fix native checkbox indeterminate icon; closes #386

docs/docs/resources/changelog.md

@@ -19,6 +19,7 @@ During the alpha period, things might break! We take breaking changes very serio
 - Fixed a bug that caused dropdowns inside button groups to show with a vertical misalignment
 - Revert `<wa-dialog>` structure and CSS to fix clipped content in dialogs (WA-A #123) and light dismiss in iOS Safari (WA-A #201)
 - Fixed a bug in `<wa-progress>` that prevented Safari from animation progress changes
+- Fixed the missing indeterminate icon in native checkbox styles
 
 ### Enhancements
 

src/styles/native/checkbox.css

@@ -38,6 +38,16 @@ input[type='checkbox']:where(:not(:host *)) {
     height: 100%;
     width: 100%;
   }
+
+  &:indeterminate::after {
+    background-color: currentColor;
+    content: '';
+    mask: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" height="16" width="14" viewBox="0 0 448 512"><path d="M431 256c0 17.7-14.3 32-32 32H49c-17.7 0-32-14.3-32-32s14.3-32 32-32h350c17.7 0 32 14.3 32 32z"/></svg>')
+      center no-repeat;
+    position: absolute;
+    height: 100%;
+    width: 100%;
+  }
 }
 
 input[type='checkbox']:where(:not(:host *)),