CSS Layout - Align an element Horizontal & Vertical center

alignments.css

/* HTML */

<div class="container">
  <div class="child"></div>
<div>

/* Basic Style  */

.container {
  width: 500px;
  height: 500px;
  background: #ccc;
}

.child {
  background: red;
  width: 100px;
  height: 100px;
}

/* Different ways to make an element horizontal & vertical center */

/* Way 1 - Using position: absolute;  */

.container {
  position: relative;
}

.child {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  top: 0;
  margin: auto;
}

/* Way 2 - Using Flexbox */

.container {
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Way 3 - Using CSS Grid */

.container {
  display: grid;
  place-items: center;
}

/* Way 4 - Using position: absolute; transform  */

.container {
  position: relative;
}

.child {
  position: absolute;
  transform: translate(-50%, -50%);
  top: 50%;
  left: 50%;
}

/* Way 5 - Using display: table & table-cell  */

.container {
  display: table;
}

.child {
  background: red;
  display: table-cell;
  vertical-align: middle;
  text-align: center;
}