Add custom CSS without modifying the master page in SharePoint

Question

I am not allowed to use SharePoint Designer and i need to add a small piece of CSS for the top site and all subsites under the site collection!

Please help me to find appropraite way to apply a custom CSS on all subsites and site collection without using masterpage?

I am using SharePoint 2016

Answer 1

Add custom CSS without modifying the master page in SharePoint

If your site is a publishing site, so you can easily specify a CSS file to be used by the site collection and all sites that inherit from it.

Steps:

1. Open your Site Collection.

2. From the right settings gear, Click on Site Settings.

   

3. Below "Look and Feel", click on "Master Page".

   

Alternatively, Check this shortcut URL for this option http://SiteCollection/_layouts/15/ChangeSiteMasterPage.aspx

1. At "Alternate CSS URL", Specify a CSS file to be used by this site and all sites that inherit from it as shown below:

   

Note: If your site is a team site and you intend to activate the Publishing site feature you will miss some functionalities that you may need it, so it's highly recommended to check Activating Publishing Site Consideration before going to enable it.