Fix for Firefox for dark KDE/GTK themes

userContent.css

/*
To be placed in ~/.mozilla/firefox/YOUR_PROFILE/chrome/

Got it here: http://stackoverflow.com/a/22419524;
*/

input {

border: 2px inset white;
background-color: white;
color: black;
-moz-appearance: none !important;
}

textarea {
border: 2px inset white;
background-color: white;
color: black;
-moz-appearance: none !important;
}

select {
border: 2px inset white;
background-color: white;
color: black;
-moz-appearance: none !important;
}

input[type="radio"],
input[type="checkbox"] {
border: 2px inset white ! important;
background-color: white ! important;
color: ThreeDFace ! important;
-moz-appearance: none !important;
}

*|*::-moz-radio {
background-color: white;
-moz-appearance: none !important;
}
button,
input[type="reset"],
input[type="button"],
input[type="submit"] {
border: 2px outset white;
background-color: #eeeeee;
color: black;
-moz-appearance: none !important;
}

body {
background-color: white;
color: black;
display: block;
margin: 8px;
-moz-appearance: none !important;
}