Error 404, Page Not Found

Hello. I’m currently taking the HTML & CSS course. But I have this error on Sylabus 4 (Introduction to CSS) and I cannot advance the lesson, the page is not found. I have completed 69% of this topic. I’m aware that they are going to upgrade the course sometime soon, but the rest of it runs well. I couldn’t find an email of codeacademy asking for help. Is there anything I can do? Thank you all in advance

It probably a glitch, you don’t need to upgrade to complete the course.

CSS an overview:

Design a button for your website:

###Also keep in mind
That the above course will be replaced a preview is out and I would recommend starting that course: