[MAINTAIN-154] fixed styles for alert's slider in header and footer for mobile screen

[aleevas]

Original Issue, this PR is going to fix: MAINTAIN-154

This should fix issues for Rose and Lily themes:

• a white line under header and before alerts
• a different height of alert's slider in mobile view
• added hover style for alert button

Steps for review

• [ ] got to front page with Rose theme
• [ ] verify that you have hover effects for alert button
• [ ] switch mobile screen
• [ ] verify that you can't see the white line before alerts
• [ ] verify that you can;t see white line before alert slider
• [ ] verify the same for Lily theme

General checks

• [ ] All coding styles are fulfilled and there are no any issues reported by CodeSniffer. See Code of Conduct.
• [ ] Try to use Conventional commit messages accordingly to the standard https://www.conventionalcommits.org/en/v1.0.0/#specification
• [ ] Documentation has been updated according to PR changes.
• [ ] Steps for review have been provided according to PR changes.
  
• [ ] Make sure you've provided all necessary hook_update_N to support upgrade path.
• [ ] Make sure your git email is associated with account on drupal.org, otherwise you won't get commits there.
  
• [ ] If you would like to get credits on drupal.org, check documentation.

Thank you for your contribution!

[gundevel]

Can one of the admins verify this patch? Use "o+k to test" or ''t+est this please" for manual build execution.

[hamrant]

ok to test

[gundevel]

Build comment file:

Check Open Y Installation Wizard at http://install.openy.cibox.tools/build3314/install.php

---

Test PASSed. Refer to this link for build results (access rights to CI server needed): http://openy.cibox.tools:8080/job/PR_BUILDER_COMPOSER/3314/

[gundevel]

Open Y Upgrade Path site check installed at http://upgrade.openy.cibox.tools/build3314/

[gundevel]

Build comment file:

Check Open Y Installation Wizard at http://install.openy.cibox.tools/build3317/install.php

---

Test PASSed. Refer to this link for build results (access rights to CI server needed): http://openy.cibox.tools:8080/job/PR_BUILDER_COMPOSER/3317/

[gundevel]

Open Y Upgrade Path site check installed at http://upgrade.openy.cibox.tools/build3317/