/* element selector */
body {
    font-family: Arial, sans-serif;
    background-color: #f5f5f5;
    margin: 20px;
}

#main-title {
    color: darkblue;
    text-align: center;
}

.section {
    color: darkgreen;
    margin-top: 20px;
}

img {
    display: block;
    margin: 10px auto;
}

ul {
    background-color: #ffffff;
    padding: 10px;
    border-radius: 5px;
}