#header #nextcloud .logo {
    display: inline-flex;
    background-image: url("http://erba.education/wp-content/uploads/2023/02/cropped-logo.png");
    background-repeat: no-repeat;
    background-size: contain;
    background-position: center;
    width: 72px;
    position: absolute;
    left: 12px; /*'left' вместо устаревшего свойства */
    top: 1px;
    bottom: 1px;
    filter: var(--image-logoheader-custom, var(--background-image-invert-if-bright));
}