Add style to coupon error inline message

[Manussakis]

This PR fixes the woocommerce/woocommerce#53534 issue caused by merging the woocommerce/woocommerce#48738 PR.

Screenshots

Cart page

Before

After

Checkout page

Before

After

How to test the changes in this Pull Request:

1. Go to both the Cart and Checkout pages.
2. Add an invalid coupon code.
3. Verify the error message shows up below the coupon input.
4. Verify the error message uses the $error color (red) and is left aligned.

Changelog

Fix – Edit, reply and author icons are now displayed in comment list form. #1319

[imanish003]

Hi @Manussakis, thank you for submitting this PR! I've reviewed the changes and have a clarifying question.

AFAIK This issue only occurs on classic Cart and Checkout pages. Is it correct?

Before your changes:

After reviewing your changes, I can confirm:

• The error message is now properly left-aligned
• The text color has been updated to use the standard error red
  

[Manussakis]

Hey @imanish003 👋

AFAIK This issue only occurs on classic Cart and Checkout pages. Is it correct?

Yes, that's correct!