I'm trying to replicate a design using CSS, a simplified example of this is below:

The pink background should be 50% opacity, however the blue offset shadow/border should be 100% opacity.

I can do the general shapes but not in a way to achieve the desired transparency.

Here is an attempt I made:

.container {
  position: relative;
  margin: 0 auto;
  width: 600px;
  height: 200px;
}

.content-wrap {
  position: relative;
  z-index: 1;
  filter: drop-shadow(13px 15px 0 rgb(0,255,255));
  width: 60%;
  height: 100%;
}

.content {
  clip-path: polygon(0 0, 100% 0, 70% 100%, 0% 100%);
  background: rgba(255,0,255, 0.5);
  height: 200px;
}

.background {
  z-index: 0;
  position: absolute;
  top: 20px;
  left: 0;
  background: black;
  width: 500px;
  height: 90px;
  margin-top: 50px;
}

<div >
  <div >
    <!-- Blue -->
    <div >
      <!-- Pink -->
    </div>
  </div>
  <div >
    <!-- Black -->
  </div>
</div>

A couple of aspects are not quite right:

1. The drop-shadow is visible through the pink, it should just be outside of the element.
2. The blue should extend to the left-hand edge.
3. The blue is transparent when I have not assigned it to be, it seems to be related to the child element's background being transparent.

Are there any CSS masters who can figure out a way to do this? The HTML can change if needed.

CodePudding user response：

a box-shadow with skew transformation can do the job here. I am using pseudo-element for the sake of the demo but you can replace them with real elements

.box {
  margin: 10px 0;
  display: flex;
  position: relative;
}

.box::before {
  content: "";
  position: absolute;
  inset: 30% 0;
  background: black;
}

.box::after {
  content: "";
  height: 200px;
  width: 50%;
  transform-origin: top;
  transform: skew(-20deg);
  background: rgb(255 0 255/80%);
  box-shadow: 25px 25px 0 blue;
}

body {
  margin: 0
}

<div >

</div>