.hide-header {
opacity: 0;
margin-top: -200px !important;
}
 
.show-header {
opacity: 1;
margin-top: 0px !important;
}
 
#my_custom_header {
-webkit-transition: all 0.5s ease !important;
-moz-transition: all 0.5s ease !important;
-o-transition: all 0.5s ease !important;
-ms-transition: all 0.5s ease !important;
transition: all 0.5s ease !important;
}