Worked on the WebPlatformForEmbedded/WPEWebKit repository to enhance the stability and modernity of the WebInspectorUI by addressing a CSS compatibility issue. Focused on front-end development, the work involved replacing the deprecated :matches() pseudo-class with the modern :is() selector in the CSS, ensuring consistent UI behavior across browsers and preventing interface breakage when accessed over HTTP. This update aligned the codebase with current CSS standards and improved cross-browser accessibility. The solution was implemented using JavaScript and advanced CSS selectors, demonstrating attention to detail in maintaining compatibility and reducing the risk of UI regressions in the Web Inspector environment.