Add light mode

epaint/src/shadow.rs

@@ -22,14 +22,22 @@ impl Shadow {
         }
     }
 
-    /// Windows
-    pub fn big() -> Self {
+    /// Subtle and nice on dark backgrounds
+    pub fn big_dark() -> Self {
         Self {
             extrusion: 32.0,
             color: Color32::from_black_alpha(96),
         }
     }
 
+    /// Subtle and nice on white backgrounds
+    pub fn big_light() -> Self {
+        Self {
+            extrusion: 32.0,
+            color: Color32::from_black_alpha(40),
+        }
+    }
+
     pub fn tessellate(&self, rect: emath::Rect, corner_radius: f32) -> Mesh {
         // tessellator.clip_rect = clip_rect; // TODO: culling