Where to input custom css code for matrix field?

Where are you inputing this code within the table matrix setup?

Hello Fireconsultingltd,

I did check your last edited form and did not find any matrix field in form. You seems to have added "Matrix Dynamique" widget in form. Please check the screenshot below how to inject custom css code in widget:

 

If you want to add custom css code for the "Matrix" field, Please check the screenshot below where css code needs to be added in form:

 

Hope this helps.

Do get back to us if you have any questions.

Thank you!