Fixed issue with leading zero having different font

[AaronWatson2975]

Description

I'd like to start out by saying thanks for putting together this awesome library!

I ran into an intriguing glitch using this library in a project where we have custom fonts. There was inconsistency in the font display for the leading zero in the time input. With some research, I discovered that 'font' for the leading zero was not inherited from its parent.

To solve this, I've added the CSS rule font: inherit to the __inputGroup__leadingZero class. This aligns the font display of the leading zero with the rest of the input. I believe this fix will make the component more consistent when it comes to font styling.

Images

Before

After

This ensures the styling consistency between all elements of the component, providing a more predictable experience for future users.