Add stroke_opacity style, fix #321

pygal/css/style.css

@@ -93,6 +93,7 @@
 
 {{ id }}.reactive {
   fill-opacity: {{ style.opacity }};
+  stroke-opacity: {{ style.stroke_opacity }};
 }
 
 {{ id }}.ci {
@@ -102,6 +103,7 @@
 {{ id }}.reactive.active,
 {{ id }}.active .reactive {
   fill-opacity: {{ style.opacity_hover }};
+  stroke-opacity: {{ style.stroke_opacity_hover }};
   stroke-width: 4;
 }
 
@@ -164,6 +166,7 @@
 
 {{ id }}.map-element .reactive {
   fill-opacity: inherit;
+  stroke-opacity: inherit;
 }
 
 {{ colors }}

pygal/style.py

@@ -65,6 +65,10 @@ class Style(object):
 
     opacity = '.7'
     opacity_hover = '.8'
+
+    stroke_opacity = '.8'
+    stroke_opacity_hover = '.9'
+
     transition = '150ms'
     colors = (
         '#F44336',  # 0