header {
        margin-top: 35px;
        margin-left: 100px;
       }
       
dt.title {
          font-size: 50px;
          font-weight: bold;
          color: Blue;
          text-shadow: -5px 5px 10px Gray;
         }
         
dt.title+dd {
             font-size: 30px;
             font-weight: bold;
             color: Black;
             text-shadow: -5px 5px 10px Gray;
            }
            
#menu {
       border-radius: 25px;
       margin: 25px 100px;
       width: 900px;
       background-color: #f1f1f1;
      }
      
iframe {
        border: none;
        margin-left: 100px;
        width: 500px;
        padding: 10px;
       }
       
article {
         border: none;
         margin-left: 50px;
         width: 900px;
        }
        
div.double {
            border-style: double;
            margin-left: 50px;
            width: 500px;
            padding:10px;
           }