If anyone is still having issues - earlier in the day the trick to getting in, when you were still stuck on the countdown or the pink castle screen, was to find an alternate means of actually logging in. Those countdown and pink castle screens are just waiting to get you to the login prompt - I believe. So this was the trick to do:
Open the main mydisneyexperience page:
https://disneyworld.disney.go.com/
Do not hit the login....instead, go to find a Dining Reservation. Select any dates and search for any available ones out there - click the available time and it will take you to the login screen where you can login. After that it will direct you to finalize the reservation...hit the CANCEL button on the bottom left. This will send you back to the main screen
At this point, it may say you are signed in (hopefully) or may say you still need to sign in (not sure if that will happen for all), but at this point just use the pulldown to the Disney Park Pass System...I think this might be the direct link:
https://disneyworld.disney.go.com/experience-updates/park-reservations/