Improve graph quality with custom CSS

modules/__init__.py

@@ -1,4 +1,5 @@
 import os
+from tempfile import NamedTemporaryFile
 
 from PIL import Image, ImageDraw
 
@@ -18,6 +19,35 @@ class Config:
             self.fnt_RI_path = "/usr/share/fonts/TTF/LinBiolinum_RIah.ttf"
             self.fnt_RB_path = "/usr/share/fonts/TTF/LinBiolinum_RBah.ttf"
 
+        self.css_overlay = NamedTemporaryFile()
+        with open(self.css_overlay.name, 'w') as f:
+            f.write('''
+{{ id }} .bound {
+    font-size: 0.9em;
+}
+{{ id }} .gauge path {
+    fill-opacity: 1 !important;
+}
+{{ id }} .series .line {
+    stroke-width: 2 !important;
+}
+{{ id }} .x .guides .line {
+    stroke-width: 0 !important;
+}
+{{ id }} .y .guides .line {
+    stroke: #555;
+    stroke-width: 0.7;
+}
+{{ id }} .y .guides .line.axis {
+    stroke: #000;
+    stroke-width: 1;
+}
+            ''')
+
+        import pygal
+        self.pygal_config = pygal.Config()
+        self.pygal_config.css.append('file://' + self.css_overlay.name)
+
         from pygal.style import Style
         self.pygal_custom_style = Style(
             background='white',