header+div.wp-block-group {
    position: relative;
    overflow: hidden;
    background: none !important;
}

header+div.wp-block-group::before {
    content: '';
    position: absolute;
    top: -100%;
    left: -100%;
    width: 300%;
    height: 300%;
    background: var(--wp--preset--gradient--primary);
    animation: rotateGradient infinite 3s linear;
    z-index: -1;
}

@keyframes rotateGradient {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}