Horizontal Sub-menu active states WordPress

Asad Iqbal answers:

May I take a look to your menu first?

Arnav Joy answers:

can you provide url or screenshot?

Hai Bui answers:

I can help you with this. Please provide the url.

Abdelhadi Touil answers:

Hi.
If you have some knowledge in html/css/jquery, you can have the same menu used in that website (http://socialchange.is/), because it's using Superfish menu, it's a jquery menu you can easily add to your website, here is the link to the menu page:
[[LINK href="http://users.tpg.com.au/j_birch/plugins/superfish/"]]http://users.tpg.com.au/j_birch/plugins/superfish/[[/LINK]]
to find the one you want, go to "Examples" tab:
[[LINK href="http://users.tpg.com.au/j_birch/plugins/superfish/#examples"]]http://users.tpg.com.au/j_birch/plugins/superfish/#examples[[/LINK]]
then go to "nav-bar style" tab, it's exactly the menu used in the link, and what you are looking for.
Good luck.

Jatin Soni answers:

Here is your solution.

If you haven't changed any specific current page class than use below class and it should work perfectly as it is tested.

ul.dt-nav > li.current-menu-item > a,ul.dt-nav > li.current_page_parent > a, ul.dt-nav > li > ul > li.current-menu-item > a{
color:#f80000;
}

Where ul.dt-nav will be your un order list ul class also if you are getting still problem give me access I will quickly finish this.

Wordpress by default apply current-menu-item on selected menu item list (li) and on parent item wordpress apply current_page_parent on (li) so both you can use for your job.

Adding wp_nav_menu check with yours and modify if needed.

<?php
wp_nav_menu( array(
'theme_location' => 'header_menu',
'menu_class' => 'dt-nav clearfix', // dt-nav is the class I used in css so you can change as yours, also clearfix to clearing li float
'container' => 'nav'
) );
?>