@media (max-width: 300px) {
    body.intro header {
      background-image: url("../images/logo_500_123.png") !important;
    }
  }
  @media (min-width: 301px) and (max-width: 600px) {
    body.intro header {
      background-image: url("../images/logo_500_123.png") !important;
      
    }
  }
  @media (min-width: 601px) and (max-width: 768px) {
    body.intro header {
      background-image: url("../images/logo_5300_246.png") !important;
    }
  }
  @media (min-width: 769px) {
    body.intro header {
      background-image: url("../images/logo_5300_246.png") !important;
    }
  }