.square {
    width: 200px;
    height: 200px;
}
#blockDarkblue{
    background-color: Darkblue;
    float: right
}
#container1{
    background-color: red; 
    margin:  auto;
    width: 400px;
    height: 200px;
}
#container2{
    background color: darkblue;
    margin: 0 auto;
    width: 400px;
    height: 200px;
}
#blockRed{
    background-color: red;
    float: right
}
#container3{
    background-color: darkblue;
    margin: 0 auto;
    width: 200px;
    height: 200px;
}
.sqaure2{
    width: 100px;
    height: 20px;
    top: 0px;
    left: 150px;
    position: relative;
}
.sqaure3{
    width: 100px;
    height: 20px;
    top: -20px;
    left: -250px;
    position: relative;
}