Temporarily block users from editing in the #WordPress Dashboard #php

functions.php

// Maintenance mode function
add_action('admin_head', 'block_admin_editing_style');
    
function block_admin_editing_style() {
        echo "<style>
        	#wpwrap{
        		display:none!important;
              	} 
             </style>
             <script>
             	jQuery(document).ready(function($){
             		$('body').prepend('<h1 style=\'line-height: 1.2em;text-align: center;padding: 0 10vw;\'>Site temporarily blocked from editing due to maintenance. Please contact [email protected] if you have questions or concerns. Thank you kindly for your understanding.</h1>');
             	});
             </script>";
}