diff --git a/src/alsa-scarlett-gui.css b/src/alsa-scarlett-gui.css
index ca34abd..35b1177 100644
--- a/src/alsa-scarlett-gui.css
+++ b/src/alsa-scarlett-gui.css
@@ -38,8 +38,79 @@ button {
 
 button:checked {
   color: #ffffff;
+  border: 1px solid #202020;
 }
 
 button:hover {
   background: #202020;
 }
+
+button:disabled {
+  background: #000000;
+  color: #505050;
+}
+
+/* Button controls that are always disabled because they indicate status */
+button.fixed {
+  color: #ffffff;
+}
+
+/* Combobox controls that are always disabled because they indicate status */
+combobox.fixed > box > button {
+  color: #ffffff;
+}
+
+/* Buttons that glow when on */
+button.sync-status {
+  text-shadow: 0 0 5px #a00000, 0 0 15px #800000;
+}
+
+button.sync-status:checked {
+  text-shadow: 0 0 5px #00c000, 0 0 15px #00c000;
+}
+
+button.input-select:checked {
+  color: #ffffff;
+  text-shadow: 0 0 5px #00ff00, 0 0 10px #00ff00, 0 0 15px #00ff00;
+}
+
+button.input-link:checked {
+  text-shadow: 0 0 5px #00c000, 0 0 15px #00c000;
+}
+
+button.autogain:checked {
+  text-shadow: 0 0 5px #0000ff, 0 0 15px #0000ff;
+}
+
+button.safe:checked {
+  text-shadow: 0 0 5px #00c000, 0 0 15px #00c000;
+}
+
+button.inst:checked {
+  text-shadow: 0 0 5px #ff0000, 0 0 15px #ff0000;
+}
+
+.gen4 button.inst:checked {
+  text-shadow: 0 0 5px #00c000, 0 0 15px #00c000;
+}
+
+button.air:checked {
+  text-shadow: 0 0 5px #ffc000, 0 0 15px #ffc000;
+}
+
+button.pad:checked {
+  text-shadow: 0 0 5px #00c000, 0 0 15px #00c000;
+}
+
+button.phantom:checked {
+  text-shadow: 0 0 5px #ff0000, 0 0 15px #c00000;
+}
+
+.gen4 button.phantom:checked {
+  text-shadow: 0 0 5px #00c000, 0 0 15px #00c000;
+}
+
+/* Direct Monitor Checked (Solo) */
+.direct-monitor:checked {
+  text-shadow: 0 0 5px #00c000, 0 0 15px #00c000;
+}
diff --git a/src/iface-mixer.c b/src/iface-mixer.c
index d69213e..0dd4770 100644
--- a/src/iface-mixer.c
+++ b/src/iface-mixer.c
@@ -39,6 +39,8 @@ static void add_clock_source_control(
 
   GtkWidget *l = gtk_label_new("Clock Source");
   GtkWidget *w = make_combo_box_alsa_elem(clock_source);
+  gtk_widget_add_css_class(w, "clock-source");
+  gtk_widget_add_css_class(w, "fixed");
 
   gtk_box_append(GTK_BOX(b), l);
   gtk_box_append(GTK_BOX(b), w);
@@ -77,6 +79,8 @@ static void add_sync_status_control(
   GtkWidget *l = gtk_label_new("Sync Status");
   gtk_box_append(GTK_BOX(b), l);
   GtkWidget *w = make_boolean_alsa_elem(sync_status, "Unlocked", "Locked");
+  gtk_widget_add_css_class(w, "sync-status");
+  gtk_widget_add_css_class(w, "fixed");
   gtk_box_append(GTK_BOX(b), w);
 }
 
@@ -159,6 +163,7 @@ static void create_input_link_control(
   int               column_num
 ) {
   GtkWidget *w = make_boolean_alsa_elem(elem, "Link", NULL);
+  gtk_widget_add_css_class(w, "input-link");
 
   int from, to;
   get_two_num_from_string(elem->name, &from, &to);
@@ -186,6 +191,7 @@ static void create_input_autogain_control(
   int               column_num
 ) {
   GtkWidget *w = make_boolean_alsa_elem(elem, "Autogain", NULL);
+  gtk_widget_add_css_class(w, "autogain");
   gtk_widget_set_tooltip_text(
     w,
     "Autogain will listen to the input signal for 10 seconds and "
@@ -214,6 +220,7 @@ static void create_input_safe_control(
   int               column_num
 ) {
   GtkWidget *w = make_boolean_alsa_elem(elem, "Safe", NULL);
+  gtk_widget_add_css_class(w, "safe");
   gtk_widget_set_tooltip_text(
     w,
     "Enabling Safe Mode prevents the input from clipping by "
@@ -230,6 +237,7 @@ static void create_input_level_control(
   int               column_num
 ) {
   GtkWidget *w = make_boolean_alsa_elem(elem, "Inst", NULL);
+  gtk_widget_add_css_class(w, "inst");
   gtk_widget_set_tooltip_text(w, level_descr);
 
