text of div tag in the middle code example

Example 1: put text in center of a div

html, body {
    height: 100%;
}
.parent {
    width: 100%;
    height: 100%;
    display: table;
    text-align: center;
}
.parent > .child {
    display: table-cell;
    vertical-align: middle;
}

Example 2: how to set text to middle in div

.center {
  margin: auto;
  width: 50%;
  border: 3px solid green;
  padding: 10px;
}