Stuck on how to edit Authorize.net form on payments page

[nancyjan]

The Authorize.net form on my order page shown here https://www.antiquereproductionjewelry.com/order?multi-shipping= then click on the 3rd payment selection for the Authorize.net form to open has 2 text fields that are partially hidden and buyers can not see the text in the check box.

 

I've looked through all the css files that I think control this form and can not find where I can set the text block widths. On the themes global css I can set everything but the width. I have isolated the lines I need to set the widths on from the browser

 

<div style="width: 0px;" class="styled-select"><div style="width: 0px;" class="styled-select-text">American Express</div><select style="opacity: 0; position: relative; left: -1px; height: 24px; z-index: 100;" id="cardType">                    <option value="AmEx">American Express</option>        <option value="Visa">Visa</option>    <option value="MasterCard">MasterCard</option>    
<option value="Discover">Discover</option>                
</select></div>

 

When I inspect the element with Foxfire browser and replace the above 0px with 100px for example the card type & Expiration Date text field boxes expand to show the text. I just can't find what file to edit the width in. Can someone please point me in the right direction?