2 answers

Hi Florian,It has just come to my attention that since Spring '17 we can use the global var $Asset in visualforce pages to access the lightning design system. So if you're using your React within a VF it would work for you as well.https://releasenotes.docs.salesforce.com/en-us/spring17/release-notes/rn_vf_asset_variable.htm (http://https://releasenotes.docs.salesforce.com/en-us/spring17/release-notes/rn_vf_asset_variable.htm)