css how to align div horizontally code example

Example 1: how to align elements horizontally in css

.row {
  width: 100%;
  display: flex;
  flex-direction: row;
  justify-content: center;
}
.block {
  width: 100px;
}

Example 2: how to horizontal center a div in css

#inner {
  width: 50%;
  margin: 0 auto;
}