DEV: Use CSS custom properties for colors

DEV: Use CSS custom properties for colors

diff --git a/assets/stylesheets/group-tracker.scss b/assets/stylesheets/group-tracker.scss
index ce91d5c..6cde51d 100644
--- a/assets/stylesheets/group-tracker.scss
+++ b/assets/stylesheets/group-tracker.scss
@@ -1,5 +1,5 @@
 .group-tracker-nav {
-  background-color: $secondary;
+  background-color: var(--secondary);
   display: inline-flex;
   height: 100%;
   .btn {

GitHub sha: de7251450b0e5f0ea123558a527b6a077d372a4b