Horizontal masonry layout with flexbox CSS only [duplicate]

Question

I'm trying to create a horizontal masonry layout using only CSS and flexbox. The problem I'm having is there are vertical gaps between the elements, without using align-left: stretch; is it possible to close the gaps?

.card-container {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap; 
  align-items: flex-start;
}


.card {
  width: 25%;
  flex: 1 0 auto;
}

full codepen here

Answer 1

Here is one option using wrapped columns, but it requires a fixed height.

.card-container {
  display: flex;
  flex-flow: column wrap;
  height:100vh;
  align-items: center;
  background-color: #888;
}

A better option for CSS masonry layout is to use columns, an example is on this blog post http://w3bits.com/css-masonry/

.masonry { /* Masonry container */
    -moz-column-count: 4;
    -webkit-column-count: 4;
    column-count: 4;
    -moz-column-gap: 1em;
    -webkit-column-gap: 1em;
    column-gap: 1em;
}

.item { /* Masonry bricks or child elements */
    background-color: #eee;
    display: inline-block;
    margin: 0 0 1em;
    width: 100%;
}

Answer 2

Flex box wrap wraps the overflowing elements to a new row. This new row has, just like the previous row, the height of the highest flex child in it. It will not let the elements in the row go outside that rows boundaries.

So unfortunately, no you cannot close the vertical gaps with flexbox.