[Spectra One WordPress Theme]Menu Styles Disappear

A Spectra One WordPress Theme user met a problem:

The menu styles disappear. It was all working fine, but now the theme menu styles are missing.
I've already tried checking any problem with plugins interfering, I've also cleared all cache.

The page I need help with: https://gestiadvanx.com/

@gwkaplan

What’s The Problem?

I went to the user's site and find that when the page loads, the menu isn't showing correctly

problem showing menu

As illustrated, the menu is different from that of the official Spectra One demo.

Since I don't have access to the plugins and so on of the site, the only way I can help is to add the missing CSS back to the site here are the CSS codes:

CSS Codes to Solve the Issue

.wp-block-navigation__container{flex-grow: 1;
list-style: none;
--navigation-layout-justification-setting: center;
--navigation-layout-justify: center;
display: flex;
align-items: var(--navigation-layout-align,initial);
flex-wrap: var(--navigation-layout-wrap,wrap);
gap: var(--wp--preset--spacing--medium);}
.wp-block-navigation-item{align-items: center;
background-color: inherit;
display: flex;
position: relative;
letter-spacing: 0.25px;
gap: var(--wp--preset--spacing--medium);} 
.wp-block-navigation__container{flex-grow: 1;
list-style: none;
--navigation-layout-justification-setting: center;
--navigation-layout-justify: center;
display: flex;
align-items: var(--navigation-layout-align,initial);
flex-wrap: var(--navigation-layout-wrap,wrap);
gap: var(--wp--preset--spacing--medium);}
.wp-block-navigation-item{align-items: center;
background-color: inherit;
display: flex;
position: relative;
letter-spacing: 0.25px;
gap: var(--wp--preset--spacing--medium);} 
.wp-container-3.wp-container-3{flex-wrap: nowrap;
gap: var(--wp--preset--spacing--large);
justify-content: flex-end;}

And here is a detailed explanation of how to add custom CSS to WordPress.

Now, the menu will look like this:

correct menu

Please note that modifying the code requires caution. Always make a backup of your theme and site before making changes. The best way to check them is by testing them on the staging site(s) and if you have a third-party plugin, consider plugin conflicts as well.

Feel free to leave me a comment. (I'd be happy to provide some codes and show you where to add it. Please give me a link to your site so I can take a look directly, and point me to exactly where on your site you're looking to make the changes, as there are multiple places where blog posts and widgets might be displayed, and it'll be much better if we can look at it directly.)