Mobile navigation icons almost invisible

Does anyone know how to control the mobile navigation icons on the bottom of the screen on a Sumsung Android phone using the Chrome browser? When I view my website on my phone, the navigation icons on the bottom of the screen are almost invisible. I’ve tried everything that has been suggested to me to change them, but nothing works. The icons look fine when I use the Samsung browser.

Does this have anything to do with Grav? At no time do you refer to a website made with Grav or the theme used. It is impossible to help if the question is not specified correctly

The website was developed using Grav. The theme I used is learn4.