I am using bootstrap with my wordpress site , its perfect when we uploaded to live server but when we hover over/ click nav item in mobile this is what happens 
right now if i click on any of the nav items its not clicked and bottom one comes just right to upper one , now i don’t remember if i modified some css for navigation code while doing this site but what i expect a single css rule will make it fine can someone help me to fix this ?
In hover and click some css get overrides which is applied for desktop version.
You have to override desktop version css with media query for mobiles.