In this tip ill show you how to reduce the title bar height in Gnome3. Gnome shipped with incredibly high vertically padded title bars which waste a lot of screen real estate. We can reduce the hight using a small bit of CSS code.
We don't need any special permissions to create this css file. We will do this with your local user account.
Example A before CSS

Example B before CSS

OK launch your favourite terminal. Then Type:
This will open a blank css file.

Now add this CSS Code to the blank file.
You can download a pre-made CSS file Here and place it in ~/.config/

Now we need to restart Gnome Shell. Press and hold the Alt key and tap F2 then type r and hit enter.

As you can see we have reduced the size of the titlebar and removed that horrible Separating line.

Example A After CSS

Example B After CSS

Thank you for reading.