Issue with documents font

Issue with documents font

Hi I need to know how I can enlarge the font in my document area. Right now my font is very small making it very hard for me to read. Please put in simple terms. I'm new to zoho, and havent experiment much in my document area. I have tried to look around in the main frame of the document area, but couldnt find a way to enlarge font. Thanks for the help!!!!!