Is there possible to implement multisite ?

[bachvtuan]

Sharing same media files and login credentials but separate theme content, static pages, menu, etc.
Do you have any thought on this ?

[LukeTowers]

There is no one size fits all multisite solution, but in your specific case if you want to share everything except for themes then you can just use the domain driven environment configuration in order to set a different active theme per hostname: https://wintercms.com/docs/setup/configuration#domain-environment.

Basically you'd set the following in config/environment.php:

<?php

return [
    'hosts' => [
        'sitea.website.tld' => 'sitea',
        'siteb.website.tld' => 'siteb',
    ]
];

then in config/sitea/cms.php you'd set the following:

<?php

return [
    'activeTheme' => 'sitea',
];

and in config/siteb/cms.php you'd set the following:

<?php

return [
    'activeTheme' => 'siteb',
];