#changeTheme {
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
    width: 40px;
    height: 40px;
    display: block;
}

.btn-theme {
    background-image: var(--btn-theme-page-image) !important;
}

.btn-theme-dark {
    background-image: var(--btn-theme-page-image-dark);
}