RainbowKit's CSS doesn't get bundled in production, because the way they're exposing it is with a sideEffect. Webpack's side effects are basically an infinite black hole, as denoted by [[ https://github.com/webpack/webpack/issues/6571 | this issue ]] that's been open for 4.5 years. . more context/explanation on [[ https://phab.comm.dev/D5224 | this stack overflow answer ]]