@property --colour-blood-red {
    syntax: '<color>';
    inherits: false;
    initial-value: #300;
}

@keyframes bg-breathing{
    from {
        --colour-blood-red:#370007;
    }
    to {
        --colour-blood-red:#200;
    }
}

body.thepump-original {
    background-image: linear-gradient(#100 20%, #012 25%, #012 36%, var(--colour-blood-red) 52%, #100 70%, #000 83%);
    animation:bg-breathing 7s ease-in-out infinite alternate;
}