.congress-registration {

   background-image:url("../../images/congress-background.jpeg");

   background-size: cover;

   background-attachment: fixed;

} 



#home-header-course .courseVisual,

#page-header-course .courseVisual {

        background-image: url("../../images/mainVisual-lg.png");

} 



@media screen and (max-width:991px) {

  #home-header-course .courseVisual,

  #page-header-course .courseVisual {

      background-image: url("../../images/mainVisual-sm.png");

    }

}



@media screen and (max-width:767px) {

  #home-header-course .courseVisual,

  #page-header-course .courseVisual {

      background-image: url("../../images/mainVisual-xs.png");

    }

}