Plain CSS
Usage with plain CSS
It is important to change the style precedence order with the help of the
StylesProvider component, otherwise the internal MUI classes will overwrite
your styles.
Example
@react.component
let make = () =>
  <Mui.StylesProvider injectFirst=true>
    <Mui.Button
      color=#primary
      className="my-global-class-name"
      onClick=ignore>
      {React.string("Hello, plain CSS & MUI!")}
    </Mui.Button>
  </Mui.StylesProvider>