Material UI (React): how to style the Input wrapping the Select? - reactjs

Question

I have the following JSX:
<FormControl>
<InputLabel>My label</InputLabel>
<Select>
...
</Select>
</FormControl>
I use the classes prop to style various aspects of the FormControl and Select. The trouble is that the Select component implicitly wraps itself with an Input component, and thus in reality looks something like this:
<FormControl>
<InputLabel>My label</InputLabel>
<Input>
<Select>
...
</Select>
</Input>
</FormControl>
That's where I'm having problems: how can I style the Input that is wrapping the Select? I've looked at the CSS APIs for both Select and FormControl, and neither of them allow you to style that Input.
I know I can add a className to the FormControl and then style it using an external stylesheet, but I want to style it on the component level.
Any ideas?
EDIT:
A snippet of my code (with dummy content), for illustration (was requested):
<FormControl
classes={myClasses.formControl}
>
<InputLabel
htmlFor='country'
classes={myClasses.inputLabel}
>
Select country
</InputLabel>
<Select
value={countryCode}
onChange={onInputChange}
inputProps={{
name: 'countryCode',
id: 'country',
}}
classes={myClasses.select}
>
<MenuItem value='US'>United States</MenuItem>
<MenuItem value='GB'>United Kingdom</MenuItem>
<MenuItem value='FR'>France</MenuItem>
</Select>
</FormControl>

Answer 1

You can do it via standard css import (look at generate code and retrieve the css path) or you can style it using a wrapper and styling it with styled-components. A snippet with a real case would be useful for me to be more specific.

Answer 2

Okay, I've found the solution.
To style the wrapping Input component, you need to explicitly define it in the Select's input prop, and then pass the classes prop to that Input.
Here is an example:
<Select
input={
<Input
classes={myClasses.input}
/>
}
>
...
</Select>