body {
      background-image: url('/images/backdust.jpg'); /* POURQUOI L'IMAGE NE MARCHE PAS ??*/
      padding: 15px;
      border: 4px solid darkslategray;
      border-style: dotted;
      font-family: Garamond, serif;
      font-size: 18px;
      }
      
header {
       background: rgba(203, 217, 217, 0.5);
       outline: 4px dotted darkslategray;
      }
      
main {
        color: darkslateblue;
        background: rgba(203, 217, 217, 0.5);
        outline: 4px dotted darkslategray;
      }

footer {
          background: rgba(203, 217, 217, 0.5);
          text-align: center;
          padding: 8px;
          outline: 4px dotted darkslategray;
          
      }
p {
    font-size: 18px;
    }