To combine 2 Accordion Block into 1 Accordion on Mobile Squarespace, you can follow these.
#1. Use this free tool to find the ID of 2 Accordion Blocks.
In my example, we will have: #block-yui_3_17_2_1_1722935850341_3420, #block-yui_3_17_2_1_1723417893645_4683
#2. Use this code to Code Injection > Footer
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.0/jquery.min.js"></script>
<script>
jQuery(document).ready(function($) {
function run() {
if ($(window).width() <= 767) {
$('#block-yui_3_17_2_1_1723417893645_4683 li.accordion-item').appendTo('#block-yui_3_17_2_1_1722935850341_3420 ul.accordion-items-container');
} else {
}
}
run();
window.addEventListener('resize', run)
});
</script>
#3. Result
#4. To remove the bold line between 2 accordions, use this code to Custom CSS box
#block-yui_3_17_2_1_1722935850341_3420 li:nth-child(4) .accordion-divider.accordion-divider--top {
display: none !important;
}