Testing browser support of CSS features with feature queries

CSS feature queries, facilitated by the @supports rule, allow developers to test browser support for specific CSS features, ensuring consistent functionality across different browsers. This capability is crucial for maintaining cross-browser compatibility, as not all CSS properties are supported by every browser. Feature queries can test single or multiple CSS features, using logical operators like "and" and "or" to handle various scenarios, including vendor prefixes. They also support negation for detecting unsupported features, providing the opportunity to implement fallbacks, which are alternative CSS solutions that maintain design consistency even on browsers with limited support. For instance, if a browser doesn't support the "display: grid" feature, a developer can use Flexbox as a fallback. This technique helps developers cater to all users, regardless of their browser, by building a basic version of the design with universal features and enhancing it with feature queries for more advanced capabilities. Additionally, tools like LogRocket offer resources for monitoring and optimizing client-side performance, ensuring a seamless user experience across different devices and browsers.