diff --git a/frontend/src/app/site-finder/analysis/[cad]/ptica/ptica.module.css b/frontend/src/app/site-finder/analysis/[cad]/ptica/ptica.module.css
index 7f58998c..c1f4bd48 100644
--- a/frontend/src/app/site-finder/analysis/[cad]/ptica/ptica.module.css
+++ b/frontend/src/app/site-finder/analysis/[cad]/ptica/ptica.module.css
@@ -92,7 +92,12 @@
     100% 100%;
 }
 
-.pticaRoot button {
+/* `:where(button)` keeps specificity at (0,1,0) so per-component button classes
+   (.navItem 9px, .tab 11px, .detailBtn 9px, .ptab …) win their font-size. With a
+   bare `.pticaRoot button` (0,1,1) the `font: inherit` reset beat those classes
+   and forced every cockpit button back to the root 13px — overflowing the 96px
+   rail and oversizing tabs/buttons. Matches the prototype's bare `button {}`. */
+.pticaRoot :where(button) {
   font: inherit;
   cursor: pointer;
   color: inherit;