form {
  width: 96%;
  max-width:840px;
  padding: 2%;
  border: 1px solid #ddd;
}
fieldset {
  width: 94%;
  /*border: 1px solid #ddd;*/
  margin: auto;
  /*padding: 2%;*/
}
.textfeld, .submitbutton {
  margin: 2%;
}
.textfeld label {
  display: block;
}
.textfeld input, .textfeld textarea {
  width: 100%;
  padding: 4px;
  display: block;
  border-radius: 2px;
  border: 1px solid #999;
}
label {
  cursor: pointer;
}
@media screen and (min-width: 600px) {
  .textfeld input, .submitbutton {
     display: inline-block;
     width: 70%;
   }

  .textfeld label {
     display: inline-block;
     margin: 0 2% 0 0;
     vertical-align: top;
     width: 20%;
  }
}
</style>

<!--Ende Responsives Formular-Styling-->