I would like to add styles on top of whats available in the package

Hello Folks, I am new to this framework and just started exploring it for one of my project.I would like to add some custom styles on top of whats available from the package. This is what I am trying.It is removing everything but what I kept below and what I understood is, basically by doing below I am overwriting whats avaialble. styleManager : { sectors: [{ name: 'Dimension', buildProps: ['width', 'min-height'], properties:[{ property: 'width', // Use 'property' as id min: 30 }] },{ name: 'Extra', buildProps: ['background-color', 'box-shadow'] }] }, Warm regards Milap