CSS Syntax Error

After updating WP and Plugins in our site, a new HTML error has come up:
You can see it in #14 validator.w3.org/nu/?showsource=yes&doc=https%3A%2F%2Fwww.econcba.gr%2F
The error in in INDEX’s embedded CSS code:
#pg-2-2 { margin-bottom:30px } #pg-2-0 , #pg-2-1 { margin-bottom:px } #pgc-2-2-0 , #pgc-2-2-1 { margin-bottom:20px }
I’m looking for the file (PHP / CSS) that has this code.

Thanks in advance.

The page I need help with: [log in to see the link]