Hi @ilanusse
Use custom-css settings if the CSS needs to be merchant/staff facing, or accessible in the visual theme editor.
https://help.shopify.com/en/manual/online-store/themes/theme-structure/extend/add-css
Otherwise in liquid itself use and get the actual section.id, not the section ID html attribute value,
#{{section.id }}--variantionA { color: red; } See the dawn theme reference for css use cases [https://github.com/Shopify/dawn](https://github.com/Shopify/dawn)