.login {background-color: black;}

.aaa {background-color: lightblue; width:600px; height: 50px; position: relative; padding-bottom: 0;}
.bbb {background-color: gray; width:600px; height: 50px; position: relative; padding-bottom: 0;}
.ccc {background-color: green; width:600px; height: 50px; position: relative; padding-bottom: 0;}


.aleft {background-color: lightgoldenrodyellow; width: 50%; top: 0; left: 0; position: absolute;}
.aright {background-color: lightpink; width: 50%; top: 0; left: 300; position: absolute;}
.bleft {background-color: yellow; width: 50%; top: 0; left: 0; position: absolute;}
.bright {background-color: yellowgreen; width: 50%; top: 0; left: 300; position: absolute;}
.cleft {background-color: cadetblue; width: 50%; top: 0; left: 0; position: absolute;}
.cright {background-color: lightgreen; width: 50%; top: 0; left: 300; position: absolute;}