html{
    background-color: honeydew;
}
body{
    margin: auto;
    width: 800px;
    background-color: blueviolet;
}
header, footer{
    height:50px;
}
main{
    display:flow-root;
}
main > div{
    float:left;
}
.izd{
    background-color: brown;
    height: 300px;
    width: 296px;
    border: 2px solid black;
}
.dch{
    background-color: forestgreen;
    height: 300px;
    width: 496px;
    border: 2px solid black;
}