Font size of programatically populated div

I am displaying a div after clicking a an ICON

the div is filled up with data using php script…

how can i change the font size of data displayed in DIV as per window size ?

If you define the font size of the text using VW (viewport width) units, it will change based on the viewport’s size. Here’s more info on how to set that: Responsive font-size

Also check out: https://css-tricks.com/viewport-sized-typography/