The file report_feedback/styles.css contains styling rules with very vague selectors, that are causing an impact on other areas of Moodle:

 a {

    color: #005E8D;

    text-decoration: none;

}

a, a:visited {

    color: #005E8D;

}

Moodle compiles and caches all CSS files together. This means the contents of your styles.css file are delivered to users whatever page they're accessing in Moodle - whether it's in your plugin or not. These vague rules are causing links in other places in Moodle to appear in this colour.

We were having problems where links in our Moodle with the CSS classes "btn btn-primary" were appearing with blue text on a blue background. We traced it to the a:visited rule in your styles.php file. Removing these rules solved our issue.

If you want to have custom link colours on your plugin's page, please use a more specific selector. Something like .path-report-myfeedback a:visited {} would be a big improvement.