1.wrap {
2 display: flex;
3 flex-wrap: wrap;
4 flex-direction: column; /* NEW */
5 height: 100px; /* NEW */
6 justify-content: space-between; /* NEW */
7}
8.elem1 {
9 width: 20%;
10 flex-basis: 100%; /* NEW */
11 border: 1px solid red;
12}
13.elem2,
14.elem3 {
15 width: 75%;
16 flex-basis: 40%; /* NEW */
17 border: 1px solid red;
18}