Magento2.4.2 multi website setup not working

Question

I have upgraded the Magento version from 2.3.3 to M2.4.2 now the main example.com working fine and example.com/wholesale | example.com/retail not working. I have copied .htaccess from pub to these subfolders but it's not working. following errors are throwing:

Refused to apply style from '<URL>' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.

Here is index.php

$params[\Magento\Store\Model\StoreManager::PARAM_RUN_CODE] = 'wholesale'; 
$params[\Magento\Store\Model\StoreManager::PARAM_RUN_TYPE] = 'website';
$bootstrap = \Magento\Framework\App\Bootstrap::create(BP, $params);
/** @var \Magento\Framework\App\Http $app */
$app = $bootstrap->createApplication('Magento\Framework\App\Http');
$bootstrap->run($app);

Answer 1

Magento 2.4.2 now enforces the best practice of serving all content from magento_root/pub.

Most sites won't notice this change because of the rewrites in the 2.4.2 version of magento_root/.htaccess

https://github.com/magento/magento2/commit/640cad53009b291334234ccd61ab79f256b43da2

RewriteEngine on
RewriteCond %{REQUEST_URI} !^/pub/
RewriteCond %{REQUEST_URI} !^/setup/
RewriteCond %{REQUEST_URI} !^/update/
RewriteCond %{REQUEST_URI} !^/dev/
RewriteRule .* /pub/$0 [L]
DirectoryIndex index.php

These rewrites will have no effect on stores served from sub folders which will now be broken.

The simplest way to load one or more stores via url sub folders is to create the sub folder in magento_root/pub and symlink to the static pub folders/files.

For example

https://shop.com/wholesale/

mkdir magento_root/pub/wholesale
cd magento_root/pub/wholesale
ln -s ../media media
ln -s ../static static
ln -s ../../pub pub
ln -s ../.htaccess .htaccess
ln -s ../health_check.php health_check.php

magento_root/pub/wholesale/index.php

<?php
$params[\Magento\Store\Model\StoreManager::PARAM_RUN_CODE] = 'wholesale'; 
$params[\Magento\Store\Model\StoreManager::PARAM_RUN_TYPE] = 'website';
$bootstrap = \Magento\Framework\App\Bootstrap::create(BP, $params);
/** @var \Magento\Framework\App\Http $app */
$app = $bootstrap->createApplication('Magento\Framework\App\Http');
$bootstrap->run($app);