Moving Icon to Bottom when Accordion Open

To move icon to bottom when accordion is opened, like this

You can use this code to Website Tools > Custom CSS.

[data-is-open="true"] .accordion-icon-container {
    position: absolute;
    bottom: 10px;
    right: 0;
    z-index: 999999;
}

Result

If you want to apply this on specific accordion, first you need to find Accordion ID.
In my example, it is: #block-yui_3_17_2_1_1722935850341_3420

Next, use this CSS code

#block-yui_3_17_2_1_1722935850341_3420 [data-is-open="true"] .accordion-icon-container {
    position: absolute;
    bottom: 10px;
    right: 0;
    z-index: 999999;
}

Or if you want to do this on desktop only, use this CSS code

@media screen and (min-width:768px) {
  [data-is-open="true"] .accordion-icon-container {
    position: absolute;
    bottom: 10px;
    right: 0;
    z-index: 999999;
  }}

If mobile only, use this CSS code

@media screen and (max-width:767px) {
  [data-is-open="true"] .accordion-icon-container {
    position: absolute;
    bottom: 10px;
    right: 0;
    z-index: 999999;
  }}