update tailwind v4, remove sass and postcss dependency

assets/css/safe.css

@@ -0,0 +1,8 @@
+/* swiper pagination */
+.swiper-pagination-bullet {
+  @apply !h-2.5 !w-2.5 !bg-theme-light !opacity-100 dark:!bg-darkmode-theme-light;
+}
+
+.swiper-pagination-bullet-active {
+  @apply !h-4 !w-4 !bg-primary dark:!bg-darkmode-primary;
+}