can i use multiple themes?

[yohan0]

hi
is there any solution to use different themes each category?

if i modify code myself, please give me some hints for this
I am a beginner in nodejs

[Brophy]

You could do some CSS based overrides.

This is something I use in my custom css on the admin panel, it looks to see if you are either in a category or topic of a certain category, in this instance the "Red vs Blue Discussion" category (but using the slug)

body[class*=page-category-red-vs-blue-discussion], body[class*=page-topic-category-red-vs-blue-discussion] {
    background-image: url(/assets/uploads/system/rvb-bg.jpg) !important;
    .navbar-default {
        border-bottom: 3px #dd0000 solid;
        border-image: linear-gradient(to right, red, blue);
        border-image-slice: 1;
    }
    .btn-primary, .btn-info {
        color: #fff;
        background-color: #dd0000;
        border-color: #dd1111;
    }
    .btn-primary:hover {
        color: #fff;
        background-color: #bb0000;
        border-color: #bb1111;
    }
    .btn-info.active, .btn-info.focus, .btn-info:active, .btn-info:focus, .btn-info:hover, .open > .dropdown-toggle.btn-info {
        color: #fff;
        background-color: #bb0000;
        border-color: #bb1111;
    }
    .navbar-default .navbar-nav > .active > a, .navbar-default .navbar-nav > .active > a:focus, .navbar-default .navbar-nav > .active > a:hover {
        color: #000;
        background-color: #bb0000;
    }
    .composer .mobile-navbar {
        background-color: #dd0000;
    }
}

Examples of the overrides can be seen here:
Normal: https://saesrpg.uk/categories
Override: https://saesrpg.uk/category/25/red-vs-blue-discussion