Breaking to a new line with inline-block?

Remove all br tags and use display: table.

.text span {
   background: rgba(165, 220, 79, 0.8);
   display: table;
   padding: 7px 10px;
   color: white;
}
.fullscreen .large { font-size: 80px }

Explanation: The table wraps the width of its content by default without setting a width, but is still a block level element. You can get the same behavior by setting a width to other block-level elements:

<span style="display:block;border:1px solid red;width:100px;">Like a default table.</span>
<code>null</code>

Notice the <code> element doesn't flow inline with the <span> like it would normally. Check it out with the computed styles in your dev tools. You'll see pseudo margin to the right of the <span>. Anyway, this is the same as the table, but the table has the added benefit of always forming to the width of its content.

use float: left; and clear: left;

http://jsfiddle.net/rtM6J/

.text span {
   background: rgba(165, 220, 79, 0.8);
   float: left;
   clear: left;
   padding: 7px 10px;
   color: #fff;
}