How to rotate pseudo element css

Question

I want to recreate this icon using css pseudo elements (as a toggle indicator):

I have created the nececcary pseudo elements using ::after, ::before and tried to rotate them using transform: rotate(90deg).

How can I tell them to rotate around their own center? I have tried transform-origin: 50% 50%; which does not work. Right now, both pseudo elements got the same right: 10px; but they are not placed above each other, instead they are next to each other.

You can check this JS FIDDLE to illustrate the problem.

Answer 1

First you can use :before and :after pseudo elements and create shape like this DEMO

After that you can rotate parent element for 45deg and get desired result.

.el {
  margin: 50px;
  position: relative;
  transform: rotate(45deg);
  display: inline-block;
}
.el:before,
.el:after {
  content: '';
  width: 30px;
  height: 30px;
  position: absolute;
}
.el:before {
  border-top: 4px solid black;
  border-left: 4px solid black;
  top: -10px;
  left: -10px;
}
.el:after {
  border-bottom: 4px solid black;
  border-right: 4px solid black;
  top: 10px;
  left: 10px;
}

<div class="el"></div>

Update: You can also add some transition on :hover like this

.el {
  margin: 50px;
  position: relative;
  transform: rotate(45deg);
  display: inline-block;
  cursor: pointer;
}
.el:before,
.el:after {
  content: '';
  width: 30px;
  height: 30px;
  position: absolute;
  transition: all 0.3s ease-in;
}
.el:before {
  border-top: 4px solid black;
  border-left: 4px solid black;
  top: -10px;
  left: -10px;
}
.el:after {
  border-bottom: 4px solid black;
  border-right: 4px solid black;
  top: 10px;
  left: 10px;
}
.el:hover:before {
  top: -15px;
  left: -15px;
}
.el:hover:after {
  top: 15px;
  left: 15px;
}

<div class="el"></div>

Answer 2

transform-origin works fine, it's just that

a) 50% 50% (the object's center) is the default, and

b) you have to center the content of the box. That's a bit tricky because the icon you use doesn't require the full line height. Try adding

::before, ::after {
  padding-bottom: .17em;
}