Just wondering if rollup-plugin-scss-lit is still the best way to use scss files with lit custom html elements. The last I saw were SO posts from 2022 or so, nothing on the lit site when searching for scss.
Currently, there are no much information for using scss (or any of the css preprocessors) with lit-element but read about that plugin rollup-plugin-scss-lit.
If you don't like that, you can also check rollup-plugin-lit-css, this is for css but there is the part where you can include 'scss' and set how to transform it to css
Also if I am guessing correctly, you are using rollup for your bundling, if yes you can read up on how to use scss with rollup. You can also check rollup-plugin-sass to see if that will help you