I need to apply styling to the registration complete and waiting list complete pages.
The registration complete page has id="eb-registration-complete-page" but there is no id specified for the waiting list complete page. Would you be able to add one please?
I can see where you have added that class in the code but I think that might be the wrong place - the code used to display waitinglist confirm page is in site\themes\default\waitinglist\default.php. I think it just needs the equivalent id and classes from the \complete\default.php file you've amended.
I also get a blue bar for the info message on this page that isn't shown on the registration complete page so maybe that line of code could also be updated from the registration complete page so that they match?
I think I understand your requirement now. I updated code on server. You can access to My Downloads menu item, download latest package, upgrade it to your site then check it again. It should work as expected