<div id="banner">DEVMODE</div>

<style>
  #banner {
    width: 200px;
    background: red;
    color: #fff;
    position: fixed;
    text-align: center;
    top: 25px;
    line-height: 40px;
    right: -50px;
    left: auto;
    -ms-transform: rotate(45deg);
    -webkit-transform: rotate(45deg);
    transform: rotate(45deg);
    z-index: 100;
  }
</style>
