/* Non-essential Styles */
h2  { clear:both; }
div { background-color:gold; padding:3px 0;   }
hr  { clear:both; border:0; padding-top:20px; }


/* Essential Styles */
body  { max-width:1200px; }
div   { min-width:100px;  }

*.ex1 { float:left; width:50%;                     }
*.ex2 { float:left; width:50%;   border:1px solid; }
*.ex3 { float:left; width:45%;   margin-left:5%;   }
*.ex4 { float:left; width:49.5%; margin-left:5px;  }