Using conditional classes in Vue enables dynamic styling that responds to component state, user interactions, and data changes for creating interactive and responsive user interfaces. As the creator of CoreUI, a widely used open-source UI library, I’ve implemented conditional classes in thousands of Vue components for theme switching, state visualization, interactive elements, and responsive layouts across enterprise applications. From my expertise, the most effective approach is to use the v-bind:class directive with object and array syntax. This method provides reactive styling, excellent performance, and clean template syntax while maintaining separation of concerns between logic and presentation.