Invisible text in form fields

I have a Contact Form 7 form on a site that began with the Auto Demo (Integrity Dark).

The input typed into a text field is not visible.

Editing the css has no effect.

The same issue appears here:

http://demo.theme.co/auto/contact/

Please advise how to make the text typed into these form fields visible (and larger too).

Thank you.

UPDATE: Issue occurs for me on Windows/Firefox. Client has the same issue on Mac/Safari. I do not have the issue on Windows/Opera.

The problem also happens on Android/Firefox.

It may help you to know that, in the cases where the typed text is not visible, the placeholder text is not visible either.

SOLVED:

The problem is caused by a style declaration for height in the original CSS. Changing the CSS (in a child theme) fixed the problem. This is what I used:

input {
height: auto !important;
}

Thanks for letting us know!