CSS going-around content flow

The following solution does not use JavaScript and somewhat scalable. I use display: flex so that I could use the order property.

The basic idea is to assign order: 1 to the last item, order: 2 to the second last item and so on. The first half of the items have order: -1 and a pseudo element having order: 0 is used as a separator. The tricky part is where you figure out the "first half" of items:

.demo {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  background: #EEE;
}
.demo > * {
  margin: .5em;
  width: 4em;
  height: 4em;
  background: #0CF;
}

/*
 * the example work for a list of 20 elements
 * for additional elements extend the repeating selectors
 */

/* all items ordered backwards */

.demo > :nth-last-child(1)  { order: 1; }
.demo > :nth-last-child(2)  { order: 2; }
.demo > :nth-last-child(3)  { order: 3; }
.demo > :nth-last-child(4)  { order: 4; }
.demo > :nth-last-child(5)  { order: 5; }
.demo > :nth-last-child(6)  { order: 6; }
.demo > :nth-last-child(7)  { order: 7; }
.demo > :nth-last-child(8)  { order: 8; }
.demo > :nth-last-child(9)  { order: 9; }
.demo > :nth-last-child(10) { order: 10; }

/* first half items are source ordered */

.demo> :nth-child(-n+0):nth-last-child(n+1),
.demo> :nth-child(-n+1):nth-last-child(n+2),
.demo> :nth-child(-n+2):nth-last-child(n+3),
.demo> :nth-child(-n+3):nth-last-child(n+4),
.demo> :nth-child(-n+4):nth-last-child(n+5),
.demo> :nth-child(-n+5):nth-last-child(n+6),
.demo> :nth-child(-n+6):nth-last-child(n+7),
.demo> :nth-child(-n+7):nth-last-child(n+8),
.demo> :nth-child(-n+8):nth-last-child(n+9),
.demo> :nth-child(-n+9):nth-last-child(n+10),
.demo> :nth-child(-n+10):nth-last-child(n+11) {
  order: -1;
}

/* the separator uses flex-basis trick and ordered between the two halves */

.demo::after {
  content: "";
  flex-basis: 100%;
  order: 0;
}
<div class="demo">
  <div>1</div>
  <div>2</div>
  <div>3</div>
  <div>4</div>
  <div>5</div>
  <div>6</div>
  <div>7</div>
  <div>8</div>
  <div>9</div>
  <div>10</div>
</div>

For two column layout, specify flex-direction: column; height: 25em on the parent (height must be fixed).


I was able to do this with Flexbox and a bit of JavaScript (I was unable to do it with CSS alone):

var reverseBoxes = function () {

  var flexItems = document.querySelectorAll(".child"),
      flexItemsCount = flexItems.length,
      reverseAt = flexItems.length / 2,
      breakPoint = 480;

  for (var i = reverseAt; i < flexItemsCount; i++) {
    flexItems[i].style.order = flexItemsCount - i;
  }

  for (var j = 0; j < flexItemsCount; j++) {
    if (window.innerWidth > breakPoint) {
      flexItems[j].style.width = (100 / flexItemsCount) * 2 - 2 + "%";
      flexItems[j].style.height = "auto";
    } else {
      flexItems[j].style.height = (100 / flexItemsCount) * 2 - 2 + "%";
      flexItems[j].style.width = "auto";
    }
  }

}

reverseBoxes();
window.addEventListener("resize", reverseBoxes);
body {
  font-family: Arial, sans-serif;
  font-size: 18px;
  margin: 0;
  padding: 0;
}

.parent {
  display: flex;
  flex-wrap: wrap;
  list-style-type: none;
  padding: 0;
  height: 100vh;
}

.child {
  margin: 1%;
  text-align: center;
  background: #069;
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
}

@media only screen and (max-width: 480px) {
  .parent {
    flex-direction: column;
  }
  .child {
    width: 48%;
  }
}
<div class="parent">
  <div class="child">A</div>
  <div class="child">B</div>
  <div class="child">C</div>
  <div class="child">D</div>
  <div class="child">E</div>
  <div class="child">F</div>
  <div class="child">G</div>
  <div class="child">H</div>
  <div class="child">I</div>
  <div class="child">J</div>
</div>

Is it what you ware looking for?


It's clear that a pure scalable CSS solution doesn't actually exist in order to achieve such thing so you will need some scripting to dynamically adjust some properties in order to obtain the needed layout.

If we suppose that all the elements have the same width we can identify the number of element per row and apply styles to the elements depending on the row.

