In Material UI, How can I override a selector selected component style?

Question

In Material UI, to extend the distance between MuiInputLabel and MuiInput, I have to override the marginTop of label + .MuiInput-formControl<

Answer 1

Here's the relevant JSS documentation:

https://cssinjs.org/jss-plugin-nested?v=v10.0.0-alpha.10#use--to-reference-selector-of-the-parent-rule

Here's the syntax you need:

const theme = createMuiTheme({
  overrides: {
    MuiInput: {
      formControl: {
        "label + &": {
          marginTop: "1.5rem"
        }
      }
    }
  }
});

Here's a working example: