CSS Grid, position absolute an element in a css grid item: IMPOSSIBLE

I have this situation: https://jsfiddle.net/rozkvsdh/5/

A CSS Grid, simply, but in some items, I need to put a ribbon or another div.

It's impossible!

How can I do?

 grid-item {
  background-color: lightgreen;
  display: flex;
  justify-content: center;
  align-items: center;
}

.ribbon-wrapper {
  width: 85px; // the length should be not in px I think!
  height: 88px; // the length should be not in px I think!
  overflow: hidden;
  //position: absolute; it doesn't work!
  position: relative;
  top: -3px;
  left: -3px;
  .ribbon {
    font: bold 15px sans-serif;
    color: #333;
    text-align: center;
    -webkit-transform: rotate(-45deg);
    -moz-transform: rotate(-45deg);
    -ms-transform: rotate(-45deg);
    -o-transform: rotate(-45deg);
    position: relative;
    padding: 7px 0;
    top: 15px;
    left: -30px;
    width: 120px;
    background-color: #ebb134;
    color: #fff;
  }
}