Wie kann ich mit css die zwei div container untereinander mit Abstand dazwischen anzeigen lassen?
<!DOCTYPE html>
<html>
   <head>
      <title></title>
      <style>
         .haupt {
         margint top: 50px;
         }
         .b1 {
         float: left;
         width: 400px;
         padding: 20px 0;
         color: #01DF01;
         border-bottom-width: 3px;
         border-style: solid;
         width: 50;
         height: 30;
         background-color: #fff;
         }
         .b2 {
         float: both;
         width: 400px;
         padding: 20px 0;
         color: #01DF01;
         border-bottom-width: 3px;
         border-style: solid;
         width: 50;
         height: 30;
         background-color: #fff;
         }
      </style>
   </head>
   <body>
      <div class="haupt">
         <div class="b1">
            Lorem ipsum dolor sit amet, consetetur sadipscing elitr,<br>
            sed diam nonumy eirmod tempor invidunt ut labore et<br>
            dolore magna aliquyam erat, sed diam voluptua.<br>
            At vero eos et accusam et justo duo dolores et
         </div>
         <div class="b2">
            Lorem ipsum dolor sit amet, consetetur sadipscing elitr,<br>
            sed diam nonumy eirmod tempor invidunt ut labore et<br>
            dolore magna aliquyam erat, sed diam voluptua.<br>
            At vero eos et accusam et justo duo dolores et
         </div>
      </div>
   </body>
</html>                  
HTML, CSS