Display table centering

Vertically and horizontally centers a child element within its parent element, using display: table.

• Use display: table to make the .center element behave like a <table> element.
• Set height and width to 100% to make the element fill the available space within its parent element.
• Use display: table-cell on the child element to make it behave like a <td> elements.
• Use text-align: center and vertical-align: middle on the child element to center it horizontally and vertically.
• The outer parent (.container) must have a fixed width and height.

<div class="container">
  <div class="center"><span>Centered content</span></div>
</div>

.container {
  border: 1px solid #9C27B0;
  height: 250px;
  width: 250px;
}

.center {
  display: table;
  height: 100%;
  width: 100%;
}

.center > span {
  display: table-cell;
  text-align: center;
  vertical-align: middle;
}