html {
    background: url("bg.png") no-repeat center center fixed;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
    min-height: 100vh;
}
body {
    display: grid;
    min-height: 95vh;
    margin: 0;
    place-items: center center;
    align-items: center;
    justify-content: center;
    background-color: transparent;
}

.game-over {
    animation-duration: 2s;
    animation-iteration-count: 2;
}

.blue {
    padding-top: 50px;
    animation-delay: 5s;
    animation-iteration-count: 1;
}
.playagain {
    display: block;
    max-width: 50%;
    padding-top: 100px;
    animation-delay: 8s;
    animation-iteration-count: 1;
}

.content {
    display: grid;
    text-align: center;
    align-items: center;
    place-items: center center;
    justify-content: center;
}

img {
    display: block;
    max-width: 95%;
    height: auto;
    margin: 0 auto;
}