I've been building an intranet at work using Sharepoint, and I've been trying to figure out how to have a larger search bar on modern web pages, like you could on classic pages with the Search Bar web part. I read that modern pages have no such equivalent web part, so I was wondering if instead I could create classic pages that use classic web parts on modern sites?
From your description, it seems that you want to use both the modern pages and classic pages in SharePoint Online.
If yes, I think you can achieve that via he following steps.
a. Navigate to a library.
b. Click Return to classic SharePoint>Settings>Site contents>Site Pages>New to create a classic page.
c. If you click Settings>Add a page, you can still create a modern page.
Could I create classic pages that use classic web parts on modern sites?
Unfortunately, it's not supported to add a classic web parts on modern pages!
These customizations are currently not supported for "modern" pages:
- Adding "classic" web parts on "modern" pages
- Custom CSS via AlternateCSSUrl web property
- Custom master pages (more extensive branding will be supported later using alternative options)
- Minimal Download Strategy (MDS)
- Modern pages inside of the Site Template package (Save site as a template)
For more details, check Customizing "modern" site pages