add checkbox

crates/theme/src/lib.rs

@@ -55,6 +55,8 @@ impl Global for Theme {}
 /// Corner radii components paint from; grows one class at a time.
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub struct Radius {
+    /// Small controls: checkbox and radio indicators.
+    pub sm: Pixels,
     pub control: Pixels,
     /// Pill and circle shapes.
     pub full: Pixels,
@@ -63,6 +65,7 @@ pub struct Radius {
 impl Default for Radius {
     fn default() -> Self {
         Self {
+            sm: px(4.),
             control: px(6.),
             full: px(9999.),
         }