@media (max-width: 600px) { 
  .warnx {  width: 25em; } 
  body{
  background-color: #E6E6FA !important;
  }
}

 @media (min-width: 601px) { 
.warnx { width: 50em;}

body {
  background: url('https://poczta.sum.edu.pl/skins/outlook/assets/images/bg_post.png') center no-repeat !important;
}

}

@media (max-width: 600px) {
  .warnx {  width: 25em; }
  body{
  background-color: #E6E6FA !important;
  }
}

 @media (min-width: 601px) {
.warnx { width: 50em;}

body {
  background: url('https://poczta.sum.edu.pl/skins/outlook/assets/images/bg_post.png') center no-repeat !important;
}

}