asp.net-mvc-4 - Can an HTML dropdown be styled?

Question

I am using mvc4 with the Razor engine. Here's what I've tried:

<div class="editor-field">
    @Html.DropDownListFor(model => model.NewSymbol.Category.Id, new SelectList(Model.MarketCategories, "Id","Name"), new { @class = "dropdown" })
</div>

CSS is:

.dropdown {
    margin-top: 5px;
    margin-bottom: 10px;
    padding: 3px 2px;
    width: 312px; 
}

option {
    width: 312px !important;
}

Unfortunately I get something that looks like:

I am trying to get the drop down to be at least the same width as the 'select' element. I don't mind if it's wider if the text expands past 312px, but this narrow drop down looks goofy.

Thanks for your help everyone.