Responsive Search button

Hi all, could anyone show me the code for a simple search bar and submit button that is responsive (collapses on smaller screens) please?

I’m currently using the following and it’s just a bar without a button:
<form id="searchform" method="get" action="<?php bloginfo('home'); ?>/"> <input type="text" value="Type & [Enter]" onfocus="if (this.value == 'Type & [Enter]') {this.value = '';}" onblur="if (this.value == '') {this.value = '[SEARCH]';}" size="28" maxlength="50" name="s" id="s"> </form>