根据输入更改输入数字类型的CSS

I'm not sure if what i'm asking is possible. But i can't find anything on Google to figure this out. Here's what i'm trying to do... I have 5 input tags, all of them are numbers. I want the border to become green if the value is a valid number(number within max/min value), if letters(or invalid numbers) are present, i want the border to become red. I tried to figure this out on my own yesterday, but cannot.I'm not sure if what i'm asking is possible. Bu