@mixin cover ($value){
    background-size:cover !important;
    background-repeat: no-repeat !important;
    background-position: $value !important;

}
@mixin  overlay ($value) {
    position: absolute;
    content:'';
    width:100%;
    height: 100%;
    top:0;
    right:0;
    bottom:0;
    left:0;
    z-index: 99;
    background-color: $value;
}