call functions file in docs css

assets/scss/_content.scss

@@ -6,8 +6,9 @@
 
 .bd-content {
   // Hack the sticky header
-  h2[id],
-  h3[id] {
+  > h2[id],
+  > h3[id],
+  > h4[id] {
     &::before {
       position: relative;
       z-index: -1;

assets/scss/docs.scss

@@ -24,6 +24,7 @@
 // Happy Bootstrapping!
 
 // Load Bootstrap variables and mixins
+@import "../../scss/functions";
 @import "../../scss/variables";
 @import "../../scss/mixins";