-webkit-transform: rotate(90deg); The other answers are correct but they led to some alignment problems. On trying out different things this CSS piece code worked perfectly for me.
.vertical{ writing-mode:tb-rl; -webkit-transform:rotate(90deg); -moz-transform:rotate(90deg); -o-transform: rotate(90deg); -ms-transform:rotate(90deg); transform: rotate(90deg); white-space:nowrap; display:block; bottom:0; width:20px; height:20px; } Cheers!!!