diff --git a/build.sh b/build.sh
index 9183b50..253af13 100755
--- a/build.sh
+++ b/build.sh
@@ -10,19 +10,13 @@ if ! [ -f core.tgz ]; then
 	curl -o core.tgz https://registry.npmjs.org/@blueprintjs/core/-/core-3.30.0.tgz
 fi
 
+# cleanup
 mkdir -p static
-
 rm -fR static/.gitignore static/*
 
-# decompress the tar file but extract the `.css` files only
-# find every file in the nested directories and move it behind `./static`
-# finally remove every directory behind `./static`
-bsdtar xvzf core.tgz -C static \*.css &&
-	find ./static -mindepth 2 -type f -print -exec mv {} ./static \; &&
-	find ./static -mindepth 1 -type d -print -exec rm -rf {} \;
-
+# build
+bsdtar xOf core.tgz package/lib/css/blueprint.css > static/blueprint.css
 wasm-pack build --no-typescript --target web --out-name wasm --out-dir ./static "${options[@]}" "$@"
-
 rc=$?
 
 rm -fR static/{.gitignore,package.json}