"All Buttons Must Die!" is a pure CSS library of buttons. The entire library is just ~15KB minified. Althought the project is still in its early alpha days, it's mostly usable and most buttons are pretty reliable.
With that being said, use at your own risk
The easiest way is to just include ABMD via CDN
Copy-paste the stylesheet
<link> into your
<head> to load ABMD's CSS
<link rel="stylesheet" type="text/css" href="https://cdn.jsdelivr.net/npm/abmd/css/buttons.css">
You can also install ABMD with NPM
npm install abmd
And don't forget to include the CSS file!
As a last note, you can see the project over at GitHub