body {
    font-family: 'Roboto', sans-serif;
    background-color: #f8f9fa;
    margin: 0;
    padding: 0;
}

h1 {
    color: #343a40;
}

.card-header {
    background-color: #007bff;
    color: white;
}

.card-body {
    background-color: #ffffff;
}

h2 {
    color: #ffffff;
}

h3 {
    color: #343a40;
}

.lesson-info {
    font-weight: bold;
    color: #343a40;
}

.correct-answer {
    color: green;
    font-weight: bold;
}