Worked on the JetBrains/kotlin-wrappers repository to deliver foundational cross-platform WebAssembly support for Kotlin CSS. Focused on build configuration and Kotlin Multiplatform, the work introduced a wasmJs target within the kotlin-css module, leveraging ExperimentalWasmDsl to enable compiling Kotlin CSS to WebAssembly JavaScript. This integration exposed wasmJs() as part of the Kotlin target suite, enhancing portability and runtime performance for CSS in WebAssembly environments. The approach aimed to reduce JavaScript bundle size and improve startup times across supported browsers. The implementation was completed using Gradle and Kotlin, with an emphasis on maintainable build processes and cross-platform compatibility.