diff --git a/app/assets/stylesheets/layout.scss b/app/assets/stylesheets/layout.scss
index 44ce26e..33bdf3f 100644
--- a/app/assets/stylesheets/layout.scss
+++ b/app/assets/stylesheets/layout.scss
@@ -61,4 +61,8 @@
 
 .form-label {
   font-size: 1.3rem;
+}
+
+.highlight-when-nonempty:not([value=""]) {
+  @extend .border-primary
 }
\ No newline at end of file
diff --git a/app/views/checks/index.html.slim b/app/views/checks/index.html.slim
index 126e60e..37493c1 100644
--- a/app/views/checks/index.html.slim
+++ b/app/views/checks/index.html.slim
@@ -10,17 +10,17 @@ h1
       .me-3
         = f.check_box :principle_id_in, checked: @q[:principle_id_in].include?(principle.id), label: principle.name_de, id: "principle_id_in_#{principle.id}"
   = f.submit
-
-.card.mb-3
-  .card-header.d-flex data-bs-toggle="collapse" href="#filter-form" role="button" aria-expanded="#{filter_params.present?}" aria-controler="filter-form" class="#{"text-bg-primary" if filter_params.present?}"
+- filter_active = filter_params.to_h.any? { |_, v| v.present? }
+.card.mb-3 class="#{"border-primary" if filter_active }"
+  .card-header.d-flex data-bs-toggle="collapse" href="#filter-form" role="button" aria-expanded="#{filter_active}" aria-controler="filter-form" class="#{"text-bg-primary" if filter_active}"
     span.bi.bi-funnel
     strong.ms-2 Filter
-  .card-body.collapse id="filter-form" class="#{"show" if filter_params.present?}"
+  .card-body.collapse id="filter-form" class="#{"show" if filter_active}"
     = bootstrap_form_with(url: checks_path, method: :get, scope: :filter) do |form|
       = form.hidden_field :page, value: params[:page] if params[:page]
       .row
         .col-lg-12
-          = form.text_field(:s, placeholder: "suchen...", hide_label: true, value: filter_params[:s])
+          = form.text_field(:s, placeholder: "suchen...", class: "highlight-when-nonempty", hide_label: true, value: filter_params[:s] || "")
         .col-lg-2 
           label.fw-bold = Principle.model_name.human(count: 2)
           - Principle.all.sort_by(&:name_de).each do |principle|
@@ -49,7 +49,7 @@ h1
       .row.mt-3
         .col
           = form.submit name: "", value: "Filtern"
-          = link_to "Filter löschen", checks_path, class: "btn btn-outline-secondary ms-3", data: { turbo_prefetch: false } if filter_params.keys.any?
+          = link_to "Filter löschen", checks_path, class: "btn btn-primary ms-3", data: { turbo_prefetch: false } if filter_params.keys.any?
 
 table.table.table-striped
   thead