JSFiddle - React, Tailwind, and code Playground

HTML

<div class="roomblock_content">
    <div class="roomblock_col1">
        <div class="roomblock_pool_box">
            <span class="roomblock_pool_title"> Pool </span>

            <ul class="roomblock_slots">
                <li>
                    <div class="con_user prepaid_con">8 </div>
                </li>
                <li>
                    <div class="con_user prepaid_con">15 </div>
                </li>
            </ul>
        </div>
    </div>
</div>

CSS

.roomblock_content {
    border:1px solid red;
}

JavaScript

$("div.con_user").draggable({ 
        delay: 100,
        revert: true,
        scroll: false,
        containment: ".roomblock_content",
        start: function( event, ui) {
            $(this).css("z-index", "200");
        },
        stop: function( event, ui) {
            $(this).css("z-index","50");
        }
    });