header {
    background-color: lightgrey;
    color: white;
    text-align: center;
    padding: 20px;
}

section {
    margin: 50px;
    padding: 30px;
}

#section1 {
    background-color: lightgrey;
}

#section3 {
    border: 4px solid black;
}

p {
    color: blue;
}

ul {
    background-color: orange;
}

li {
    background-color: red;
}

footer {
    text-align: center;
    border: 4px solid black;
}

img {
    height: 100px;
    margin: 20px;
}