Enhance high-contrast theme styles and improve product display

- Added placeholder color and opacity adjustments for high-contrast mode.
- Updated styles for search filters and categories in the left column to improve visibility.
- Enhanced featured products link styles for better contrast.
- Improved product price and shipping display, including discount and new flags.
- Standardized background and text colors for product descriptions and buttons.

.vscode/ftp-kr.sync.cache.json

@@ -52,9 +52,9 @@
     "custom": {},
     "custom-cron.php": {
       "type": "-",
-      "size": 1112,
+      "size": 1396,
       "lmtime": 0,
-      "modified": false
+      "modified": true
     },
     "customers.csv": {
       "type": "-",
@@ -98,7 +98,7 @@
     },
     "google-merchant_id-1.xml": {
       "type": "-",
-      "size": 18470225,
+      "size": 18798984,
       "lmtime": 0,
       "modified": true
     },