What specific steps should be taken to minimize Cumulative Layout Shift (CLS) on a mobile e-commerce site?

Minimizing Cumulative Layout Shift (CLS) on a mobile e-commerce site requires several specific steps to ensure a stable and user-friendly experience. CLS measures the unexpected shifting of page elements while the page is still loading. A high CLS score indicates a poor user experience and can negatively impact search rankings. First, always include size attributes (width and height) on images and video elements. This allows the browser to reserve the correct amount of space for these elements before they load, preventing layout shifts when the content appears. Second, reserve space for ad slots. If ads are dynamically injected into the page, pre-allocate the space they will occupy to avoid content reflowing when the ads load. Use placeholders or skeleton loaders. Third, avoid inserting new content above existing content, unless in response to a user interaction. Dynamically injecting content above existing content causes significant layout shifts and is disruptive to the user. Fourth, use the 'transform' CSS property for animations instead of properties that trigger layout. The 'transform' property allows for animations without causing the browser to recalculate layout, resulting in smoother transitions. Fifth, optimize font loading. Use 'font-display: swap' to display a fallback font while the custom font is loading, preventing text from shifting when the custom font becomes available. Sixth, test thoroughly using tools like Chrome DevTools and Lighthouse to identify and address any remaining CLS issues. Focus on real user data to understand the actual CLS experience for your mobile users.