在 Firefox 31 中，此代码仅显示为一列而不是多列：
#wrapper {
width: 90%;
max-width: 1100px;
min-width: 800px;
margin: 50px auto;
}
#columns {
-webkit-column-count: 3;
-webkit-column-gap: 10px;
-webkit-column-fill: auto;
-moz-column-count: 3;
-moz-column-gap: 10px;
-moz-column-fill: auto;
column-count: 3;
column-gap: 15px;
column-fill: auto;
}
.pin {
display: inline-block;
background: #FEFEFE;
border: 2px solid #FAFAFA;
margin: 0 2px 15px;
-webkit-column-break-inside: avoid;
-moz-column-break-inside: avoid;
column-break-inside: avoid;
padding: 15px;
padding-bottom: 5px;
background: -webkit-linear-gradient(45deg, #FFF, #F9F9F9);
}
.pin img {
width: 100%;
border-bottom: 1px solid #ccc;
padding-bottom: 15px;
margin-bottom: 5px;
}
.pin p {
color: #333;
margin: 0;
}
@media (min-width: 960px) {
#columns {
-webkit-column-count: 4;
-moz-column-count: 4;
column-count: 4;
}
}
@media (min-width: 1100px) {
#columns {
-webkit-column-count: 5;
-moz-column-count: 5;
column-count: 5;
}
}<div id="wrapper">
<div id="columns">
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/2/2v3VhAp.png" />
<p>
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed feugiat consectetur pellentesque. Nam ac elit risus,
ac blandit dui. Duis rutrum porta tortor ut convallis.
Duis rutrum porta tortor ut convallis.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/1/1swi3Qy.png" />
<p>
Donec a fermentum nisi.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/6/6f3nXse.png" />
<p>
Nullam eget lectus augue. Donec eu sem sit amet ligula
faucibus suscipit. Suspendisse rutrum turpis quis nunc
convallis quis aliquam mauris suscipit.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/8/8kEc1hS.png" />
<p>
Nullam eget lectus augue. Donec eu sem sit amet ligula
faucibus suscipit. Suspendisse rutrum turpis quis nunc
convallis quis aliquam mauris suscipit.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/1/1swi3Qy.png" />
<p>
Donec a fermentum nisi. Integer dolor est, commodo ut
sagittis vitae, egestas at augue.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/6/6f3nXse.png" />
<p>
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed feugiat consectetur pellentesque. Nam ac elit risus,
ac blandit dui. Duis rutrum porta tortor ut convallis.
Duis rutrum porta tortor ut convallis.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/2/2v3VhAp.png" />
<p>
Nullam eget lectus augue. Donec eu sem sit amet ligula
faucibus suscipit. Suspendisse rutrum turpis quis nunc
convallis quis aliquam mauris suscipit.
Duis rutrum porta tortor ut convallis.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/1/1swi3Qy.png" />
<p>
Nullam eget lectus augue.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/8/8kEc1hS.png" />
<p>
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed feugiat consectetur pellentesque.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/2/2v3VhAp.png" />
<p>
Donec a fermentum nisi. Integer dolor est, commodo ut
sagittis vitae, egestas at augue. Suspendisse id nulla
ac urna vestibulum mattis. Duis rutrum porta tortor ut convallis.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/1/1swi3Qy.png" />
<p>
Donec a fermentum nisi. Integer dolor est, commodo ut
sagittis vitae, egestas at augue. Suspendisse id nulla
ac urna vestibulum mattis.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/6/6f3nXse.png" />
<p>
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed feugiat consectetur pellentesque. Nam ac elit risus,
ac blandit dui. Duis rutrum porta tortor ut convallis.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/2/2v3VhAp.png" />
<p>
Donec a fermentum nisi. Integer dolor est, commodo ut
sagittis vitae, egestas at augue. Suspendisse id nulla
ac urna vestibulum mattis.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/1/1swi3Qy.png" />
<p>
Donec a fermentum nisi. Integer dolor est, commodo ut
sagittis vitae, egestas at augue. Suspendisse id nulla
ac urna vestibulum mattis.
</p>
</div>
<div class="pin">
<img src="http://cssdeck.com/uploads/media/items/6/6f3nXse.png" />
<p>
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed feugiat consectetur pellentesque. Nam ac elit risus,
ac blandit dui. Duis rutrum porta tortor ut convallis.
</p>
</div>
</div>
</div>这是为什么？