20. Absolute positioning

.box{    width: 500px;    height: 300px;    border: solid;    margin:50px auto;    position: relative;}.sub-box{    width: 100px;    height: 100px;}.bgc1{    background-color: darkorange;}.bgc2{    background-color: blue;}.bgc3{    background-color: firebrick;}.bgc4{    background-color: aqua;}.bgc5{    background-color: blueviolet;}.po4{    position:absolute;    left: 400px;    top:  200px;}.po5{    position:absolute;   /* left: 400px;*/    top:  200px;}.po2{    position:absolute;    left: 400px;    top:  0px;}.po3{    position: absolute;    left: 200px;    top:  100px;}