How to get more width on product-custom-fields ?

[jantabak]

I try to get some more width on the display of product custom fields. On a trial & error way I made overrides for vm-ltr-site.css and sublayouts/products_horizon.php. I can't find where to modify any style or PHP-code to get some more width on the selectbox dropdown. I added an image of the issue as attachment, the yellow background color is just for testing and point me in the right direction.
Can anyone give me a hint on what file and css-tag I can create some more width at this point?

[GJC Web Design]

live url?

[GJC Web Design]

prob easier to uncheck "Use jQuery chosen for dropdowns in FE" on vm config->config->templates

if not something like

.product-field-display .chzn-container, .product-field-display .chzn-drop {
  width: 200px !important;
}
.product-field-display .chzn-drop li {
display.block !important;
}

[jantabak]

Wow, that's it?
I switched off jQuery in VM-config and it's just like I mentioned....
Thank you and best regards!
Jan