diff --git a/firmware/components/display-classic.yaml b/firmware/components/display-classic.yaml
index 02c64ce..019be54 100644
--- a/firmware/components/display-classic.yaml
+++ b/firmware/components/display-classic.yaml
@@ -86,9 +86,13 @@ lvgl:
                   max_value: 1
                   value: 0
                   adjustable: false
-                  main:
-                    arc_color: 0x444444
-                    arc_width: 10
+                  # arc_color/arc_width are flattened to top-level (MAIN part) rather than nested
+                  # under a "main:" key — an explicit "main:" sub-block silently suppresses the
+                  # implicit top-level MAIN-part properties (align/width/height/x/y), verified via
+                  # isolated test compile. indicator:/knob: below are unaffected since those are
+                  # genuinely separate, non-MAIN parts that require nesting.
+                  arc_color: 0x444444
+                  arc_width: 10
                   indicator:
                     arc_opa: transp
                   knob:
@@ -105,8 +109,7 @@ lvgl:
                   max_value: 90
                   value: 70
                   adjustable: true
-                  main:
-                    arc_opa: transp
+                  arc_opa: transp   # flattened, see dial_bg_arc comment above
                   indicator:
                     arc_color: 0xFF3B30
                     arc_width: 10
@@ -138,8 +141,7 @@ lvgl:
                   max_value: 90
                   value: 75
                   adjustable: true
-                  main:
-                    arc_opa: transp
+                  arc_opa: transp   # flattened, see dial_bg_arc comment above
                   indicator:
                     arc_color: 0x0A84FF
                     arc_width: 10