header h1{
    text-align: center;
}
a:link{
    color: green;
}
a:visited{
    color: gray;
}
a:active{
    color: red;
}
a:hover{
    color: black;
}
nav ul{
    list-style-type: none;
    margin: 0;
    padding: 0;
}
.content{
    font-size: 35px;
    font-family: Times New Roman;
    color: yellow;
}
body{
    background-color: purple;
}
footer{
    background-color: yellow;
    font-size: 20px;
}
#thumbnail{
    height: 150px;
    width: 200px;
}