.arrow_box_left {
    position: relative;
    background: #ffffff;
    border: 4px solid #f50000;
}

.arrow_box_left:after,
.arrow_box_left:before {
    right: 100%;
    top: 50%;
    border: solid transparent;
    content: " ";
    height: 0;
    width: 0;
    position: absolute;
    pointer-events: none;
}

.arrow_box_left:after {
    border-color: rgba(255, 255, 255, 0);
    border-right-color: #ffffff;
    border-width: 12px;
    margin-top: -12px;
}

.arrow_box_left:before {
    border-color: rgba(245, 0, 0, 0);
    border-right-color: #f50000;
    border-width: 18px;
    margin-top: -18px;
}