fixed tooltip illegibility due to similar color to bg on .sig-overlay when data-polarity='gravity'

src/static_src/scss/_card-deck.scss

@@ -603,6 +603,9 @@ html:has(.sig-backdrop) {
         color: rgba(var(--priUser), 1);
         border-color: rgba(var(--priUser), 0.15);
     }
+    // Caution tooltip: --tooltip-bg is black so priUser text (dark) would be invisible —
+    // override to secUser (light) so body text reads against the dark backdrop.
+    .sig-caution-tooltip { color: rgba(var(--secUser), 1); }
     // Polarity qualifier: terUser for gravity (quiUser is levity's equivalent)
     .sig-qualifier-above,
     .sig-qualifier-below { color: rgba(var(--terUser), 1); }