Sono quasi sicuro di non aver capito...

codice:
<style>
.sp1 {
	position: absolute;
	border: 1px solid black;
	background-color: silver;
	padding: 0px 6px 2px 5px;
}
.sp2 {
	position: absolute;
	border: 1px solid black;
	background-color: silver;
	padding: 1px 5px 1px 6px;
}
button {
	border: 1px solid black;
}
</style>

<span class="sp1" onmousedown="this.className='sp2'" onmouseup="this.className='sp1'"> pulsante </span>



<button onfocus="blur()">button</button>
ciao