fix: 내 편지함 디자인 보이지 않는 문제 해결

- gradietn class에 !important를 적용

Author: nirii00

src/styles/utilities.css

@@ -90,22 +90,22 @@
 
   /* letter-box */
   .window-bg {
-    background: linear-gradient(to bottom, #d5b695, #b3895d);
+    background: linear-gradient(to bottom, #d5b695, #b3895d) !important;
   }
 
   .window-top-checked {
-    background: linear-gradient(to bottom, #ffffff, #fff5ed);
+    background: linear-gradient(to bottom, #ffffff, #fff5ed) !important;
   }
 
   .window-top-unChecked {
-    background: linear-gradient(to bottom, #ffffff, #fff4f2);
+    background: linear-gradient(to bottom, #ffffff, #fff4f2) !important;
   }
 
   .window-bottom-checked {
-    background: linear-gradient(to bottom, #FFF7E3, #FFE197);
+    background: linear-gradient(to bottom, #fff7e3, #ffe197) !important;
   }
 
   .window-bottom-unChecked {
-    background: linear-gradient(to bottom, #FFF4F2, #FFE6E3);
+    background: linear-gradient(to bottom, #fff4f2, #ffe6e3) !important;
   }
 }