Webkit-flex working while moz-flex is not - html

Question

So I have this CSS on a webpage, and when I test it in chrome and webkit-box-flex does exactly what it's meant to.
However, on firefox, it doesn't.
Please can someone look at my CSS and tell me what I need to change in order for this to work on both?
.buttonGroup
{
display: -webkit-box;
-webkit-box-orient: horizontal;
-webkit-box-pack:justify;
-webkit-box-flex: 1;
box-sizing: border-box;
display: -moz-box;
-moz-box-orient: horizontal;
-moz-box-pack:justify;
box-sizing: border-box;
}
.buttonGroup > li
{
display: block;
-webkit-box-flex: 1;
-moz-box-flex: 1;
box-flex: 1;
border: solid 1px #9a9a99;
border-left: none;
border-radius: 0px;
-webkit-border-radius: 0px;
text-align: center;
background: rgb(243,243,243); /* Old browsers */
background: -moz-linear-gradient(top, rgba(243,243,243,1) 0%, rgba(194,194,194,1) 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(243,243,243,1)), color-stop(100%,rgba(194,194,194,1))); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, rgba(243,243,243,1) 0%,rgba(194,194,194,1) 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(top, rgba(243,243,243,1) 0%,rgba(194,194,194,1) 100%); /* Opera 11.10+ */
background: -ms-linear-gradient(top, rgba(243,243,243,1) 0%,rgba(194,194,194,1) 100%); /* IE10+ */
background: linear-gradient(to bottom, rgba(243,243,243,1) 0%,rgba(194,194,194,1) 100%); /* W3C */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#f3f3f3', endColorstr='#c2c2c2',GradientType=0 ); /* IE6-9 */
color: #6b6b6b;
font-size: 16px;
padding: 10px;
}
http://jsfiddle.net/z6pc7wvt/
I have looked at -moz-box-flex is not flexing? Works with (Chrome/Webkit)
but his fix doesn't make sense to me.

Answer 1

It appears you are using the old prefixes and syntax. Firefox now supports flexbox natively without prefixes.
The current syntax would be:
.buttonGroup {
display: -webkit-box;
display: -webkit-flex;
display: -ms-flexbox;
display: flex;
box-sizing: border-box;
}
.buttonGroup > li {
-webkit-box-flex:1;
-webkit-flex:1;
-ms-flex:1;
flex:1;
}
$("ul.buttonGroup").click(function (event) {
$("li", this)
.removeClass("selected")
.filter(event.target)
.addClass("selected");
});
.buttonGroup {
display: -webkit-box;
display: -webkit-flex;
display: -ms-flexbox;
display: flex;
box-sizing: border-box;
}
.buttonGroup > li {
-webkit-box-flex:1;
-webkit-flex:1;
-ms-flex:1;
flex:1;
border: solid 1px #9a9a99;
border-left: none;
border-radius: 0px;
-webkit-border-radius: 0px;
text-align: center;
background: rgb(243, 243, 243);
/* Old browsers */
background: -moz-linear-gradient(top, rgba(243, 243, 243, 1) 0%, rgba(194, 194, 194, 1) 100%);
/* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, rgba(243, 243, 243, 1)), color-stop(100%, rgba(194, 194, 194, 1)));
/* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, rgba(243, 243, 243, 1) 0%, rgba(194, 194, 194, 1) 100%);
/* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(top, rgba(243, 243, 243, 1) 0%, rgba(194, 194, 194, 1) 100%);
/* Opera 11.10+ */
background: -ms-linear-gradient(top, rgba(243, 243, 243, 1) 0%, rgba(194, 194, 194, 1) 100%);
/* IE10+ */
background: linear-gradient(to bottom, rgba(243, 243, 243, 1) 0%, rgba(194, 194, 194, 1) 100%);
/* W3C */
filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#f3f3f3', endColorstr='#c2c2c2', GradientType=0);
/* IE6-9 */
color: #6b6b6b;
font-size: 16px;
padding: 10px;
}
.buttonGroup > li:first-child {
border-left: solid 1px #9a9a99;
-webkit-border-top-left-radius: 10px;
-webkit-border-bottom-left-radius: 10px;
border-top-left-radius: 10px;
border-bottom-left-radius: 10px;
}
.buttonGroup > li:last-child {
-webkit-border-top-right-radius: 10px;
-webkit-border-bottom-right-radius: 10px;
border-top-right-radius: 10px;
border-bottom-right-radius: 10px;
}
.buttonGroup > li.selected {
background: rgb(25, 58, 127);
/* Old browsers */
background: -moz-linear-gradient(top, rgba(25, 58, 127, 1) 0%, rgba(43, 86, 178, 1) 5%, rgba(97, 150, 241, 1) 100%);
/* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, rgba(25, 58, 127, 1)), color-stop(5%, rgba(43, 86, 178, 1)), color-stop(100%, rgba(97, 150, 241, 1)));
/* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, rgba(25, 58, 127, 1) 0%, rgba(43, 86, 178, 1) 5%, rgba(97, 150, 241, 1) 100%);
/* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(top, rgba(25, 58, 127, 1) 0%, rgba(43, 86, 178, 1) 5%, rgba(97, 150, 241, 1) 100%);
/* Opera 11.10+ */
background: -ms-linear-gradient(top, rgba(25, 58, 127, 1) 0%, rgba(43, 86, 178, 1) 5%, rgba(97, 150, 241, 1) 100%);
/* IE10+ */
background: linear-gradient(to bottom, rgba(25, 58, 127, 1) 0%, rgba(43, 86, 178, 1) 5%, rgba(97, 150, 241, 1) 100%);
/* W3C */
filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#193a7f', endColorstr='#6196f1', GradientType=0);
/* IE6-9 */
color: #fff;
border-color: #193a7f;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<ul class="buttonGroup">
<li class="selected">One</li>
<li>Two</li>
<li>Three</li>
</ul>
JSfiddle Demo
You might want to start using a prefixing tool like Autoprefixer or Prefix Free. They take all the hard work out of it.