--- a/browser/extensions/onboarding/content/onboarding.css
+++ b/browser/extensions/onboarding/content/onboarding.css
@@ -130,18 +130,19 @@
 
 #onboarding-tour-list > li:dir(rtl) {
   background-position: right 27px center;
 }
 
 #onboarding-tour-list > li.onboarding-complete::before {
   content: url("img/icons_tour-complete.svg");
   position: relative;
-  left: 6px;
+  offset-inline-start: 3px;
   top: -10px;
+  float: inline-start;
 }
 
 #onboarding-tour-list > li.onboarding-complete {
   padding-inline-start: 29px;
 }
 
 #onboarding-tour-list > li.onboarding-active,
 #onboarding-tour-list > li:hover {