Here is a basic example based on a code of this previous answer: https://stackoverflow.com/a/49046973/8620333

//total number of element
var n_t = $('.item').length;
//full width of element with margin
var w = $('.item').outerWidth(true);
//width of container without padding
var w_c = $('.grid').width();
//nb element per row
var nb = Math.min(parseInt(w_c / w),n_t);
console.log(nb);
$('.item:nth-child(1n+'+(nb+1)+')').addClass('right');
$('.item:nth-child(1n+'+(2*nb+1)+')').removeClass('right');
$('.item:nth-child(1n+'+(3*nb+1)+')').addClass('right');
$('.item:nth-child(1n+'+(4*nb+1)+')').removeClass('right');

window.addEventListener('resize', function(event){
   //only the width of container will change
   w_c = $('.grid').width();
   nb = Math.min(parseInt(w_c / w),n_t);
   $('.item').removeClass('right');   
  $('.item:nth-child(1n+'+(nb+1)+')').addClass('right');
  $('.item:nth-child(1n+'+(2*nb+1)+')').removeClass('right');
  $('.item:nth-child(1n+'+(3*nb+1)+')').addClass('right');
  $('.item:nth-child(1n+'+(4*nb+1)+')').removeClass('right');
});
.grid {
  background-color: #ddd;
  padding: 10px 0 0 10px;
  overflow:hidden;
}

.item {
  width: 80px;
  height: 80px;
  float:left;
  clear:right;
  background-color: red;
  margin: 0 10px 10px 0;
}
.item.right {
  float:right;
  clear:left;
  background:blue;
}

body {
  margin:0;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="grid">
  <div class="item">A</div>
  <div class="item">B</div>
  <div class="item">C</div>
  <div class="item">D</div>
  <div class="item">E</div>
  <div class="item">F</div>
  <div class="item">G</div>
  <div class="item">H</div>
  <div class="item">I</div>
  <div class="item">J</div>
  <div class="item">K</div>
  <div class="item">L</div>
  <div class="item">M</div>
  <div class="item">N</div>
  <div class="item">O</div>
  <div class="item">P</div>
</div>

This example isn't a perfect one as we have issue with alignment but the idea is to apply floating property to rows by alternating rows. I only considered 4 rows but we can easily make it dynamic using a loop like below:

//total number of element
var n_t = $('.item').length;
//full width of element with margin
var w = $('.item').outerWidth(true);
//width of container without padding
var w_c = $('.grid').width();
//nb element per row
var nb = Math.min(parseInt(w_c / w),n_t);
for(var i=1;i<n_t;i++) {
if(i%2==1)
   $('.item:nth-child(1n+'+(i*nb+1)+')').addClass('right');
else
   $('.item:nth-child(1n+'+(i*nb+1)+')').removeClass('right');
}

window.addEventListener('resize', function(event){
   //only the width of container will change
   w_c = $('.grid').width();
   nb = Math.min(parseInt(w_c / w),n_t);
   $('.item').removeClass('right');
  for(var i=1;i<n_t;i++) {
    if(i%2==1)
      $('.item:nth-child(1n+'+(i*nb+1)+')').addClass('right');
    else
      $('.item:nth-child(1n+'+(i*nb+1)+')').removeClass('right');
  }
});
.grid {
  background-color: #ddd;
  padding: 10px 0 0 10px;
  overflow:hidden;
}

.item {
  width: 80px;
  height: 80px;
  float:left;
  clear:right;
  background-color: red;
  margin: 0 10px 10px 0;
}
.item.right {
  float:right;
  clear:left;
  background:blue;
}

body {
  margin:0;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="grid">
  <div class="item">A</div>
  <div class="item">B</div>
  <div class="item">C</div>
  <div class="item">D</div>
  <div class="item">E</div>
  <div class="item">F</div>
  <div class="item">G</div>
  <div class="item">H</div>
  <div class="item">I</div>
  <div class="item">J</div>
  <div class="item">K</div>
  <div class="item">L</div>
  <div class="item">M</div>
  <div class="item">N</div>
  <div class="item">O</div>
  <div class="item">P</div>
</div>

To have better alignment, we can consider the use of CSS grid or flexbox but in this case we will need to adjust the order property of the elements.

