*{
    padding: 0;
    margin: 0;
}
#game{
    width: 310px;
    height: 510px;
    border: 5px solid white;
    margin: auto;
    box-sizing: border-box;
    z-index: 3;
}
#character{
    width: 100px;
    height: 100px;
    background: url(tati.png);
    position: relative;
    top: 300px;
    left: 0px;
}
#block{
    width: 100px;
    height: 100px;
    top: 500px;
    background: url(yagoda.png);
    position: relative;
    animation: slide 1s infinite linear;
}
@keyframes slide{
    0%{top:-100px};
    100%{top:500px};
}
#left, #right{
    width:50%;
    position: absolute;
    height: 500px;
}
#right{
    left: 50%;
}