Theming Views

I'm having difficulty getting some of the exposed filters in a Views query take a reasonable size.

e.g. the code generated for one is:
<div class="form-item" id="edit-filter1-wrapper">
<input type="text" maxlength="255" name="filter1" id="edit-filter1" size="60" value="" class="form-text form-autocomplete" />
</div>

A simple-minded approach would seem to be to add into style.css a rule such as:

#edit-filter1-wrapper .input {width:10em}

but it doesn't work.

Is it possible to do this with CSS or do I need a function override?

Chris