How can I use/access styles from the Design System?

I want to apply a style from Design System on a button I created with Custom Field Renderer.

Code:

const FieldRenderer = skuid.component.FieldRenderer;

return new FieldRenderer({

readModeStrategy: "virtual",



read: function (fieldComponent) {



    let h = fieldComponent.h,



        context = fieldComponent.cpi.getContext();



        let { element, field, model, row, value } = context;



    



    let childNodes = [];



    childNodes.push(



        h("button", {



            onclick(event){



                console.log('click1');



            }



        }, [



            `+`,



        ]));



    if(row.Added_By_User__c){



        childNodes.push(



        h("button", {



            onclick(event){



                console.log('click2');



            }



        }, [



            `-`,



        ]));



    }



    return h('div', {}, childNodes);



},

});