diff --git a/Gemfile b/Gemfile
index a76c33fb51c..df0a1e36513 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,3 +6,5 @@ group :test do
   gem "html-proofer", "~> 3.19.4"
   gem "rake"
 end
+
+gem "webrick", "~> 1.8"
diff --git a/assets/css/custom.scss b/assets/css/custom.scss
index 2ac41717b44..7bff576450e 100644
--- a/assets/css/custom.scss
+++ b/assets/css/custom.scss
@@ -62,6 +62,16 @@ blockquote {
   line-height: 0;
 }
 
+nav.main-nav {
+  position: fixed;
+  top: 0;
+  left: 0;
+  width: 100%;
+  z-index: 10; 
+  background-color: #fff; 
+  transition: all 0.3s ease-in-out;
+}
+
 .main-links {
   a {
     &:hover {