.m-center {
    display: flex;
  -moz-box-align: center;
  align-items: center;
  -moz-box-pack: center;
  justify-content: center;
}

.m-stack {
    display: flex;
  flex-direction: column;
  -moz-box-align: stretch;
  align-items: stretch;
  -moz-box-pack: start;
  justify-content: flex-start;
  gap: 16px;
}