diff --git a/static/css/04-interactive/_buttons.css b/static/css/04-interactive/_buttons.css
index 0a714e6..4044b8e 100644
--- a/static/css/04-interactive/_buttons.css
+++ b/static/css/04-interactive/_buttons.css
@@ -11,7 +11,7 @@
     left: 2rem;
     width: 50px;
     height: 50px;
-    background: rgba(92, 89, 182, 0.7); /* Purple (#5c59b6) with transparency - distinct from info button blue */
+    background: var(--black-bar); /* Dark by default like other buttons */
     color: white;
     border: none;
     border-radius: 50%;
diff --git a/static/css/04-interactive/_scroll-behavior.css b/static/css/04-interactive/_scroll-behavior.css
index 843569a..9aa641a 100644
--- a/static/css/04-interactive/_scroll-behavior.css
+++ b/static/css/04-interactive/_scroll-behavior.css
@@ -78,7 +78,7 @@
     left: 2rem;
     width: 50px;
     height: 50px;
-    background: rgba(52, 152, 219, 0.7); /* Blue with transparency - distinct from zoom purple */
+    background: var(--black-bar); /* Dark by default like other buttons */
     color: white;
     border: none;
     border-radius: 50%;