@media (min--moz-device-pixel-ratio: 1.3),
  (-o-min-device-pixel-ratio: 2.6/2),
  (-webkit-min-device-pixel-ratio: 1.3),
  (min-device-pixel-ratio: 1.3),
  (min-resolution: 1.3dppx) {
    .header-logo img:not(:first-child) { 
       display: block;    
       margin: 0 auto;
       max-height: 70px; }
    .header-logo img:first-child { display: none; }
  }