Google Drive is more of an end consumer product, similar to Apple’s iCloud. You really shouldn’t use it as a way to link files especially HTML and CSS into your website. Instead you should be using object storage.
At DigitalOcean we have Spaces, which is our object storage platform and you can use that to host your CSS and then link to it from your HTML.
In the future we will also be releasing the ability to use DigitalOcean spaces as a static site - so that you can just upload HTML, CSS, etc and it would be served as a static site for you making the whole process much easier.