Form field size (gravity forms)

Hi, how can we adjust the form field sizes to make them smaller, both in height and in length? We’ve tried a few settings, including within Gravity Forms with mixed results and suspect the theme css may be overwriting the Gravity Forms settings.

Specifically, the form on this page should be showing in the sidebar: https://www.guttershutter.com/GS2015/become-a-dealer/ The title is in the sidebar “Get Dealer Information” but the form itself appears below.

Thanks in advance, and apologies if this is a gravity forms question instead of a theme question.

Here’s what we have added so far:

.gform_wrapper {
    margin: 1em 0;
    max-width: 50%;
    overflow: inherit;
}

Thanks, Tom