.imgBack{
  position: absolute;
  width: 100%;
  height: calc(35% + 8px);
  top: 0;
  left: 0;
} 

@media (min-width: 768px) {
  .imgBack{
    position: absolute;
    width: 100%;
    height: calc(100% + 8px);
    top: 0;
    left: 0;
  } 
}

.header{
  padding: 30px 0;
} 

@media (min-width: 768px) {
  .header{
    position: relative;
    display: inline-block;
    width: 100%;
    padding: 50px 0px;
    box-sizing: border-box;
  } 
}

.top{
  padding-top: 18%;
} 

@media (min-width: 768px) {
  .top{
    padding-top: 3%;
  } 
}