Bug 1377129 - [RTL] bottom onBoarding tour notification doesn't display well on RTL builds (main content) r=mossop

MozReview-Commit-ID: 8gnVYC1yjKw

--HG--
extra : rebase_source : 3e15ab3208fb380d7a196bb92422518ddafd09f7

browser/extensions/onboarding/content/onboarding.css

@@ -397,8 +397,8 @@
   display: flex;
   align-items: center;
   position: absolute;
-  offset-block-start: 50%;
-  offset-inline-start: 50%;
+  top: 50%;
+  left: 50%;
   transform: translate(-50%, -50%);
 }