fix: install graphviz in Makefile, add light theme CSS override

Makefile

@@ -16,6 +16,16 @@ help: ## Show this help message
 	@echo ""
 
 install: ## Create venv and install dependencies
+	@echo "📦 Installing system dependencies (graphviz)..."
+	@if command -v apt-get >/dev/null 2>&1; then \
+		sudo apt-get update -qq && sudo apt-get install -y -qq graphviz; \
+	elif command -v brew >/dev/null 2>&1; then \
+		brew install graphviz; \
+	elif command -v yum >/dev/null 2>&1; then \
+		sudo yum install -y graphviz; \
+	else \
+		echo "⚠️  Please install graphviz manually"; \
+	fi
 	@echo "📦 Creating virtual environment..."
 	@$(PYTHON) -m venv $(VENV)
 	@$(VENV_PIP) install --upgrade pip

app.py

@@ -16,13 +16,34 @@ def main():
         neutral_hue=gr.themes.colors.gray,
     )
     
+    # Force light theme CSS
+    light_theme_css = """
+    .dark {
+        --body-background-fill: white !important;
+        --background-fill-primary: white !important;
+        --background-fill-secondary: #f7f7f7 !important;
+        --block-background-fill: white !important;
+        --body-text-color: #374151 !important;
+        --block-label-text-color: #374151 !important;
+        --block-title-text-color: #374151 !important;
+        --input-background-fill: white !important;
+        --input-background-fill-focus: white !important;
+        --border-color-primary: #e5e7eb !important;
+        --link-text-color: #ea580c !important;
+        --link-text-color-hover: #c2410c !important;
+        --button-primary-background-fill: #ea580c !important;
+        --button-primary-text-color: white !important;
+    }
+    """
+    combined_css = light_theme_css + (custom_css or "")
+    
     app.launch(
         share=False,
         server_name="0.0.0.0",
         server_port=7860,
         mcp_server=True,
         theme=theme,
-        css=custom_css,
+        css=combined_css,
         allowed_paths=[str(AUDIOS_DIR)],
     )