Pure CSS 3 ribbons

ribbon.sass

.ribbon
  overflow: hidden
  // top left corner
  position: absolute
  right: -3.5em
  top: 2.5em
  // 45° clockwise rotation
  +rotate(45deg)
  +box-shadow(0 0 1em #888)
  +background-image(linear-gradient(left, #050, #080, #090, #080, #050))
  &.staging
    +background-image(linear-gradient(left bottom, #800, #A00, #B00, #A00, #900))

  span
    border: 1px solid rgba(255, 255, 255, .6)
    color: #fff
    // text-transform: uppercase
    font-variant: small-caps
    display: block
    font-weight: bold
    margin: 1px 0
    padding: .5em 0
    width: 15em
    text-align: center
    text-decoration: none
    text-shadow: 0 0 0.5em #444