Each sidebar is wrapped with a class that contains the category name, so for the UX category that would be .ux-sidebar. You can use these classes to style individual sidebars.
The html tag on pages with sidebars also has a class added so you can use html.custom-sidebar to apply styles on all pages that have a sidebar.
this would make an incredibly powerful navigation tool if it showed the most common in each category and tag-page and it was positioned in a banner, or other item at the top of the page.
In case you weren’t aware, there is already an optional tag drop-down in vanilla Discourse (shown in the image above) which appears above the topic list.
Can you describe this problem a little more? The sidebar only appears for one category and no others?
Do all the categories you’re trying have topics with more than 3 tags? the sidebar won’t show if there are less than 3 tags within a specific category.
Yes, I think I can add some support for other pages
There is no problem when i click directly (same page), but when i right click, open in new tab, there is message “Oops! That page doesn’t exist or is private.”
I’ve added a feature to optionally show the tag sidebar on the top menu pages (latest, top, new, etc). It’s disabled by default, you can enable it in the theme component’s settings.
That was my mistake, I didn’t consider subcategories and restructure the URL to fit. It’s fixed now.
That URL shows all the tags across all categories, when you’re within a category and click a tag in the sidebar I wanted to make it so you’re viewing that tag within the context of the current category.
I’m not entirely sure what you mean, can you give me a specific example?
These are all general CSS changes… if you want to make more style changes like these I suggest following a few CSS tutorials, CSS first steps - Learn web development | MDN is a good free one!
would be really cool if the max # of tags was increased to 100 and displayed in a responsive-filled height of a bubble text cloud sorted alphabetically. in other words, the more popular a tag the larger its font size. the “top 100” tags.
also, would be good if it was positioned horizontally above category lists for mobile. i really want this for mobile.
This is unfortunate, because these should be complimentary: the tag list for “all tags” view (and possibly also “no tags”), and the sidebar for specific tags. In fact, maybe they could be combined into a single component?
You must enable the 
