.l-demo-main {
  display: flex;
  flex-direction: column;
  flex-wrap: nowrap; }
  .l-demo-main > div:nth-child(1) {
    height: 80px; }
  .l-demo-main > div:nth-child(2) {
    display: flex;
    flex-direction: row;
    flex-wrap: nowrap;
    height: calc(100vh - 160px); }
    .l-demo-main > div:nth-child(2) > div:nth-child(1) {
      width: 20vw; }
    .l-demo-main > div:nth-child(2) > div:nth-child(2) {
      width: 60vw; }
    .l-demo-main > div:nth-child(2) > div:nth-child(3) {
      width: 20vw; }
  .l-demo-main > div:nth-child(3) {
    height: 80px; }