#welcome {
  background: url('../img/boykott_v1.png') no-repeat 50%;
  /*-webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;*/
  background-size: contain;
  width: 100%;
  height: 100%;
  min-height: 640px; 
  /*min-height: 891px;*/ 
}