{box-sizing: border-box;}
body{font-family: Arial, sans-serif;
margin: 10px;
      float: none;
      width: 98%;
  }
header{
       background: rgb(204,204,255);
      /*padding: 30px;*/
        text-align: center;
        font-size: 35px;
        color: rgb(255,255,204);
        width: 100%;
      float: left;
        }
section {
      float: left;
        width: 100%;
         background-color: rgb(204,204,204);
  }
 nav{
      float: left;
      width: 25%;
       height: 300px;
       background: rgb(204,153,255);
       padding: 20px 1%;
       }
       
 nav ul{
        list-style-type: none;
        padding: 0;
        }
        
 article{
         float: left;
         padding: 20px 1%;
         width: 68%;
         background-color: rgb(204,204,204);
         height: 300px;
         }
         
 section::after{
         content:"";
         display: table;
         clear: both;
         }     
         
   footer{
         background-color: rgb(204,153,255);
         text-align: center;
         color: rgb(255,255,255);
        width: 100%;
      float: left;
         }
         
   @media(max-width:600px){
     nav,article{width: 100%;height: auto;}
     }