refactor: replace theme color utility classes with direct hex values

remove unused theme color background utility classes from background.scss,
swap all instances of bg-theme-color-50 and bg-theme-color-500 with their
corresponding hex values across vue components, and update bg-liner gradient
to use direct hex colors instead of theme variables

src/pages-order/order/components/FooterSection/index.vue

@@ -6,7 +6,7 @@
       申请退款
     </button>
     <button :class="[
-      'right border-none rounded-10 flex flex-full flex-items-center flex-justify-center font-size-14 font-500 bg-theme-color-500',
+      'right border-none rounded-10 flex flex-full flex-items-center flex-justify-center font-size-14 font-500 bg-[#0CCD58]',
       {
         'bg-[#ff3d60]': statusCode === '0',
         'color-white': ['1', '2', '3', '4', '5', '6'].includes(statusCode),