Recently I tried enabling CSS merge inside System->Configuration->Developer
But this is breaking complete UI in front end. ** It seems like CSS os having issues & I have to make CSS error free**.
Can anyone list out what points have to check in CSS to avoid such issues.
Best Answer
Copy the content of your CSS and copy it into the W3C validator: https://jigsaw.w3.org/css-validator/
It will list the errors and once you've fixed them, merge CSS will come back normal