Browsing the Library
The Problems page, without any filters, allows you to browse the Stella library page by page. Clicking on a problem's Stella number will take you to a page showing the contents of that particular problem. The solution is hidden by default, but can be revealed by clicking the appropriate button.
You may also filter the problems by their tags or search by text. There are three types of tags: Problem Set, Course, and Topic. Each is set to "All" by default, but you may configure them to your liking using the dropdown menus. The text input allows you to search for a problem based on words contained in its title or its description. (Searching for a problem based on text in its solution is not supported.)
Clicking the "Apply" button will reload the page and show only those problems that match your query. Additionally, the links in the sidebar allow you to quickly filter by any single tag.