R – Silverlight BrowserInformation for Chrome and Firefox

OK, I've found it. This is probably the cleanest and easiest solution out there and does not rely on JavaScript being turned on.

@-moz-document url-prefix() {
  h1 {
    color: red;
  }
}

<h1>This should be red in FF</h1>

It's based on yet another Mozilla specific CSS extension. There's a whole list for these CSS extensions right here: Mozilla CSS Extensions.

You can change input box styles as well as text styles inside input box:

Here you can use any color e.g. white, #DDD, rgba(102, 163, 177, 0.45).

But transparent won't work here.

/* Change the white to any color */
input:-webkit-autofill,
input:-webkit-autofill:hover, 
input:-webkit-autofill:focus, 
input:-webkit-autofill:active{
    -webkit-box-shadow: 0 0 0 30px white inset !important;
}

Additionally, you can use this to change the text color:

/*Change text in autofill textbox*/
input:-webkit-autofill{
    -webkit-text-fill-color: yellow !important;
}

Advice: Don't use an excessive blur radius in the hundreds or thousands. This has no benefit and might put processor load on weaker mobile devices. (Also true for actual, outside shadows). For a normal input box of 20px height, 30px ‘blur radius’ will perfectly cover it.