Merged PR 3080: fix firefox bugs

fix firefox bugs, reported in github issue https://github.com/microsoft/coyote/issues/52

docs/_sass/main.scss

@@ -446,12 +446,14 @@
      @include screen(lg, min) {
        width: 300px;
        position: fixed;
+       top: 0;
        z-index: 300;
      }
 
      @media (min-width: $breakpoint-sm) and (max-width: $breakpoint-lg) {
        width: 27%;
        position: fixed;
+       top: 0;
        z-index: 300;
      }
 

docs/assets/js/navmenu.js

@@ -54,7 +54,7 @@ function handle_resize()
             var search_top = $(".search-wrapper").offset().top;
             var search_offset = search_top - window.scrollY;
             var top = wrapper.offset().top;
-            var search_height = search_offset + top - search_top;
+            var search_height = search_offset + top - search_top + 100;
             var scroller_height = height - search_height;
             wrapper.height(scroller_height);
         } else {