Fix input focus and placeholder color for footer section (#1005)

Co-authored-by: Emruz Hossain <hossainemruz@gmail.com>

assets/styles/sections/footer.scss

@@ -97,6 +97,10 @@ html[data-theme='dark'] {
       background-color: get-dark-color('bg-primary');
       &:focus {
         background-color: get-dark-color('bg-secondary');
+        color: get-dark-color('text-color');
+      }
+      &::placeholder {
+        color: get-dark-color('muted-text-color');
       }
     }