.row, .col {
  display: flex;
}
.row {
  flex-direction: row;
}
.col {
  flex-direction: column;
}

.f-1 {
  flex:1;
}
.f-2 {
  flex: 2;
}
.f-3 {
  flex: 3;
}
.f-4 {
  flex: 4;
}

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

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