I’ve a header overlap on with white menu text (dark hero). My sticky header background is white and my navigation link colour is black. So when I scroll down on desktop the navigation area change perfectly. On mobile, when I open the page it’s all good whit the header overlap (white text). Once I scroll down my sticky header background is white (good) but my mobile menu button doesn’t change to black (as it happen on desktop with the navigation links) and stays white so basically disappear. How can I change the colour of the menu button only when I scroll down? There is a CSS or setting I can use?