style.css

.wp-caption-text {
    font-size: 18px;
    font-size: 1.8rem;
    font-weight: 700;
    margin: 0;
    text-align: left;
    background: #fff;
    border-bottom: 1px solid #ddd;
    padding: 17px 0 17px 24px;
    line-height: 120%;
    color: #111;
    position: relative;
}

.wp-caption-text:before {
    font: 14px/1 FontAwesome;
    content: "\f030";
    margin-right: 10px;
    color: #0093C2;
    display: inline-block;
}