Theme development

I want to show a custom content if current URL contain certain words. So far, I'm able to achieve this with the code below (works perfectly), if the path contain the word 'cart'. I want to be able to check for other words like 'blog', 'event' and 'news'. How do I go about this.

On my page I have several blocks, some have a class task-success and others have the class task-alert.

How to add a class task-alert to the menu if the class task-danger is present in the page ?

I managed to do this with the JS code below. But the class is added to the menu link only if I am on the page (the page containing the task-danger class). If I change pages, the class is not added to the menu link.

I have a site with Drupal 8. I am an anonymous user. I am visiting the page "Messaging" which is accessible only to the authenticated user. The page displays a code 403 with a block to connect me.

When I connect, I arrive on the homepage of the site.

I created a 403 custom page with a "Connect" button in a Twig file of my theme:

<a class="use-ajax btn btn-success btn-md" href="/user/login" data-dialog-type="modal">Se connecter</a>

How to make the user who logs on a 403 page, return to the current page?

I'm using Drupal 8.6.9 with a Bootstrap sub theme and I've enabled a forum on my site. Unfortunately the forum page does not have any CSS

styling. Could someone provide me some guidance as to how I can improve the look of the forum page...?

Submenu is not expanding on mouse click --- I followed all the normal steps to fix like going to main navigation block configuration Visibility level 2

Here is my Header Section

I was using last years Bootstrap (after changing from Adaptivetheme) - from Bootstrap CDN - and Overwriting almost all styles I needed in my own styles.css ..... and often angry - that some Bootstrap CDN elements are trying to come into my CSS way... and also - that Bootstrap CDN seems loading a LOT of unnecessary staff for me, that I have to overwrite, and then - why is it even loading that unnecessary staff?!

So.... yesterday I downloaded Bootstrap library and put it locally.... my site is anyway on cloudflare.... so I hope the performance impact should be minimal....