If anyone has trouble getting this to work on Windows this did the trick for me.
watchers: [
# Start the esbuild watcher by calling Esbuild.install_and_run(:default, args)
esbuild: {Esbuild, :install_and_run, [:default, ~w(--sourcemap=inline --watch)]},
node: [
"node_modules/tailwindcss/lib/cli.js",
"--input=css/app.css",
"--output=../priv/static/assets/app.css",
"--postcss",
"--watch",
cd: Path.expand("../assets", __DIR__)
]
]
