diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..357fbba
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,25 @@
+# Build artifacts — must not be copied into the image.
+# Docker does NOT honor .gitignore, so these are listed explicitly.
+**/bin/
+**/obj/
+**/out/
+
+# IDE / tooling
+**/.vs/
+**/.vscode/
+**/.idea/
+**/*.user
+
+# Git / CI
+.git/
+.gitignore
+.github/
+
+# Docker
+Dockerfile
+.dockerignore
+docker-compose*.yml
+
+# Misc
+**/node_modules/
+**/*.md