CSS columns with left-right flow

Question

Let\'s say I have a div which will contain a set of elements (divs), which may have different heights, but all of them will have the same width.

I\'ve a

Answer 1

Here's a link on solution! Used only flex.

html

- var n = 0;
ul
  while n < 40
    li= n++
  li

css

ul {
    list-style: none;
    padding: 30px;
    background: #28285e;
    
    li {
        padding: 20px;
        margin: 6px;
        background: white;
        width: calc(50% - 52px);
        height: 100px;
        display: inline-block;
        border: {
            radius: 4px
        }
        
        &:nth-child(3n) {
            height: 40px;
        }
        
            
        &:nth-child(2n + 1) {
            height: 80px;
        }
        
        &:nth-child(even) {
            float: right;
        }
        
        &:nth-child(odd) {
            float: left;
        }
        
        &:last-child {
            clear: both;
            float: none;
        }
    }
}