Gap property in css class

So you can paste any style within a stylesheet it just takes a little bit of formatting for it to pick up, you just have to make sure to wrap the style in }...{style}...{. But with this method any other style within this class will only take effect if it is located in the injected style, for instance if i wanted to change the background color i would have to instead throw it in }...{backgroundColor:red;}...{ for it to work