* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 500px;
}

.screen {
    display: none;
    background: white;
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
}

.screen.active {
    display: block;
    animation: fadeIn 0.3s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Écran de sélection */
#level-selection {
    text-align: center;
}

#level-selection h1 {
    color: #333;
    margin-bottom: 20px;
    font-size: 28px;
}

#level-selection p {
    color: #666;
    margin-bottom: 30px;
    font-size: 18px;
}

.button-group {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.btn {
    padding: 18px 30px;
    border: none;
    border-radius: 12px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

/* Écran de question */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

.btn-back {
    background: #f0f0f0;
    color: #333;
    font-size: 16px;
    padding: 10px 20px;
}

.btn-back:hover {
    background: #e0e0e0;
}

.level-badge {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
}

.question-type {
    color: #666;
    font-size: 14px;
    margin-bottom: 10px;
    text-align: center;
}

.question-text {
    font-size: 48px;
    text-align: center;
    margin: 30px 0;
    min-height: 100px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #333;
}

.question-subtext {
    font-size: 24px;
    color: #666;
    margin-top: 10px;
}

.options {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 20px;
}

.option {
    padding: 20px;
    background: #f8f9fa;
    border: 2px solid transparent;
    border-radius: 12px;
    font-size: 18px;
    cursor: pointer;
    transition: all 0.2s ease;
    text-align: center;
}

.option:hover {
    background: #e9ecef;
    border-color: #667eea;
}

.option.selected {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

.option.correct {
    background: #4caf50;
    color: white;
    border-color: #4caf50;
}

.option.incorrect {
    background: #f44336;
    color: white;
    border-color: #f44336;
}

.option.disabled {
    cursor: not-allowed;
    opacity: 0.6;
}

.feedback {
    margin-top: 20px;
    text-align: center;
    display: none;
}

.feedback.show {
    display: block;
}

.feedback-message {
    font-size: 18px;
    margin-bottom: 15px;
    font-weight: 600;
}

.feedback-message.correct {
    color: #4caf50;
}

.feedback-message.incorrect {
    color: #f44336;
}

.feedback-answer {
    font-size: 16px;
    color: #666;
    margin-bottom: 20px;
}

.btn-next {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    width: 100%;
}

.btn-next:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

/* Responsive */
@media (max-width: 480px) {
    .screen {
        padding: 20px;
    }

    .question-text {
        font-size: 36px;
        min-height: 80px;
    }

    #level-selection h1 {
        font-size: 24px;
    }

    .option {
        font-size: 16px;
        padding: 16px;
    }
}