css怎么让图案上下浮动

@keyframes movepoint {

    25% {

        top: 16px

    }

    100%,

     {

        top: 50px

    }

}

.shade-button-point {

    display: inline-block;

    position: absolute;

    top: 50px;

    left: 30%;

    animation: movepoint 2s infinite;

    -webkit-animation: movepoint 2s infinite;

}