Nested loops in LESS

NestedLESSLoops

.outer(@outer) when (@outer > 0) {
    (~".outer@{outer}") {
        color: red;
        .inner(@inner) when (@inner > 0) {
             font-size: @inner;
            .inner(@inner - 1);
        }
        .inner(0) {}
        .inner(@outer);
    }
    .outer(@outer - 1);
}
.outer(0) {}

// Gives you

.outer3 {
  color: red;
  font-size: 3;
  font-size: 2;
  font-size: 1;
}
.outer2 {
  color: red;
  font-size: 2;
  font-size: 1;
}
.outer1 {
  color: red;
  font-size: 1;
}