flex align content in middle code example

Example 1: flexbox align center vertically

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

.Aligner-item {
  max-width: 50%;
}

.Aligner-item--top {
  align-self: flex-start;
}

.Aligner-item--bottom {
  align-self: flex-end;
}

Example 2: flexbox align right and left

.primary-nav {
    display:-webkit-flex;
    display:flex;
    list-style-type:none;
    padding:0;
    justify-content:flex-end;
}

.left {
    margin-right:auto;
}