How to increase a Number field width on a Configurable List widget

In Configurable Forms, how do I widen the "Number" box? Alternately, how do I add a sub label to it?

I am creating a form that uses the "Number" field, which at its current size doesn't show the full hint text.  I would like to either widen it or add a sub label to make it easier to read.

Thank you for contacting us.

Unfortunately, the sub labels are not supported on the Configurable list widget. Only the standard field labels are available.

In order to increase the number field width, please try adding the next CSS to the widget.

.col4 input {
width: 130px !important;
}

Where .col4 is the field column number and 130px is size in pixels. 

Please feel free to contact us if you need any further assistance.