Bulma v1 is a full rewrite of the framework using Dart Sass, which is the the primary implementation of Sass. While this affects a few development details, everything has been done to make the transition as easy as possible.
What remains the same
All HTML snippets are the same. This means you don't need to update your markup. This is important because it means, if you're using Bulma straight "out of the box", you don't need to change anything.
You can just swap
[email protected]/css/bulma.min.css with...