@media only screen and (min-width: 680px) {
  #cover img{
    height: 80vh;
    object-fit: cover;
    object-position: bottom;
    position: relative;
    z-index: 3;
  }
}

#mainContent{
  display: flex;
  justify-content: center;
  margin-bottom: 120px;
  margin: 50px 0;
}

@media only screen and (min-width: 680px) {
  #mainContent{
    margin: -10vh 0 100px 0;
    position: relative;
    z-index: 5;
  }
}