.cube{
    background-color:blue;
    height:10%;
    width:10%;
    position:absolute;
    top: 10%;
    left:10%;
    border-radius: 5px;


}
.container{
    background-color: greenyellow;
    width:500px;
    height:500px;
    position: relative;
    border: 3px solid green;
    margin: 20px auto;
    border-radius: 10px;
    background-image: url();

}