Reply To: Are there any responsive Bbpress-templates to buy?

You can follow the last entry i added to the very bottom.

it should help with most of the topic icons.

https://codex.bbpress.org/layout-and-functionality-examples-you-can-use/#24-show-status-labels-for-bbpress-topics

i will put how to use CSS at the bottom later.

but the category/forum icons you might need a custom way to list the forums , im going to need more time on that.

your CSS is wrong too .

you can use these as examples

.bbpress a.forum-title:before {
  font: normal 16px/1 'Fontawesome';
  content: '\f07c';
  margin-right: 5px;
  float: left;
  padding-top: 3px;
  color: #222;
}

.bbpress a.forum-link:before {
  font: normal 16px/1 'Fontawesome';
  content: '\f016';
  margin-right: 5px;
  float: left;
  padding-top: 3px;
  color: #222;
}