.header{
  position: fixed;
  z-index: 2;
  background-color: #FFFFFF;
  box-shadow: 0px 0px 5px 0px hsla(0,0%,0%,0.1);
}
.main{
  padding-top: 150px;
}

@media screen and (max-width: 767px){
  .header{
    position: relative;
    box-shadow: 0px 0px 0px 0px hsla(0,0%,0%,0.1);
    padding-top: 0px;
  }
  .main{
    padding-top: 0px;
  }

}
  