A simple mega nav menu in pure CSS.

Mega navs are an effective feature for large menu content and surprisingly easy to implement. If you've wanted to put one together but didn't know where to start, this quick walkthrough is for you.

This implementation uses just CSS and nothing else. After creating a menu list, add <div class="mega-menu"> to the menu item where the mega nav should display. The following mega-menu class will hide the menu:

.mega-menu {
  background: #fff;
  border: 1px solid #ddd;
  border-radius: 0 0 3px 3px;
  opacity: 0;
  position: absolute;
  transition: all .3s ease .15s;
  visibility: hidden;
  width: 100%;
}

The mega nav is hidden until you hover over the menu item:

li:hover > .mega-menu {
  opacity: 1;
  overflow: visible;
  visibility: visible;
}

And voila...

This implementation uses ARIA landmark roles following WCAG 2.0 compliance for accessibility. Keyboard-only navigation isn't include.

Current versions of Chrome, Firefox, Safari, Opera, Edge, and IE8+.

The MIT License (MIT)