Harden CMS security and theme contrast

src/components/public/radio-player.tsx

@@ -249,7 +249,7 @@ export default function RadioPlayer() {
             border: "none",
             cursor: "pointer",
             background: primary,
-            color: "var(--button-text-color)",
+            color: "var(--button-text-color-readable, var(--button-text-color))",
             fontSize: "1rem",
             lineHeight: 1,
           }}