#contactForm #wrapper-vorname {
  float: left;
  width: 50%;

}
#contactForm #wrapper-tel {
  float: left;
  width: 48%;
  margin-right: 2%;
}
@media only screen and (max-width: 480px) {
    /* CSS rules for mobile devices */
    .header-contact{
        font-size: 13px;
    }

  }

@media only screen and (min-width: 481px) and (max-width: 768px) {
    /* CSS rules for tablets */
    .header-contact{
        font-size: 11px;
    }
  }