<div id="membrane" style="display: none position: fixed; right: 0px; bottom: 0px; width: 100%; height:100%; background: grey; opacity: 0.5; z-index: 9500;" onclick="display_message('');"></div>

<div id="welcome" style="display: none; position: fixed; left: calc(50%); top: calc(50%); transform: translate(-50%, -50%); z-index: 10000; background: rgb(255, 255, 255); border-radius: 3px; box-shadow: rgba(0, 0, 0, 0.247059) 0px 1px 5px; padding: 10px 20px;"></div>