css3 箭头上下跳动

.container .stepsItem.permit .permitStepItem .table .showTable {
    width: .37rem;
    margin: .20rem auto;
    position: absolute;
    bottom: 0;
    left: 50%;
    margin-left: -.18rem;
    -webkit-animation: opener .5s ease-in-out alternate infinite;
    animation: opener .5s ease-in-out alternate infinite;
    cursor: pointer;
    opacity: 0.5;
    -webkit-transition: opacity .2s ease-in-out, transform .5s ease-in-out .2s;
    transition: opacity .2s ease-in-out, transform .5s ease-in-out .2s;
}

@-webkit-keyframes opener {
    100% {
        bottom: .05rem;
    }
}

@keyframes opener {
    100% {
        bottom: .05rem;
    }
}