The customizer “Additional CSS” box is too small for me to use. Is there a way to expand this box, or would it be easier to use “Simple CSS” global box?
Is there any impact on performance if I use “Simple CSS” global css box?
not really – Simple CSS won’t effect performance – so that is the better option.
Worth looking at using a desktop IDE – an easy one to get into is Brackets. Write your CSS in the IDE and then copy and paste.