9.14 WCAG 2.1 Success Criterion 2.4.7 - Focus Visible
When a "text field" is selected, ensure it is clear that the focus has been moved into the "text field". For example, ensure the cursor is easily visible within the field so that users know where to begin typing.
Before Rectification
In the image above, there is no way to determine which field has the focus.
After Rectification
This image ensures that the vertical bar is visible. This shows that the focus is currently on the second field, and this helps those users with low vision or visual impairments determine where they are on a webpage.
WCAG 2.1 Reference:
https://www.w3.org/WAI/WCAG21/Understanding/focus-visible