center align a button

Hi I've used the below css and code to add a button to a page:

css: `.button.sun-flower,
.button.sun-flower:visited {
background: #0ebeea;
color:#FFF;
}

.button.sun-flower:hover,
.button.sun-flower:active {
background: #0ebeea;
color:#FFF;`

html: <a href="URL FOR YOUR BUTTON">Click here to order your Itinerary!</a>

What do i add to either of these to make it so the button is centered?

Thanks!

Jamie