There's a debate about whether Sass is necessary, given that CSS itself has allowed for nested coding structures. However, I think it's useful for module development, so it's knowledge that's good to have. The key might be not getting stuck on building the compilation environment rather than the syntax. ■ Product Overview "Sass Textbook for Web Creators, Revised 2nd Edition: CSS Preprocessor Essential for Web Design" - Author: Takashi Hirasawa, So Morita - Publisher: Impress - Softcover: 296 pages - Price: 2,400 yen + tax ■ Condition - There are dog-eared pages, but otherwise, there are no noticeable stains or scratches. - The 3rd edition is the latest, but you can grasp the essence of Sass with this book.