T07b navigation places: nav item and group, navigation menu, back and forward history, table of contents with anchors, go to line; measuring canvases pinned to their parent

src/forms/color/gradient.rs

@@ -198,6 +198,8 @@ impl RenderOnce for GradientEditor {
                     |_, _, _, _| {},
                 )
                 .absolute()
+                .top_0()
+                .left_0()
                 .size_full(),
             )
             .on_mouse_down(MouseButton::Left, move |event, window, cx| {

src/forms/color/picker.rs

@@ -191,6 +191,8 @@ fn area(
                 |_, _, _, _| {},
             )
             .absolute()
+            .top_0()
+            .left_0()
             .size_full(),
         )
 }

src/forms/color/swatch.rs

@@ -58,6 +58,8 @@ pub(crate) fn checker(radius: Rems, cx: &App) -> impl IntoElement + use<> {
         },
     )
     .absolute()
+    .top_0()
+    .left_0()
     .size_full()
 }