body {
    margin: 0;
    background: url(youkai.jpg);
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center center;
}

#awoo {
    width: 100%;
    height: 100%;
    cursor: pointer;
    background: url(momiji.svg);
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center bottom -50px;
}

.wan {
    animation-name: wan;
    animation-duration: 0.2s;
    animation-timing-function: ease-in-out;
}

@keyframes wan {
    0% {
        background-position: center bottom -50px;
    }
    50% {
        background-position: center bottom 0;
    }
    100% {
        background-position: center bottom -50px;
    }
}