.vou-box-list li:after {
    content: "";
    position: absolute;
    top: -20px;
    display: block;
    width: 10px;
    height: 100%;
    margin-top: 20px;
    background-size: 20px 10px;
    right: -3px;
    background-color: #ffffff;
    background-position: 100% 15%;
    background-image: linear-gradient(-45deg, #f0f0f0 25%, transparent 25%, transparent), linear-gradient(-135deg, #f0f0f0 25%, transparent 25%, transparent), linear-gradient(-45deg, transparent 75%, #f0f0f0 75%), linear-gradient(-135deg, transparent 75%, #f0f0f0 75%);
}