Styling the div components

Attaching the code and the result. Please find them. I want the row that contains both the title and the slogan to be in a specific color. The className for this div is banner.
I have done that in a css file.something like this
But I did not get the desired result

Could set the style component of the html.Div to style={'backgroundColor':'blue'} or whatever color you are intending. Don’t have too much experience with CSS to know why your method isn’t working.