feat(ui): add configurable Iced themes

src/ui/popup/cycle_popup.rs

@@ -3,7 +3,7 @@
 //! adds that object to the current selection. Clicking outside dismisses it.
 
 use iced::widget::{button, column, container, mouse_area, opaque, text};
-use iced::{Background, Border, Color, Element, Fill, Length, Theme};
+use iced::{Element, Fill, Length};
 
 use crate::app::Message;
 
@@ -19,15 +19,7 @@ pub fn cycle_popup_overlay(
         .collect();
 
     let panel = container(column(rows))
-        .style(|_: &Theme| container::Style {
-            background: Some(Background::Color(PANEL_BG)),
-            border: Border {
-                color: PANEL_BORDER,
-                width: 1.0,
-                radius: 3.0.into(),
-            },
-            ..Default::default()
-        })
+        .style(container::bordered_box)
         .width(Length::Fixed(150.0));
 
     let positioned = crate::ui::pin_at(anchor, opaque(panel));
@@ -36,16 +28,10 @@ pub fn cycle_popup_overlay(
 }
 
 fn item_row(handle: acadrust::Handle, label: String) -> Element<'static, Message> {
-    let content = text(label).size(11).color(LABEL).align_y(iced::Center);
+    let content = text(label).size(11).align_y(iced::Center);
     let btn = button(content)
         .on_press(Message::CycleSelect(handle))
-        .style(|_: &Theme, status| button::Style {
-            background: Some(Background::Color(match status {
-                button::Status::Hovered => ROW_HOVER,
-                _ => Color::TRANSPARENT,
-            })),
-            ..Default::default()
-        })
+        .style(button::subtle)
         .width(Fill)
         .padding([4, 10]);
     // Highlight the underlying object while the cursor is over this row.
@@ -54,30 +40,3 @@ fn item_row(handle: acadrust::Handle, label: String) -> Element<'static, Message
         .on_exit(Message::CycleHoverExit(handle))
         .into()
 }
-
-// ── Colours ───────────────────────────────────────────────────────────────
-
-const PANEL_BG: Color = Color {
-    r: 0.15,
-    g: 0.15,
-    b: 0.15,
-    a: 1.0,
-};
-const PANEL_BORDER: Color = Color {
-    r: 0.32,
-    g: 0.32,
-    b: 0.32,
-    a: 1.0,
-};
-const ROW_HOVER: Color = Color {
-    r: 0.22,
-    g: 0.45,
-    b: 0.62,
-    a: 1.0,
-};
-const LABEL: Color = Color {
-    r: 0.92,
-    g: 0.92,
-    b: 0.92,
-    a: 1.0,
-};