#board {
    width: 400px;
    height: 510px;
    border: 4px solid #333;
    margin: auto;
    position: relative;
}

.blocks {
    position: absolute;
    width: 145px;
    height: 50px;
    animation-fill-mode: forwards;
    border-radius: 5px;
}

.hideNow { 
    visibility: hidden;
}