Define <br> by CSS means?

Let's say we have this markup:

<div>
   <span>1</span>
   <span>2</span>
   <span>3</span>
   <span>4</span>
   <span>5</span>
   <span>6</span>
</div>

and the desire to see these spans broken into two lines:
  123
  456

with div style defined as:

div { max-width: max-content; border:1px solid; }

so its width will be set set to max of widths "123" and "456".

Of course we can use <br> in markup between 3 and 4 but it is not CSS-ish.

Something like this:

  div>span:nth-child(3) { line-break:after; }

probably?

-- 
Andrew Fedoniouk.

http://terrainformatica.com