.demo-content {
position: relative; 
background-color: #000;
color: #fff;
padding: 10px 20px;
border-radius: 6px;
} 

.demo-content::after {
position: absolute;
font-size: 2em;
color: #000;
content: "▾";
text-align: center;
top: 23px;
left: 20px;
}