I realize this is a very old question, but I stumbled across this problem today and I got it to work with
<div style="text-align:center;"> <button>button1</button> <button>button2</button> </div>
I realize this is a very old question, but I stumbled across this problem today and I got it to work with
<div style="text-align:center;"> <button>button1</button> <button>button2</button> </div>