create css badge with pseudo-element only

Question

I have an element with a known ID I can target. How could I create a bestseller-badge like this with css only? I cannot change the html.

I know how to create this but only if I could edit the html, which I cannot:

.box {
  width: 200px; height: 300px;
  position: relative;
  border: 1px solid #BBB;
  background: #EEE;
}
.ribbon {
  position: absolute;
  right: -5px; top: -5px;
  z-index: 1;
  overflow: hidden;
  width: 75px; height: 75px;
  text-align: right;
}
.ribbon span {
  font-size: 10px;
  font-weight: bold;
  color: #FFF;
  text-transform: uppercase;
  text-align: center;
  line-height: 20px;
  transform: rotate(45deg);
  -webkit-transform: rotate(45deg);
  width: 100px;
  display: block;
  background: #79A70A;
  background: linear-gradient(#9BC90D 0%, #79A70A 100%);
  box-shadow: 0 3px 10px -5px rgba(0, 0, 0, 1);
  position: absolute;
  top: 19px; right: -21px;
}
.ribbon span::before {
  content: "";
  position: absolute; left: 0px; top: 100%;
  z-index: -1;
  border-left: 3px solid #79A70A;
  border-right: 3px solid transparent;
  border-bottom: 3px solid transparent;
  border-top: 3px solid #79A70A;
}
.ribbon span::after {
  content: "";
  position: absolute; right: 0px; top: 100%;
  z-index: -1;
  border-left: 3px solid transparent;
  border-right: 3px solid #79A70A;
  border-bottom: 3px solid transparent;
  border-top: 3px solid #79A70A;
}

<div class="box">
   <div class="ribbon"><span>Bestseller</span></div>
</div>

The thing is I only have the parent box and not the ribbon inside. I cant input html.

Answer 1

Because in pseudo elements you can't put any html markup, you need to get clever with just using simple shapes and combining them together. Additionally, you can't have multiple :after pseudo elements, so we are limited to just two shapes (one for :after and one for :before). The one in :after could be the bestseller front of the badge, with text. The trickiest part was to get the clip-path: polygon(...points) to get right so that we get the effect of trimmed ribbon. Fortunately, Firefox dev tools have a nifty polygon modification tool that was very helpful. Getting the two little corners that make the "wrap around" effect was a bit trickier, but putting it in a :before pseudo element with z-index: -1 and a little hand-tweaked offset did the trick. The end effect is below:

.box {
  width: 200px; height: 300px;
  position: relative;
  border: 1px solid #BBB;
  background: #EEE;
  margin: 20px;
  display: inline-block;
}
.bestseller:before {
  content: "";
  z-index: -1;
  overflow: hidden;
  transform: rotate(-135deg);
  width: 120px;
  display: block; 
  background: #79A70A;
  background: linear-gradient(#9BC90D 0%, #79A70A 100%);
  box-shadow: 0 3px 10px -5px rgba(0, 0, 0, 1);
  position: absolute;
  top: 34px;
  right: -16px;
  clip-path: polygon(120px 20px, 90px -10px, 30px -10px, 0px 20px, 10px 30px,  110px 30px);
  height: 20px;
  width: 120px;
}
.bestseller:after {
  content: "bestseller";
  z-index: 1;
  overflow: hidden;
  font-size: 10px;
  font-weight: bold;
  color: #FFF;
  text-transform: uppercase;
  text-align: center;
  line-height: 20px;
  transform: rotate(45deg);
  width: 120px;
  display: block; 
  background: #79A70A;
  background: linear-gradient(#9BC90D 0%, #79A70A 100%);
  box-shadow: 0 3px 10px -5px rgba(0, 0, 0, 1);
  position: absolute;
  top: 20px; right: -30px;
  clip-path: polygon(120px 20px, 90px -10px, 30px -10px, 0px 20px, 10px 30px,  110px 30px)
}

<div class="box">
</div>

<div class="box bestseller">
</div>