Using the Ubuntu font in Vivaldi (Ubuntu 16.04)

Somehow I couldn't seem to make Vivaldi display the webpages in Ubuntu font, despite having changed the fonts to it. Asked in the Vivaldi forums and got a useful answer:

As I already have Stylish (the add-on), I created a new style and as text I put in the CSS this:

html, body { font-family: "Ubuntu" !important}

Tell the system to "beautify" it:

body {
font-family: "Ubuntu" !important

and give it the name "ubuntu" and save.

Restart the browser.

As I have next to no ideas about CSS this is perfect for me.

--- Crossposted from Dreamwidth ---