app/views/proposals/_categories.html.erb
<div class="sidebar-divider"></div>
<h2 class="sidebar-title"><%= t("shared.tags_cloud.categories") %></h2>
<br>
<ul id="categories" class="no-bullet categories">
<% @categories.each do |category| %>
<li class="inline-block">
<% css_class = { class: "is-active" } if params[:search] == category.name %>
<%= link_to category.name, proposals_path(search: category.name), css_class || {} %>
</li>
<% end %>
</ul>