body{
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
}

#header{position: fixed; top: 0; left: 0;}
#footer{position: fixed; bottom: 0; left: 0;}
#main_container{
  position: relative;
  min-height: 600px;
  color: #fff;
}
#main_container > div{
  position: absolute;
  top: 48%; left: 50%;
  transform: translate(-50%,-50%);
}
@media(max-width:1930px){
  #main_container > div{top: 46%;}
  #main_container img{max-width: 360px;}
  #main_container p{font-size: 2.4rem !important;}
}
@media(max-width:767.98px){
  #main_container img{max-width: 350px;}
}
@media(max-width:575.98px){
  #main_container img{max-width: 280px;}
}