#searchsubmit { margin-left:-3px }
<form role="search" method="get" id="searchform" action="<?php echo home_url( '/' ); ?>">
<input class="search-box" type="text" value="" name="s" id="s" />
<input type="submit" id="searchsubmit" value="Search" />
</form>
but does not look right in iOS since the button is rounded