Update css && run button location

app.py

@@ -134,7 +134,7 @@ if __name__ == "__main__":
     .gradio-container {background-color: black; color: white;}
     input, button, select, textarea, .gr-button, .gr-file, .gr-dropdown, .gr-image, .gr-file-upload {background-color: #333; color: white; border-color: white;}
     .gr-button, .gr-file, .gr-dropdown, .gr-image, .gr-file-upload {border: 1px solid white;}
-    .gr-image-preview {background-color: #333; border: 1px solid white;}
+    .gr-image-preview {background-color: #333; color: white; border: 1px solid white;}  /* Set image preview background to dark grey */
     """
 
     with gr.Blocks(css=css) as demo:
@@ -162,7 +162,7 @@ if __name__ == "__main__":
                 <ol style="list-style:none; padding-left:0;">
                     <li>1. Upload your `.h5ad` file</li>
                     <li>2. Select the species</li>
-                    <li>3. View the UMAP scatter plot</li>
+                    <li>3. Click "Run" to view the UMAP scatter plot</li>
                     <li>4. Download the UMAP coordinates</li>
                 </ol>
             </div>
@@ -178,14 +178,16 @@ if __name__ == "__main__":
         # Define Gradio inputs and outputs
         file_input = gr.File(label="Upload a .h5ad single cell gene expression file")
         species_input = gr.Dropdown(choices=["human", "mouse"], label="Select species")
+        run_button = gr.Button("Run")
         image_output = gr.Image(type="numpy", label="UMAP of UCE Embeddings")
         file_output = gr.File(label="Download embeddings")
     
         # Add the components and link to the function
-        gr.Button("Run").click(
+        run_button.click(
             fn=main, 
             inputs=[file_input, species_input], 
             outputs=[image_output, file_output]
         )
-    
+
     demo.launch()
+