JSFiddle - React, Tailwind, and code Playground

HTML

<button class="quicklinks-button">Show/Hide</button>

<div class="quick-links-container">
    <div class="left-corner"></div>
    QUICK LINKS
</div>

CSS

body{
    background-color: #444;
}
.quick-links-container{
    right: 20px;
    background-color: white;
    height: 500px;
    width: 200px;
    position: absolute;
    box-shadow:5px 1px 6px rgba(0,0,0,.2);
}

.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 0px 6px rgba(0,0,0,.2);
    z-index: -1;
    position: relative;
    left:-10px;
    top: 23px;
}

JavaScript

$('.quicklinks-button').click(
    function(){
        $('.quick-links-container').toggle(1000);
    }
);