Cascading Style Sheets Performance Questions

Focuses on writing and organizing Cascading Style Sheets for fast rendering and maintainability. Core areas include understanding browser rendering costs such as repaints and reflows, minimizing layout thrashing, selector efficiency and avoiding excessive specificity, modular CSS architecture and methodologies such as block element modifier naming conventions, structuring styles to reduce cascade complexity and deep nesting, strategies for reducing file size and unused styles, critical path CSS and progressive rendering, stylesheet delivery and caching, tooling and build optimizations including minification and tree shaking, and diagnosing performance with audits and metrics. Interviewers evaluate practical techniques, trade offs between maintainability and performance, and experience applying optimizations in real projects.