*{
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
body{
     font-family: Arial, Helvetica, sans-serif;
    background-color: rgb(34, 196, 61);
}
.caja1{
    background-color: rgb(253, 237, 5) ;
    border: 2px solid black;
    height: 200px;
}
.caja2{
    background-color: rgb(184, 2, 77);
    border: 2px solid black;
    height: 200px;
}