问IE11中的css悬停不返回到未悬停样式

EN

.social-icons li a { display:block;}

.social-icons li a { display:inline-block;}

<ul id="social">
    <li>
        <a href="#" class="fb">
            <div class="social-icon"></div>
        </a>
    </li>
</ul>

#social
{
    position: absolute;
    right: 0;
}
li
{
    list-style: none;
}
.social-icon
{
    height: 40px;
    width: 120px;
    background: red;
}
.fb
{
    margin-top: 5px;
    margin-right: -75px; 
    display: block;
}
.fb:hover
{
    margin-right: 0px;
    -webkit-transition: .5s;
    -o-transition: .5s;
    -moz-transition: .5s;
    transition: .5s;
}