I'd like to increase the size of the textboxes for a Constant Sum question. I've consulted the responses on the forum, but I've been unsuccessful. I found a very relevant link from 12/2017 that looks relevant, using the following code:

<style>
.Skin .CS .SumInput input.InputText, .Skin .CS .SumTotal input, .Skin .CS input.SumInput {
width: 40px;
}
</style>

However, when I insert it into the Add Javascript:, I get an error message that says:
Invalid JavaScript! You cannot save until you fix all errors: Unexpected token <

I would think it's pretty straightforward using the Add Javascript, but I'm not a programmer; just need a little flexibility in the width of that textbox so that more than 4 or 5 digits are viewable. Any assistance is appreciated.