Q:

Extra Space Between inline-block DIV Elements

I am creating a fluid layout using the CSS column layout module and am seeing unexpected results when 2 or more elements are in the same 'row' of a column.   A 3 to 4 px gap will appear between the elements.   I've tested in IE11, FireFox 24, Chrome 31, and Safari 5.1.7 and they all exhibit the same behavior. 
<div class="tile-container">
    <div class="tile-large">1</div>
    <div class="tile-wide">2</div>
    <div class="tile-small">3</div>
    <div class="tile-small">4</div>
    <div class="tile-small">5</div>
    <div class="tile-small">6</div>
    <div class="tile-wide">7</div>
    <div class="tile-large">8</div>
</div>

.tile-container {
    -moz-column-width: 250px;
    -webkit-column-width: 250px;
    column-width: 250px;
    column-fill: auto;
    height: 502px;
    background-color: gray;
}

.tile-large {
    width: 250px;
    height: 250px;
    -webkit-column-break-inside: avoid;
    break-inside: avoid;
    display: inline-block;
    background-color: green;
}

.tile-wide {
    width: 250px;
    height: 125px;
    -webkit-column-break-inside: avoid;
    break-inside: avoid;
    display: inline-block;
    background-color: blue;
}

.tile-small {
    width: 125px;
    height: 125px;
    -webkit-column-break-inside: avoid;
    break-inside: avoid;
    display: inline-block;
    background-color: red;
}

I don't want to start using negative margins to close the gap as I want to introduce drag/drop behavior.   Float left will remove the gap, but that introduces another set of issues.  Oddly enough, when I use jQueryUI sortable, after the drop event and jQueryUI arranges the elements, the gap is no longer there.  

A:

You need to comment out the white space between the elements, like so:
<div class="tile-container">
       <div class="tile-large">1</div><!--
    --><div class="tile-wide">2</div><!--
    --><div class="tile-small">3</div><!--
    --><div class="tile-small">4</div><!--
    --><div class="tile-small">5</div><!--
    --><div class="tile-small">6</div><!--
    --><div class="tile-wide">7</div><!--
    --><div class="tile-large">8</div>
</div>

DEMO: http://jsfiddle.net/P7cbA/11/
Another way is to put the elements in the HTML in one line without any spaces between them, but this reduces the code readability:
<div class="tile-container">
       <div class="tile-large">1</div><div class="tile-wide">2</div><div class="tile-small">3</div><div class="tile-small">4</div><div class="tile-small">5</div><div class="tile-small">6</div><div class="tile-wide">7</div><div class="tile-large">8</div>
</div>

