Dropdown menu same style as text field

Select elements are pretty tough to style uniformly, cross-browser as most of the styling is dictated by the browser. Do you have a link to your form so I can see what you have so far?

Yeah I don't think you're going to be able to match that up exactly, besides the contents of the drop down doesn't really need to be that wide anyways to accomodate prefixes. At any rate, you can isolate and try to target that field individually with:

[css]
#input_1_4 {
width: 79% !important;
-webkit-appearance: none;
box-sizing: content-box;
}

You can also try taking off some of the browser-defined styles like the one example above.

Edit: This is pretty close for webkit at least. Screenshot

You're not going to be able to universally apply this and have it exact because that select field you will most likely need to target individually. But you could try something like:

[css]
.gform_wrapper .right_label input.medium, .gform_wrapper .right_label select.medium, .gform_wrapper .left_label input.medium, .gform_wrapper .left_label select.medium {
font-size: 16px!important;
width: 80%!important;
box-sizing: content-box !important;
padding: 3px!important;
height: 20px;
}

Here is the documentation on how the structure is laid out.

http://www.gravityhelp.com/documentation/page/Design_and_Layout

You can also use tools such as chrome developer tools and firebug for firefox to inspect the elements and target them as you wish.