I changed gnome-shell.css to match my font and font size (Tw Cen MT 11). But then some icons in the topbar and user menu became small, eg. brightness, volume and wifi icon (battery icon is fine).
![font-size: 11pt;](https://user-images.githubusercontent.com/62117272/76717244-3e1e1600-675d-11ea-8558-d9391628133c.png)
In case of font-size: 10.5pt;
Everything is ok.
![font-size: 10.5pt](https://user-images.githubusercontent.com/62117272/76717514-db794a00-675d-11ea-98c0-fa472d15bc4e.png)
Paper icon theme doesn't have this issue.
![Paper Icon Theme](https://user-images.githubusercontent.com/62117272/76717571-1bd8c800-675e-11ea-9726-dde8f140ab18.png)