Dunning, D. (2014, October 27). We Are All Confident Idiots. Pacific Standard. https://psmag.com/social-justice/confident-idiots-92793
<div class="demo-arrow">Demo Arrow</div>
.demo-arrow {
display: inline-block;
position: relative;
background: #000;
color: #fff;
padding: 10px 20px;
width: 260px;
border-radius: 4px;
}
.demo-arrow:after {
position: absolute;
display: inline-block;
content: '';
left: 14px;
top: 100%;
width: 0;
height: 0;
border-top: 6px solid #000;
border-right: 6px solid transparent;
border-bottom: 0 solid transparent;
border-left: 6px solid transparent;
}