And if you don't want to use javascript as I don't then you can use the cascading option as follows:

a) put a div tag around the search control (or use what tag is is currently contained in) e.g. <div id="MySearchDiv"><dnn:SEARCH runat="server" id="dnnSEARCH" /></div>

b) in the style sheet put your style as follows: div#MySearchDiv input {style sttributes here}. Because there is a space between 'input' and 'div#MySearchDiv' this means apply this style to any 'input' tag which occurs under 'div#MySearchDiv'.

This solution avoids having to know the id of the rendered control.

No div doesn't make any difference :) just helps me remember where I might find that element in my code! :)