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Vertical Centering with `margin: auto;`

A Pen By Alan Crissey Pro

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CSS

            
              @mixin centered() {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  margin: auto;
}

body {
  background-color: #111;
}

.centered_element {
  background-color: #333;
  border: 2px dashed #999;
  width: 100px;
  height: 100px;
  @include centered();
}
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JS
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999px
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Console