Define missing CSS variables to fix IDE warnings

Adds --color-text and --max-width-content to :root declaration to eliminate undefined variable warnings while maintaining the same visual appearance with proper fallback values.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Signed-off-by: James R. Perkins <jperkins@ibm.com>

Author: jamezp

public/css/bootstrap-theme.css

@@ -18,6 +18,10 @@
   --resteasy-bg-accent: #e8f2f7;      /* Light blue-gray */
   --resteasy-border: #d1dce3;         /* Cool border */
   --resteasy-text-muted: #5a6c7d;     /* Muted slate text */
+
+  /* Layout & Typography */
+  --color-text: #212529;              /* Default text color */
+  --max-width-content: 1200px;        /* Maximum content width */
 }
 
 /* ============================================