JSFiddle - React, Tailwind, and code Playground

HTML

<div class="quicklinks-container">
    <button class="quicklinks-rollover" title="Quick Links">toggle</button>
</div>
<div class="quicklinks">
    <div class="left-corner"></div>
    <div class="quicklinks-title">QUICK LINKS</div>
    <div>
        <ul><a href="#">Item 0</a>

            <li><a href="#">Item 1</a>
            </li>
            <li><a href="#">Item 2</a>
            </li>
        </ul>
        <ul><a href="#">Item 3</a>

            <li><a href="#">Item 4</a>
            </li>
            <li><a href="#">Item 5</a>
            </li>
        </ul>
        <ul><a href="#">Item 6</a>
        </ul>
        <ul><a href="#">Item 7</a>
        </ul>
        <ul><a href="#">Item 8</a>
        </ul>
        <ul><a href="#">Item 9</a>
        </ul>
        <ul><a href="#">Item 10</a>

            <li><a href="#">Item 11</a>
            </li>
            <li><a href="#">Item 12</a>
            </li>
            <li><a href="#">Item 13</a>
            </li>
        </ul>
        <ul><a href="#">Item 14</a>

            <li><a href="#">Item 15</a>
            </li>
            <li><a href="#">Item 16</a>
            </li>
            <li><a href="#">Item 17</a>
            </li>
        </ul>
    </div>
</div>

CSS

body{background-color: #e0e0e0;}

.quicklinks-rollover{width:45px;height:45px;display:inline-block;background-color: cyan;border:none;cursor:pointer;padding:0;}
.quicklinks-rollover:hover{background-position:0 -44px;}

.quicklinks {
    color: #818285;
    padding: 20px;
    text-align: left;
    display: none;
    margin: 0 200px;
    background-color: white;
    height: auto;
    width: 225px;
    position: absolute;
    box-shadow:4px 1px 6px rgba(0, 0, 0, .2);
}
.quicklinks-title {
    display:block;
    font-family:'MuseoSlab500Regular', Arial, sans-serif;
    color:#FB8521;
    font-size:large;
    margin-top:-15px;
}
.left-corner {
    height: 25px;
    width: 25px;
    transform: rotate(45deg);
    -webkit-transform: rotate(45deg);
    -moz-transform: rotate(45deg);
    -o-transform: rotate(45deg);
    -ms-transform: rotate(45deg);
    background-color: white;
    box-shadow:10px 1px 6px rgba(0, 0, 0, .2);
    z-index: -1;
    position: relative;
    left:-30px;
    top: 5px;
}
.quicklinks div ul {
    margin: 10px 0 10px 10px;
    text-transform: capitalize;
    font-family:'Open Sans', sans-serif;
    font-size:.75em;
    font-weight: bold;
}
.quicklinks div ul a {
    color: #818285;
}
.quicklinks div ul a:hover {
    color: #818285;
    color: #fb8521;
}
.quicklinks div ul li {
    margin-left:20px;
    text-transform: capitalize;
    font-family:'Open Sans', sans-serif;
    font-size:.85em;
    font-weight: normal;
}

JavaScript

$('.quicklinks-rollover').click(function () {
    $('.quicklinks').toggle();
});
$(document).mouseup(function (e) {
    var container = $(".quicklinks");
    if (container.has(e.target).length === 0) {
        container.hide();
    }
});