<div class="arrow"></div>
.arrow {
     position: relative;
     content: '';
     width: 30px;
     height: 30px;
     background: #d01137;
     border-radius: 50%;
}
.arrow::after {
     position: absolute;
     content: '';
     width: 0;
     height: 0;
     border: solid 8px transparent;
     border-left: solid 10px #fff;
     top: 50%;
     left: 11px;
     margin-top: -8px;
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.