You changed the wrong area. Remember.... the lines in the config file read
replace_zlib = location, ORIGINAL_VALUES, NEW_VALUES
So you don't change the section in the ORIGINAL_VALUES area, rather in the NEW_VALUES area.
What the error is saying is that the data in the existing file does not match the ORIGINAL_VALUES settings, and this is because you changed the font sizes in it.
The examples given, all of the NEW_VALUES are way way shorter, and simpler CSS than the ORIGINAL_VALUES.
See posts
https://www.mobileread.com/forums/sho...5&postcount=82 and
https://www.mobileread.com/forums/sho...7&postcount=83 for more discussion on both the syntax of the patcher, and a "pretty printed" version of the CSS. Remember that the \n's and \t's are nothing more than new lines, and tab characters to make the CSS easier to read to the human eye.