功能：完善自定义主题与独立登录会话

frontend-web/src/components/ui/button.tsx

@@ -10,7 +10,7 @@ const buttonVariants = cva(
     variants: {
       variant: {
         default:
-          "cursor-pointer bg-primary text-primary-foreground hover:bg-primary/90",
+            "cursor-pointer bg-primary text-[var(--button-foreground,var(--primary-foreground))] hover:bg-primary/90",
         destructive:
           "cursor-pointer bg-destructive text-white hover:bg-destructive/90 focus-visible:ring-destructive/20 dark:focus-visible:ring-destructive/40 dark:bg-destructive/60",
         outline: