diff --git a/static/js/chart_controls.js b/static/js/chart_controls.js
index 771ba8f..6214386 100644
--- a/static/js/chart_controls.js
+++ b/static/js/chart_controls.js
@@ -60,15 +60,15 @@ document.addEventListener("DOMContentLoaded", function () {
 
     // ——— Podział na kategorie ———
     toggleCategory?.addEventListener("click", function () {
-        const active = this.classList.contains("btn-primary");
+        const active = this.classList.contains("btn-outline-primary");
         if (active) {
-            this.classList.remove("btn-outline-light");
+            this.classList.remove("btn-outline-primary");
             this.classList.add("btn-outline-light");
             this.setAttribute("aria-pressed", "false");
             this.textContent = "Przełącz na kategorie";
             window.setCategorySplit(false);
         } else {
-            this.classList.add("btn-outline-light");
+            this.classList.add("btn-outline-primary");
             this.classList.remove("btn-outline-light");
             this.setAttribute("aria-pressed", "true");
             this.textContent = "Przełącz na sumy";