With CSS grid:

//total number of element
var n_t = $('.item').length;
//full width of element with margin
var w = $('.item').outerWidth(true);
//width of container without padding
var w_c = $('.grid').width();
//nb element per row
var nb = Math.min(parseInt(w_c / w), n_t);
//nb rows
var nr = n_t / nb;
//order of element
var or = 0;

for (var i = 0; i < nr; i++) {
  if (i % 2 == 0)
    for (var j = 0; j < nb; j++) {
      $('.item').eq(nb * i + j).css('order', or++);
    }
  else
    for (var j = 0; j < nb; j++) {
      $('.item').eq(nb * i + (nb - j - 1)).css('order', or++);
    }
}

window.addEventListener('resize', function(event) {
  //only the width of container will change
  w_c = $('.grid').width();
  nb = Math.min(parseInt(w_c / w), n_t);
  nr = n_t / nb;
  or = 0;
  for (var i = 0; i < nr; i++) {
    if (i % 2 == 0)
      for (var j = 0; j < nb; j++) {
        $('.item').eq(nb * i + j).css('order', or++);
      }
    else
      for (var j = 0; j < nb; j++) {
        $('.item').eq(nb * i + (nb - j - 1)).css('order', or++);
      }
  }
});
.grid {
  background-color: #ddd;
  display: grid;
  grid-template-columns: repeat( auto-fit, 80px);
  padding: 10px 0 0 10px;
}

.item {
  height: 80px;
  background-color: red;
  font-size: 30px;
  color: #fff;
  font-weight: bold;
  margin: 0 10px 10px 0;
}

body {
  margin: 0;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="grid">
  <div class="item">A</div>
  <div class="item">B</div>
  <div class="item">C</div>
  <div class="item">D</div>
  <div class="item">E</div>
  <div class="item">F</div>
  <div class="item">G</div>
  <div class="item">H</div>
  <div class="item">I</div>
  <div class="item">J</div>
  <div class="item">K</div>
  <div class="item">L</div>
  <div class="item">M</div>
  <div class="item">N</div>
  <div class="item">O</div>
  <div class="item">P</div>
</div>

This method allow a better alignment but the last row isn't always good.

We can correct the last row by adjusting the last elements usgin grid-column like below:

//total number of element
var n_t = $('.item').length;
//full width of element with margin
var w = $('.item').outerWidth(true);
//width of container without padding
var w_c = $('.grid').width();
//nb element per row
var nb = Math.min(parseInt(w_c / w), n_t);
//nb rows
var nr = Math.ceil(n_t / nb);
//order of element
var or = 0;

for (var i = 0; i < nr; i++) {
  if (i % 2 == 0)
    for (var j = 0; j < nb; j++) {
      $('.item').eq(nb * i + j).css('order', or++);
    }
  else
    for (var j = 0; j < nb; j++) {
      $('.item').eq(nb * i + (nb - j - 1)).css('order', or++);
      /*fix the last row*/
      if (i == (nr - 1)) {
        $('.item').eq(nb * i + j).css('grid-column', " " + (nb - j));
      }
    }
}

window.addEventListener('resize', function(event) {
  //only the width of container will change
  w_c = $('.grid').width();
  nb = Math.min(parseInt(w_c / w), n_t);
  nr = Math.ceil(n_t / nb);
  $('.item').css('grid-column', 'auto');
  or = 0;
  for (var i = 0; i < nr; i++) {
    if (i % 2 == 0)
      for (var j = 0; j < nb; j++) {
        $('.item').eq(nb * i + j).css('order', or++);
      }
    else
      for (var j = 0; j < nb; j++) {
        $('.item').eq(nb * i + (nb - j - 1)).css('order', or++);
        /*fix the last row*/
        if (i == nr - 1) {
          $('.item').eq(nb * i + j).css('grid-column', " " + (nb - j));
        }
      }
  }
});
.grid {
  background-color: #ddd;
  display: grid;
  grid-template-columns: repeat( auto-fit, 80px);
  grid-auto-flow: dense;
  padding: 10px 0 0 10px;
}

.item {
  height: 80px;
  background-color: red;
  font-size: 30px;
  color: #fff;
  font-weight: bold;
  margin: 0 10px 10px 0;
}

body {
  margin: 0;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="grid">
  <div class="item">A</div>
  <div class="item">B</div>
  <div class="item">C</div>
  <div class="item">D</div>
  <div class="item">E</div>
  <div class="item">F</div>
  <div class="item">G</div>
  <div class="item">H</div>
  <div class="item">I</div>
  <div class="item">J</div>
  <div class="item">K</div>
  <div class="item">L</div>
  <div class="item">M</div>
  <div class="item">N</div>
  <div class="item">O</div>
  <div class="item">P</div>
</div>

Flexbox can be more suitable for the second case (the column direction). We simply do the same thing as previously considering columns instead of rows:

