.c1{
    width: 800px;
    height: 500px;
    background-color: black;
    color: white;
}

.blackDiv{
width: 300px;
height: 400px;
background-color: black;
color: aliceblue;

}

#content{
width: 500px;
height: 600px;
background-color: black;
color: red;

}