fix(dark): hero text + button legibility on navy ground (Phase 18 W3)

Bind page-text/page-text-muted tokens directly in hero base rules (drop
:global overrides); dark-mode overrides for btn-primary (green-accent fill)
and btn-ghost (white text, light border).

DeepDrftPublic.Client/Controls/DeepDrftHero.razor.css

@@ -36,7 +36,7 @@
     font-weight: 300;
     line-height: 0.92;
     letter-spacing: -0.02em;
-    color: var(--deepdrft-navy);
+    color: var(--deepdrft-page-text);
     margin-bottom: 0.5rem;
     animation-delay: 0.22s;
 }
@@ -51,7 +51,7 @@
     font-size: clamp(1rem, 2vw, 1.35rem);
     font-weight: 300;
     font-style: italic;
-    color: var(--deepdrft-muted);
+    color: var(--deepdrft-page-text-muted);
     margin-bottom: 3rem;
     letter-spacing: 0.04em;
     animation-delay: 0.34s;
@@ -61,7 +61,7 @@
     font-family: var(--deepdrft-font-body);
     font-size: 0.92rem;
     line-height: 1.75;
-    color: var(--deepdrft-navy);
+    color: var(--deepdrft-page-text);
     opacity: 0.7;
     max-width: 36ch;
     margin-bottom: 3rem;
@@ -82,17 +82,10 @@
     }
 }
 
-/* Dark-mode text overrides (Phase 18, Correction B).
-   Light mode is pixel-identical — no changes to the rules above.
-   In dark, the navy page ground makes --deepdrft-navy text invisible; invert to light tokens. */
-:global(.deepdrft-theme-dark) .hero-title {
-    color: var(--deepdrft-page-text);
-}
-
+/* Dark-mode accent override (Phase 18, Wave 3).
+   .hero-title and .hero-desc bind --deepdrft-page-text directly above (theme-aware).
+   The em italic is the only element needing an explicit dark lift:
+   --deepdrft-green (#1A3C34) is low-contrast on the navy ground; lift to green-accent. */
 :global(.deepdrft-theme-dark) .hero-title em {
     color: var(--deepdrft-green-accent);
 }
-
-:global(.deepdrft-theme-dark) .hero-desc {
-    color: var(--deepdrft-page-text);
-}