ul li {
position: relative;
}
ul li::after {
display: block;
content: '';
position: absolute;
top: .5em;
left: -1em;
width: 8px;
height: 3px;
border-left: 2px solid #3498db;
border-bottom: 2px solid #3498db;
-webkit-transform: rotate(-45deg);
transform: rotate(-45deg);
}