added scroll functionality for navbar: hide on scroll down, show on scroll up
diff --git a/dev/scss/header/header.scss b/dev/scss/header/header.scss
index b640531..04e318e 100644
--- a/dev/scss/header/header.scss
+++ b/dev/scss/header/header.scss
@@ -32,6 +32,10 @@
     position: fixed;
     top: 0;
     z-index: 999;
+    transition: top .3s ease-in-out;
+    -o-transition: top .3s ease-in-out;
+    -moz-transition: top .3s ease-in-out;
+    -webkit-transition: top .3s ease-in-out;
 
     &-group {