how to align div horizontally code example

Example 1: css center

/* this will center all children within the parent element. */
.parent {
  display: flex;
  justify-content: center; /* horizontal */
  align-items: center; /* vertical */
}

Example 2: vertical align css

.container{
  display: table;
}

.div-inside-container{
  display: table-cell;
  vertical-align: middle;
}