//total number of element
var n_t = $('.item').length;
//full height of element with margin
var w = $('.item').outerHeight(true);
//height of container without padding
var w_c = $('.grid').height();
//nb element per row
var nb = Math.min(parseInt(w_c / w), n_t);
//nb rows
var nr = n_t / nb;
//order of element
var or = 0;

for (var i = 0; i < nr; i++) {
  if (i % 2 == 0)
    for (var j = 0; j < nb; j++) {
      $('.item').eq(nb * i + j).css('order', or++);
    }
  else
    for (var j = 0; j < nb; j++) {
      $('.item').eq(nb * i + (nb - j - 1)).css('order', or++);
    }
}

window.addEventListener('resize', function(event) {
  //only the width of container will change
  w_c = $('.grid').height();
  nb = Math.min(parseInt(w_c / w), n_t);
  nr = n_t / nb;
  or = 0;
  for (var i = 0; i < nr; i++) {
    if (i % 2 == 0)
      for (var j = 0; j < nb; j++) {
        $('.item').eq(nb * i + j).css('order', or++);
      }
    else
      for (var j = 0; j < nb; j++) {
        $('.item').eq(nb * i + (nb - j - 1)).css('order', or++);
      }
  }
});
.grid {
  display: flex;
  height:100vh;
  flex-direction:column;
  flex-wrap:wrap;
  align-items:flex-start;
  align-content:flex-start;
  padding-top: 10px;
  padding-left:10px;
  box-sizing:border-box;
}

.item {
  height: 80px;
  width:80px;
  background-color: red;
  font-size: 30px;
  color: #fff;
  font-weight: bold;
  margin: 0 10px 10px 0;
}

body {
  margin: 0;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="grid">
  <div class="item">A</div>
  <div class="item">B</div>
  <div class="item">C</div>
  <div class="item">D</div>
  <div class="item">E</div>
  <div class="item">F</div>
  <div class="item">G</div>
  <div class="item">H</div>
  <div class="item">I</div>
  <div class="item">J</div>
  <div class="item">K</div>
  <div class="item">L</div>
  <div class="item">M</div>
  <div class="item">N</div>
  <div class="item">O</div>
  <div class="item">P</div>
</div>

There is also an alignment issue in some cases with the last column that we can fix by adjust margin:

//total number of element
var n_t = $('.item').length;
//full height of element with margin
var w = $('.item').outerHeight(true);
//height of container without padding
var w_c = $('.grid').height();
//nb element per row
var nb = Math.min(parseInt(w_c / w), n_t);
//nb rows
var nr = Math.ceil(n_t / nb);
//order of element
var or = 0;
for (var i = 0; i < nr; i++) {
  if (i % 2 == 0)
    for (var j = 0; j < nb; j++) {
      $('.item').eq(nb * i + j).css('order', or++);
    }
  else {
    for (var j = 0; j < nb; j++) {
      $('.item').eq(nb * i + (nb - j - 1)).css('order', or++);
    }
    if (i == (nr - 1)) {
      /*we add margin+height of non-existing element*/
      $('.item:last').css('margin-top', ((nb * nr - n_t) * (80 + 10)) + "px")
    }
  }
}

window.addEventListener('resize', function(event) {
  //only the width of container will change
  w_c = $('.grid').height();
  nb = Math.min(parseInt(w_c / w), n_t);
  nr = Math.ceil(n_t / nb);
  or = 0;
  $('.item').css('margin-top', 0); /*reset the margin*/
  for (var i = 0; i < nr; i++) {
    if (i % 2 == 0)
      for (var j = 0; j < nb; j++) {
        $('.item').eq(nb * i + j).css('order', or++);
      }
    else {
      for (var j = 0; j < nb; j++) {
        $('.item').eq(nb * i + (nb - j - 1)).css('order', or++);
      }
      if (i == (nr - 1)) {
        /*we add margin+height of non-existing element*/
        $('.item:last').css('margin-top', ((nb * nr - n_t) * (80 + 10)) + "px")
      }
    }
  }
});
.grid {
  display: flex;
  height: 100vh;
  flex-direction: column;
  flex-wrap: wrap;
  align-items: flex-start;
  align-content: flex-start;
  padding-top: 10px;
  padding-left: 10px;
  box-sizing: border-box;
}

.item {
  height: 80px;
  width: 80px;
  background-color: red;
  font-size: 30px;
  color: #fff;
  font-weight: bold;
  margin: 0 10px 10px 0;
}

body {
  margin: 0;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="grid">
  <div class="item">A</div>
  <div class="item">B</div>
  <div class="item">C</div>
  <div class="item">D</div>
  <div class="item">E</div>
  <div class="item">F</div>
  <div class="item">G</div>
  <div class="item">H</div>
  <div class="item">I</div>
  <div class="item">J</div>
  <div class="item">K</div>
  <div class="item">L</div>
  <div class="item">M</div>
  <div class="item">N</div>
  <div class="item">O</div>
  <div class="item">P</div>
</div>