.my-flex, .my-center, .my-middle, .my-left, .my-top, .my-right, .my-bottom, .my-stretch {
  display: flex;
}

.my-center {
  justify-content: center;
}

.my-middle {
  align-items: center;
}

.my-left {
  justify-content: flex-start;
}

.my-top {
  align-items: flex-start;
}

.my-right {
  justify-content: flex-end;
}

.my-bottom {
  align-items: flex-end;
}

.my-stretch {
  align-items: stretch;
}