body:not(.wp-admin)::before {
    content: "";
    position: fixed;
    left: 0;
    top: 0;
    width: 1.25rem;
    height: 100vh;
    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='20' height='960' viewBox='0 0 20 960' fill='none'><path d='M0 529.23H20V960H0V529.23Z' fill='white'/><rect y='209.23' width='20' height='320' fill='%23A3D8F6'/><rect width='20' height='209.231' fill='%23013476'/></svg>");
    background-repeat: no-repeat;
    background-size: cover;
    z-index: 9999;
}

@media (max-width: 800px), (max-width: 600px) {
    body:not(.wp-admin)::before {
        width: 0.75rem; !important
        z-index: 9999;
    }
}