I'm trying to make a custom notification badge with CSS/SCSS. I want to insert content from html attribute (data-badge) as in the HTML code, but when I call it on the CSS it shows nothing.
HTML
<ul id="nav-mobile" class="right hide-on-med-and-down">
    <li>
        <a href="#" class="nav-icons"><i class="material-icons" data-badge="4">info</i></a>
    </li>
    <li>
        <a href="#" class="nav-icons"><i class="material-icons">email</i></a>
    </li>
    <li>
        <a href="#" class="dropdown-button" data-activates="dropdown-user">
            <div class="chip">
                <img src="/images/personal.png" alt="Contact Person">
                                Jane Doe
                                <i class="material-icons right">arrow_drop_down</i>
            </div>
        </a>
    </li>
</ul>
SCSS
a.nav-icons {
    max-height: 60px !important;
    i.material-icons {
    max-height: 60px;
    font-size: 2rem;
    line-height: 60px;
        &[data-badge] {
            content: attr(data-badge);
            position: relative;
            color: #fff;
                &::after {
                    content: attr(data-badge);
                    position: absolute;
                    background: red;
                    border-radius: 50%;
                    display: block;
                    padding: 0.3em;
                    color: black;
                    font-size: 12px;
                    max-height: 20px;
                    max-width: auto;
                    right: -10px;
                    top: 8px;
                  }
             }
        }
}
Or, please see this fiddle below.
https://jsfiddle.net/5gxudefb/3/
Thank you in advance