--- a/browser/extensions/onboarding/content/onboarding.css
+++ b/browser/extensions/onboarding/content/onboarding.css
@@ -19,16 +19,17 @@
   display: none;
 }
 
 #onboarding-overlay.onboarding-opened {
   display: block;
 }
 
 #onboarding-overlay-button {
+  padding: 0;
   position: absolute;
   cursor: pointer;
   top: 30px;
   offset-inline-start: 30px;
   border: none;
   /* Set to none so no grey contrast background in the high-contrast mode */
   background: none;
 }