.accordion-button::after{
    content: " " !important; 
    /* using an image as background for the arrow head */
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%234B5563'%3e%3cpath fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/%3e%3c/svg%3e") !important;
}
/* add the 180 deg transformation */
.accordion-button:not(.collapsed)::after{
    transform: rotate(180deg) !important;
}
/* update the color background to white */
.accordion-item {
    border: none !important;
    background-color: var(--bs-white);
}