function hide_header(){
?>
<script>
(function($){
  'use strict';
  var c, 
  currentScrollTop = 0,
  header = $('#header');

   $(window).scroll(function () {
      var a = $(window).scrollTop();
      var b = header.height();
     
      currentScrollTop = a;
     
      if (c < currentScrollTop && a > b  ) {
        header.addClass("hide-header");
      } else if (c > currentScrollTop && !(a <= b)) {
        header.removeClass("hide-header");
      }
      c = currentScrollTop;
  });
})(jQuery);   
</script>
<?php
}
add_action('wp_footer', 'hide_header');
.responsive:not(.av-burger-overlay-active) #header {
  top: 0px;
  -webkit-transition: transform 0.3s ease-in;
  transition: transform 0.3s ease-in;
}

.responsive:not(.av-burger-overlay-active) #header.hide-header {
  -webkit-transition: transform 1.5s ease-in;
  transition: transform 1.5s ease-in;
}

.responsive:not(.av-burger-overlay-active) #main {
  top: 0px;
  -webkit-transition: padding-top 0.3s ease-in;
  transition: padding-top 0.3s ease-in;
}

.responsive.av-burger-overlay-active #header {
  position: fixed !important;
}

@media only screen and (min-width: 990px) {
  .responsive:not(.av-burger-overlay-active) #header.hide-header {
     transform: translateY(-116px);
  }
}

@media only screen and (min-width: 768px) and (max-width: 989px) {
  .responsive:not(.av-burger-overlay-active) #header {
    position: fixed !important;
    top: 0;
  }
  .responsive:not(.av-burger-overlay-active) #header.hide-header {
     transform: translateY(-115px);
  }
  .responsive #top #main {
     padding-top: 115px !important;
  }
  .responsive #top .header_bg {
    background-color: #FFF ;
  }
}

@media only screen and (max-width: 767px) {
  .responsive:not(.av-burger-overlay-active) #header {
    position: fixed !important;
    top: 0;
  }
  .responsive:not(.av-burger-overlay-active) #header.hide-header {
     transform: translateY(-115px);
  }
  .responsive #top #main {
     padding-top: 115px !important;
  }
  .responsive #top .header_bg {
    background-color: #FFF ;
  }
}