.about-section{
  background-repeat:no-repeat;
  background-size:cover;
}
@media screen and (max-width:640px){
 .about-section.hero-sec{margin-top:90px !important;background-position: 50% 31% !important;}
}
@media screen and (max-width:450px){
  .about-section.hero-sec{background-position: 42% 31% !important;}
}
}