Hello Juergen,
1/ The next custom CSS code can be used:
.order-tracking input::placeholder { color: #222; opacity: 1; }
2/ It helped to solve the conflict on the mobile view.
Additionally, we suggest that please try to enable the following options in the WP Rocket plugin: Settings -> File Optimization -> Minify CSS files and Settings -> File Optimization -> Minify JavaScript files (details in the screenshot https://prnt.sc/rKPs6o5eVBth). Please read our theme documentation as well on speeding up your website: https://xstore.helpscoutdocs.com/article/100-how-to-speed-up-my-website & https://xstore.helpscoutdocs.com/article/128-how-to-improve-wp-rocket-settings-with-xstore
Best Regards, 8Theme’s Team
