在导航栏中更改当前活动页面的颜色/背景

I'm designing my mobile website and using big tabs for navigation links, how can I show which page the user is currently on e.g the link background is red for example, without manually changing the css on each link per separate page.

My page uses a server side include using PHP for my header which includes my navigation. How can I add a class to separate pages this way?

You can do it using pure CSS.

Watch these reference videos.

Part - 1 Part - 2

Hope it helps.