Make an element as wide as the grandparent

Question

I have the following markup where #content is 80% wide and contains .slide elements. I want the slides to be as wide as their grandparent (i.e. bod

Answer 1

If your surrounding content can demand a different combination of positioning properties on their own, you could always go with the following.

body {
  margin: 0;
  font: medium monospace;
  background: lightgray;
}
#content {
  margin: auto;
  width: 80%;
  background: white;
}
#content:before,
#content:after {
  content: "";
  display: table;
}
.slide {
  height: 6em;
  background: indianred;
  width: 125%; /*100*(100/80)*/
  margin-left: 50%;
  transform: translateX(-50%);
}

  
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