CSS Box set exercise does not allow me to proceed

I am receiving this message.

Hmm. We’re having trouble finding that site.

We can’t connect to the server at ae74ccd0916f49aaaf8d0c331e70a325.cc-propeller.cloud.

Tried from Chrome and Firefox.

Here is the page link.

https://www.codecademy.com/paths/web-development/tracks/getting-more-advanced-with-design/modules/learn-css-box-model/lessons/box-model-intro/exercises/box-margin-auto

I can not proceed to next step of the lesson either.

Here is what I listen to calm myself, as an addition.

Nevermind, View Solution option allows me to proceed. Although I hope this issue will be fixed soon.