I am looking at MDN for spinners (arrows for input type="number") and it says it is non standard. The way I remember is MDN also tell you what to use but in this case, it isn't. 
My problem is that while I am using 
input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  -moz-appearance: textfield;
  margin: 0;
}
It works for chrome but not for firefox. So I am guessing due to non-standard it is not applying, What is the "Standard" Workaround for it?
 
    