f8f9fa;
    padding: 8px 12px;
    border-radius: 20px;
    font-weight: 500;
}

#timer {
    font-weight: bold;
    color: #28a745;
}

#progress {
    font-weight: bold;
    color: #007bff;
}

#score-display {
    font-weight: bold;
    color: #ffc107;
}

.subtitle {
    text-align: center;
    color: #6c757d;
    margin-bottom: 2rem;
    font-size: 1.1rem;
}

h2 {
    text-align: center;
    margin: 0 0 1.5rem 0;
    color: #333;
    font-size: 1.8rem;
}

.setup-options {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.option-group {
    display: flex;
    flex-direction: column;
}

.option-group label {
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #495057;
}

.option-group select {
    padding: 12px;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 1rem;
    background-color: #fff;
    transition: border-color 0.3s;
}

.option-group select:focus {
    outline: none;
    border-color: #8e44ad;
    box-shadow: 0 0 0 3px rgba(142, 68, 173, 0.1);
}

.start-btn, .action-btn, .secondary-btn {
    padding: 15px;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 10px 0;
    width: 100%;
}

.start-btn, .action-btn {
    background: linear-gradient(135deg, #8e44ad, #9b59b6);
    color: white;
}

.start-btn:hover, .action-btn:hover {
    background: linear-gradient(135deg, #732d91, #8e44ad);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(142, 68, 173, 0.4);
}

.start-btn:focus, .action-btn:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(142, 68, 173, 0.4);
}

.secondary-btn {
    background: #f8f9fa;
    color: #495057;
    border: 2px solid #e9ecef;
}

.secondary-btn:hover {
    background: #e9ecef;
    transform: translateY(-2px);
}

ul {
    list-style-type: none;
    padding: 0;
}

ul li {
    font-size: 1.1rem;
    margin: 1rem 0;
    padding: 15px;
    border-radius: 8px;
    background: #f8f9fa;
    transition: all 0.3s ease;
    cursor: pointer;
    display: flex;
    align-items: center;
}

ul li:hover {
    background: #e9ecef;
    transform: translateX(5px);
}

ul li input[type="radio"] {
    margin-right: 15px;
    transform: scale(1.3);
}

/* Added styles for the selected state of a list item */
ul li.selected {
    background: #e0f2f1;
    border: 2px solid #00796b;
    color: #004d40;
    transform: scale(0.98);
}


.answers-list {
    margin: 2rem 0;
}

.answers-list.hidden {
    display: none;
}

.tf-btn {
    padding: 15px;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 10px;
    flex: 1;
}

.tf-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.tf-btn[data-answer="true"] {
    background: linear-gradient(135deg, #28a745, #218838);
    color: white;
}

.tf-btn[data-answer="false"] {
    background: linear-gradient(135deg, #dc3545, #c82333);
    color: white;
}

.tf-btn.selected {
    transform: scale(0.95);
    box-shadow: 0 0 0 3px rgba(40, 167, 69, 0.5) inset;
}

.feedback {
    padding: 15px;
    border-radius: 8px;
    margin: 20px 0;
    text-align: center;
    font-weight: 600;
    transition: all 0.3s ease;
}

.feedback.correct {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.feedback.incorrect {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.feedback.error {
    background-color: #fff3cd;
    color: #856404;
    border: 1px solid #ffeaa7;
}

.feedback.hidden {
    display: none;
}

.loading {
    text-align: center;
    padding: 2rem;
}

.spinner {
    border: 4px solid rgba(0, 0, 0, 0.1);
    border-left-color: #8e44ad;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.loading p {
    margin: 0;
    color: #6c757d;
    font-weight: 500;
}

.loading.hidden {
    display: none;
}

.hidden {
    display: none !important;
}

.question-meta {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.meta-tag {
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.difficulty-easy {
    background-color: #d4edda;
    color: #155724;
}

.difficulty-medium {
    background-color: #fff3cd;
    color: #856404;
}

.difficulty-hard {
    background-color: #f8d7da;
    color: #721c24;
}

.results {
    text-align: center;
    padding: 1rem;
}

.score-circle {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background: conic-gradient(#8e44ad 70%, #f8f9fa 0%);
    margin: 0 auto 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.score-text {
    width: 130px;
    height: 130px;
    border-radius: 50%;
    background: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: bold;
    color: #8e44ad;
}

.results-details p {
    font-size: 1.1rem;
    margin: 1rem 0;
}

.results-details strong {
    color: #8e44ad;
}

.results-actions {
    margin-top: 2rem;
}

.error-message {
    background-color: #dc3545;
    color: white;
    padding: 1rem;
    margin: 1rem 0;
    border-radius: 8px;
    text-align: center;
    font-weight: bold;
    animation: shake 0.5s ease-in-out;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

@media (max-width: 600px) {
    .quiz-header {
        padding: 1.5rem;
    }
    
    .quiz-info {
        flex-direction: column;
        gap: 5px;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    .setup-options {
        gap: 1rem;
    }
    
    ul li {
        padding: 12px;
        font-size: 1rem;
    }
    
    .tf-btn {
        padding: 12px;
        font-size: 1rem;
    }
}