body {
    position: fixed;
    display: inline-block;
    width: 100%;
    height: 100%;
}

main {
    position: relative;
    display: inline-block;
    width: 500px;
    height: 500px;
    background-color: coral;
}

:is(.snake, img) {
    position: absolute;
    display: inline-block;
    width: 50px;
    height: 50px;
}

img {
    background-color: coral;
}

.snake {
    background-color: lightgreen;
}

.hidden {
    opacity: 0;
}