.rij{
   position:relative;
   left:0;
   top:0; 
   padding: 0;
   margin:  0;
   background-color: #ffffff;
   width: 100%;
   box-sizing: border-box;
  z-index:1;
}
.artikel {
  position:relative;
  left: 0;
  top: 0;
  float: left;
  background-color: #ffffff;
  color:#000000;
  font-size: 12px;
  padding: 12px;
  margin: 0px;
  border: 0px solid #ffffff;
  width: 25%;
  box-sizing: border-box;
}
.artikel >center>  table {
	background:#ffffff;
	}


@media only screen and (max-width: 1000px)  {
.rij{
   width:100%;
}
.artikel {
   width: 50%;
   }
}

@media only screen and (max-width: 640px) {
.rij{
   width:100%;
}
.artikel {
     width: 100%
     }
}