Update app.py

app.py

@@ -53,16 +53,32 @@ def _matrix_payload(np_mat: np.ndarray, labels: Optional[List[str]] = None):
 
 def _plot_heatmap(D: np.ndarray, labels: Optional[List[str]] = None) -> np.ndarray:
     """Return an RGB image (as numpy array) of the heatmap."""
-    fig, ax = plt.subplots(figsize=(6, 5), dpi=160)
+    # Set dark mode style
+    plt.style.use('dark_background')
+    
+    fig, ax = plt.subplots(figsize=(6, 5), dpi=160, facecolor='#1e1e1e')
+    ax.set_facecolor('#1e1e1e')
+    
     im = ax.imshow(D, cmap="viridis")
-    plt.colorbar(im, ax=ax, fraction=0.046, pad=0.04)
+    cbar = plt.colorbar(im, ax=ax, fraction=0.046, pad=0.04)
+    cbar.ax.tick_params(colors='white')  # Light colorbar labels
+    
     if labels and len(labels) == D.shape[0]:
         ax.set_xticks(np.arange(len(labels)))
         ax.set_yticks(np.arange(len(labels)))
-        ax.set_xticklabels(labels, rotation=60, ha="right", fontsize=8)
-        ax.set_yticklabels(labels, fontsize=8)
-    ax.set_title("Dataset Distance Matrix")
+        ax.set_xticklabels(labels, rotation=60, ha="right", fontsize=8, color='white')
+        ax.set_yticklabels(labels, fontsize=8, color='white')
+    
+    ax.set_title("Dataset Distance Matrix", color='white')
     ax.grid(False)
+    
+    # Set axis colors to light
+    ax.spines['bottom'].set_color('white')
+    ax.spines['top'].set_color('white')
+    ax.spines['right'].set_color('white')
+    ax.spines['left'].set_color('white')
+    ax.tick_params(colors='white', which='both')
+    
     fig.tight_layout()
 
     # Render and grab RGBA buffer (works across Matplotlib versions)