How to add a character countdown to cart note section

[lkverdant]

Hi,

Hope someone can help me with adding a character countdown for the note section within a slide out cart?

I've managed to limit input to 150 characters, but I can imagine it frustrating for customers to not see any further typing after 150 characters with no warning.

So ideally the method where its 150/150 <the left side lowers as you type

or

Just shows 150, which reduces as you type.

Here is my cart > using the Broadcast theme.

Thank you so much