diff --git a/Makefile b/Makefile
index 27fc053..ac08e41 100644
--- a/Makefile
+++ b/Makefile
@@ -49,13 +49,13 @@ assemble: $(BUILD_DIR)/.exists
 	done
 	@echo "  all.md"
 	@cat $(HEADER) $(INTRO) $(foreach t,$(TERMINS),$(SLIDES_DIR)/$(t).md) $(OUTRO) > $(BUILD_DIR)/all.md
-	@cp -r assets $(BUILD_DIR)/ 2>/dev/null || true
+	@cp -r $(SLIDES_DIR)/assets $(BUILD_DIR)/ 2>/dev/null || true
 
-# Development server - serves build/ with file picker
-dev: assemble
-	@echo "Starting dev server..."
+# Development server - serves slides/ directly with HMR
+dev:
+	@echo "Starting dev server with HMR..."
 	@echo "Open: http://localhost:1312"
-	PORT=1312 npx @marp-team/marp-cli --server $(BUILD_DIR)/
+	PORT=1312 npx @marp-team/marp-cli --server $(SLIDES_DIR)/
 
 # Watch for changes
 watch: assemble