Generate utility classes or theme variants with loops — powerful but easy to bloat CSS; generate only what you need.
Going deeper
In production Sass work, @if, @for, @each matters when documents, stylesheets, or apps must stay maintainable across teams and releases—not only in isolated demos.
Common pitfalls
Watch for copy-paste configs, skipping validation or tests, and mixing concerns (structure vs presentation vs behavior) in one layer.
Practice
- Apply one technique from this lesson in the playground.
- Write one interview-style sentence explaining when you would use @if, @for, @each on a real project.