SOLUTION:
when I cut and paste the .js & .css files related to my jquery code and place them at the beginning of the head before including any of my style codes
that means include the jquery library and css file right after the head tag <head>
hope its clear
I don't understand why it is so, but my problem solved
if somebody understands the concept behind it please share it here
----- It's Amazing Blessing!
when I share my problem here I get it solved even by my self but when I don't share it, I struggle.
Thanks 🙂