I apologize for any inconvenience caused by this oversight.
You said your logo is black. But in live site is white. In white background white logo is invisible. Clean the previously provided CSS code.
To better address the issue, could you kindly provide Joomla administrator access? This will enable me to thoroughly investigate the matter and provide you with a prompt resolution.
Before proceeding, I recommend that you create a backup of your site. You can use the Akeeba Backup extension for this purpose.
I appreciate your cooperation and will ensure to get back to you as soon as possible.
Best regards,