If you want to apply some specific branding to your Site, without touching the master page, or site original CSS files, you can do this easily from the "Change the Look" page, which you can access it from the "ShortPoint Dashboard".

In this article, we will walk you through the process of having your external stylesheet applied to your Site, using ShortPoint Change the Look page.

Step 1: Upload your CSS file to Site Assets ( Optional )

because "Change the Look" needs a URL to your CSS file, then you need to upload your CSS file somewhere and have it accessible through a URL.
Your CSS file can be uploaded into your Office365 Site, your Website, or even a third party service.

But for the purpose of this demo, we will upload it to the same site.

Open the Settings Menu, and go to Site Contents

Then click on Site Assets Library

Click on the Upload button

An "Add a Document" dialog will appear, click on "Browse" to pick up your CSS file

Navigate to your desired CSS file to upload, and Click "Open" 

Then in the "Add a Document" dialog click "OK"

Now your CSS file is successfully uploaded into your Site Assets library.

Open "Menu Dialog" for your CSS file to Copy its URL

Step 2: Add your CSS file URL into Change the Look Page

To apply your CSS file into the current site, we need to go to the Change the Look page from the ShortPoint App Dashboard page.

To do this, open again the Settings Menu, and go to Site Contents

Then click on "ShortPoint Online" app

Which will open the "ShortPoint Online" App "Dashboard Page", Click on "Change the Look" page

And "Paste" the URL of the CSS file we copied previously into the "Custom CSS Link" field in the page, and hit "Save Changes"

That's it, now your CSS file is applied on the whole site.