Theme compatibility is the hardest problem in WordPress plugin development. Every theme has its own opinions about how headers should work — how they’re positioned, what z-index they occupy, what font styles cascade down to links, what overflow behavior applies to navigation containers. A mega menu plugin has to work inside all of this without breaking.
Most plugins handle this badly. They spray !important declarations everywhere, override theme styles with brute force, and hope for the best. It works until it doesn’t — and when it breaks, it’s very hard to debug.
Ruby Mega Menu takes a different approach.
High-specificity scoping without !important
Every CSS rule in Ruby is scoped under the selector nav#ruby-mega-menu.ruby-wrapper. This is a high-specificity selector — ID plus element type plus class — that beats most theme rules without needing !important. It’s specific enough to win most specificity battles, but it’s targeted enough that it doesn’t bleed into other parts of your theme.
This matters because !important creates its own problems. Once you have !important in a plugin’s CSS, any overrides you want to make from your theme or custom CSS also need !important. It becomes an arms race. Scoped high-specificity selectors are cleaner.
A dedicated reset layer
Ruby also ships with a CSS reset scoped to its own wrapper. This reset neutralizes common theme rules that would otherwise interfere with the menu — things like box-sizing: content-box breaking grid calculations, or float: left cascading onto li elements and anchoring submenus in the wrong position, or global a { color } declarations overriding menu link colors.
The reset is surgical. It only touches elements inside the Ruby wrapper, so it has no effect on the rest of your theme.
Tested against real themes
Ruby has been tested against Avada, The7, and a range of other popular premium themes. These are themes with complex, opinionated header systems — exactly the kind that tend to break third-party plugins. The testing process surfaces real conflicts, which feed back into the reset layer and scoping strategy.
FSE and block theme support
For Full Site Editor themes, Ruby is added via a Custom HTML block rather than a Shortcode block. This avoids wpautop corruption — a common issue where WordPress wraps shortcode output in paragraph tags, breaking the menu structure. The plugin’s dynamic CSS loads once via the wp_head hook, preventing the double-load issue that can occur when shortcodes are processed multiple times.
Theme compatibility isn’t glamorous, but it’s where a lot of the real engineering in a menu plugin lives. Getting it right means users can install and configure without debugging, and that’s ultimately what makes a plugin worth recommending.