What am I doing wrong with this CSS?

I am using a code from codepen and I have managed to make it work with my website. I am no coding expert so this is quite exciting for me.

I am trying to use these content blocks on my website and I am wanting to add an image to the background of the content block. Right now the code is set up as a color background.

Here is the original code: https://codepen.io/ckor/pen/lBnxh

I added this to the code to add a background image I uploaded to a online file host.
background-image: url('https://s15.postimg.cc/r8cb2jiu3/banner_test.jpg');


Then I get this error from the website when trying it:
Invalid CSS after "": expected selector, was "!*"

Sites are made up of blocks and I just want to create nice looking responsive blocks. This codepen code is perfect if only I can get images to run in the background to go along with the text.

 

It has been fixed! Thanks

 

Does not look fixed to me. Looks the same as what you posted. So, how exactly did you fix it?

 

Based on the fact that the OP says that the situation has been resolved, but cowsgonemadd3 said that there are still issues, that caching is enabled for anonymous users, but not for logged in users. As such, it sounds like the minimize scripts for css need to be rebuilt so that anonymous users can view the changes.