Z-Index Internet Explorer

Internet Explorer is going complete bananas on it's z-indexes

HTML

<div class="container">
    <div class="content__container">
        <p class="__align-to-bottom __right" onclick="alert(this.tagName)">text <span class="__icon">f</span></p>
        <a href="#" class="__link" onclick="alert(this.tagName)"><span>text</span></a>
    </div>
</div>

CSS

.container{
    width: 100px;
    height: 100px;
    border: 1px solid black;
}

.content__container {
    position: relative;
    overflow: hidden;
    width: 100%;
    height: 100%;
}

.__align-to-bottom {
    position: absolute !important;
    bottom: 0;
    left: 0;
}

.__align-to-bottom.__right {
    left: auto;
    right: 0;
}

a.__link {
    position: absolute !important;
    display: block;
    width: 100%;
    height: 100%;
    left: 0;
    top: 0;
}

a.__link span{
    display: none;
}