/* https://codepen.io/collection/XPjvPP/ */
/* Render items as columns */
.container {
display: flex;
flex-flow: column wrap;
}
/* Re-order items into rows */
.item:nth-child(3n+1) { order: 1; }
.item:nth-child(3n+2) { order: 2; }
.item:nth-child(3n) { order: 3; }
/* Force new columns */
.container::before,
.container::after {
content: "";
flex-basis: 100%;
width: 0;
order: 2;
}