Increase code font size in firefox developer tool

Question

How to increase code fonts in Firefox developer tools? I know that there is a zoom function but I want to set the font size only for the code.

Answer 1

Some elements of Firefox can be styled in the userChrome.css file situated in your Firefox profile's chrome folder.
As of 2018, modify/create ~/.mozilla/firefox/[profile-name]/chrome/userChrome.css with something similar to:

@-moz-document url-prefix("chrome://devtools/content/") {
    * { font-size: 13px !important; }
}

Then restart Firefox.

The solution on the Mozilla forums almost has it right: https://support.mozilla.org/en-US/questions/1198481

Using Ctrl+= or Cmd+= was not ideal for me since it increased fonts for all the elements of the window, including the tab names.

Using .devtools-monospace { font-size: 13px !important;} was almost ok, but it did not affect the Debugger and Network tabs.

Using @bohag_bihu's solution had side effects for the address bar and some other text inputs.