.spinner-overlay {
    position: fixed;
    top: 0; left: 0;
    width: 100vw; height: 100vh;
    background-color: rgba(46, 33, 17, 0.92); /* your deep brown, mostly opaque */
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 20000;
}

.reihax-logo-pulse {
    width: 140px;
    max-width: 60vw;    /* don't let it be too big on small screens */
    animation: logo-pulse 1.6s infinite alternate cubic-bezier(.4,0,.2,1);
    filter: brightness(1);
    transform: translateY(-50px);
}

@keyframes logo-pulse {
    0%   { filter: brightness(1); transform: scale(1);}
    100% { filter: brightness(0.6); transform: scale(1.09);}
}