Hide trello first board

CorsMiddleware.php

<?php

declare(strict_types=1);

namespace App\Middleware;

use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Server\MiddlewareInterface;
use Psr\Http\Server\RequestHandlerInterface;

/**
 * Cors middleware
 */
class CorsMiddleware implements MiddlewareInterface
{
    /**
     * Process method.
     *
     * @param \Psr\Http\Message\ServerRequestInterface $request The request.
     * @param \Psr\Http\Server\RequestHandlerInterface $handler The request handler.
     * @return \Psr\Http\Message\ResponseInterface A response.
     */
    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
    {

        $response = $handler->handle($request);

        if ($request->getHeader('Origin')) {
            $response = $response
                ->withHeader('Access-Control-Allow-Origin', '*')
                ->withHeader('Access-Control-Allow-Headers', '*');
            if (strtoupper($request->getMethod()) === 'OPTIONS') {
                $response = $response
                    ->withStatus(200, __('Say cheese!'));
            }
        }

        return $response;
    }
}

trellojs.js

// Here You can type your custom JavaScript...
$('#board .js-list .list-cards').first().hide();
$('#board .js-list').first().hover(function() {
  $('#board .js-list .list-cards').first().show();
});
$('#board .js-list').first().mouseleave(function() {
  $('#board .js-list .list-cards').first().hide();
});