fix close button placement on certain screen sizes

[hipstersmoothie]

PR Type

Bugfix

Describe the current behavior?

ON certain screen sizes the close button would overflow the modal

Describe the new behavior?

No overflow

PR Checklist

• Test: run npm run test and ensure that all tests pass
• Target master branch (or an appropriate release branch if appropriate for a bug fix)
• Ensure that your contribution follows standard accessibility guidelines. Use tools like https://webhint.io/ to validate your changes.

[ghost]

Thanks for opening a Pull Request! The reviewers will test the PR and highlight if there is any conflict or changes required. If the PR is approved we will proceed to merge the pull request 🙌