Search Form Sizing IE

Are there any site search styles that do not change size when a different browser is used? With Moxilla my search form is perfectly aligned, with IE it can be twice the size, bumping the sidebar.

The current coding I’m using is as follows.

<h2><span><?php _e('Site Search'); ?></span></h2>
<form method="get" id="searchform" action=https://mail.yahoo.com/config/login?/"<?php echo $_SERVER['PHP_SELF']; ?>">
<div>
<input type="text" value="<?php echo wp_specialchars($s, 1); ?>" name="s" id="searchbox" />
<input type="submit" id="searchbutton" value="search" />
</div>
</form>

Some coding would be of great help. The sidebar is from the site https://www.thegolfdrillguru.com

That line of coding is currently removed from the left sidebar so it fits.

Thanks in advance!