Header hover animation not working on home page

Site URL: https://howtousepsychedelics.com

So, with some help from people here and the internet, I've managed to animate the header menu items when hovering on each item, including the drop down menu. The animation is a simple fade, but, it really adds to the experience.

Anyways, the fade hover animation works perfectly on every single page of the website, EXCEPT the home page. On the home page, there is no fade hover animation. 

Can someone help me solve this issue?

So far, the code I've used include:

CSS

//Header Font Size
.header-nav-item a {
    font-size:18px !important;
}

//Stylized Folder Dropdown Menu
.header-nav .header-nav-item--folder .header-nav-folder-content .header-nav-folder-item {
line-height: 1.6;
}

//Fix Header for Hover Effect
.tweak-transparent-header:not(.header--menu-open) .header-announcement-bar-wrapper.black .header-nav-wrapper a:hover {
opacity: .4
}

//DropDownMenu Fading
.header .header-nav .header-nav-item--folder .header-nav-folder-content {
  transition: ease-in-out 0.5s;
}

Thank you for your help and input!

Take care.

Edit your code to this

//Header Font Size
.header-nav-item a {
    font-size:18px !important;
}

//Stylized Folder Dropdown Menu
.header-nav .header-nav-item--folder .header-nav-folder-content .header-nav-folder-item {
line-height: 1.6;
}

//Fix Header for Hover Effect
body:not(.header--menu-open) .header-announcement-bar-wrapper.black .header-nav-wrapper a:hover {
opacity: .4 !important;
}

//DropDownMenu Fading
.header .header-nav .header-nav-item--folder .header-nav-folder-content {
  transition: ease-in-out 0.5s;
}

Thank you, but, it didn't work! There is still the missing fading on the words.

Thank you! Second one worked!