   gtk_grid_attach(GTK_GRID(grid), w, column_num, current_row, 1, 1);
@@ -242,6 +250,7 @@ static void create_input_air_switch_control(
   int               column_num
 ) {
   GtkWidget *w = make_boolean_alsa_elem(elem, "Air", NULL);
+  gtk_widget_add_css_class(w, "air");
   gtk_widget_set_tooltip_text(w, air_descr);
 
   gtk_grid_attach(GTK_GRID(grid), w, column_num, current_row, 1, 1);
@@ -254,6 +263,7 @@ static void create_input_air_enum_control(
   int               column_num
 ) {
   GtkWidget *w = make_combo_box_alsa_elem(elem);
+  gtk_widget_add_css_class(w, "air");
   gtk_widget_set_tooltip_text(w, air_descr);
 
   gtk_grid_attach(GTK_GRID(grid), w, column_num, current_row, 1, 1);
@@ -266,6 +276,7 @@ static void create_input_pad_control(
   int               column_num
 ) {
   GtkWidget *w = make_boolean_alsa_elem(elem, "Pad", NULL);
+  gtk_widget_add_css_class(w, "pad");
   gtk_widget_set_tooltip_text(
     w,
     "Enabling Pad engages a 10dB attenuator in the channel, giving "
@@ -282,6 +293,7 @@ static void create_input_phantom_control(
   int               column_num
 ) {
   GtkWidget *w = make_boolean_alsa_elem(elem, "48V", NULL);
+  gtk_widget_add_css_class(w, "phantom");
   gtk_widget_set_tooltip_text(w, phantom_descr);
 
   int from, to;
@@ -578,6 +590,16 @@ static GtkWidget *create_main_window_controls(struct alsa_card *card) {
   GtkWidget *top = gtk_grid_new();
   gtk_widget_add_css_class(top, "window-content");
   gtk_widget_add_css_class(top, "iface-mixer");
+
+  if (strstr(card->name, "4th Gen") ||
+      strstr(card->name, "Gen 4")) {
+    gtk_widget_add_css_class(top, "gen4");
+  } else if (strstr(card->name, "Scarlett")) {
+    gtk_widget_add_css_class(top, "scarlett");
+  } else if (strstr(card->name, "Clarett")) {
+    gtk_widget_add_css_class(top, "clarett");
+  }
+
   gtk_grid_set_spacing(GTK_GRID(top), 10);
 
   int input_count = get_max_elem_by_name(
diff --git a/src/iface-no-mixer.c b/src/iface-no-mixer.c
index 0c7aba1..76738f3 100644
--- a/src/iface-no-mixer.c
+++ b/src/iface-no-mixer.c
@@ -69,20 +69,24 @@ GtkWidget *create_iface_no_mixer_main(struct alsa_card *card) {
 
     if (strstr(elem->name, "Level Capture Enum")) {
       w = make_boolean_alsa_elem(elem, "Inst", NULL);
+      gtk_widget_add_css_class(w, "inst");
       gtk_widget_set_tooltip_text(w, level_descr);
       gtk_grid_attach(GTK_GRID(input_grid), w, line_num - 1, 1, 1, 1);
     } else if (strstr(elem->name, "Air Capture Switch")) {
       w = make_boolean_alsa_elem(elem, "Air", NULL);
+      gtk_widget_add_css_class(w, "air");
       gtk_widget_set_tooltip_text(w, air_descr);
       gtk_grid_attach(
         GTK_GRID(input_grid), w, line_num - 1, 1 + !is_solo, 1, 1
       );
     } else if (strstr(elem->name, "Phantom Power Capture Switch")) {
       w = make_boolean_alsa_elem(elem, "48V", NULL);
+      gtk_widget_add_css_class(w, "phantom");
       gtk_widget_set_tooltip_text(w, phantom_descr);
       gtk_grid_attach(GTK_GRID(input_grid), w, 0, 3, 1 + !is_solo, 1);
     } else if (strcmp(elem->name, "Direct Monitor Playback Switch") == 0) {
       w = make_boolean_alsa_elem(elem, "Direct Monitor", NULL);
+      gtk_widget_add_css_class(w, "direct-monitor");
       gtk_widget_set_tooltip_text(
         w,
         "Direct Monitor sends the analogue input signals to the "
@@ -93,6 +97,7 @@ GtkWidget *create_iface_no_mixer_main(struct alsa_card *card) {
       GtkWidget *l = gtk_label_new("Direct Monitor");
       gtk_grid_attach(GTK_GRID(output_grid), l, 0, 0, 1, 1);
       w = make_combo_box_alsa_elem(elem);
+      gtk_widget_add_css_class(w, "direct-monitor");
       gtk_widget_set_tooltip_text(
         w,
         "Direct Monitor sends the analogue input signals to the "
diff --git a/src/widget-input-select.c b/src/widget-input-select.c
index 5818967..45aba25 100644
--- a/src/widget-input-select.c
+++ b/src/widget-input-select.c
@@ -62,6 +62,8 @@ GtkWidget *make_input_select_alsa_elem(
   data->button = gtk_toggle_button_new();
   data->line_num = line_num;
 
+  gtk_widget_add_css_class(data->button, "input-select");
+
   char s[20];
   snprintf(s, 20, "%d", line_num);
   gtk_button_set_label(GTK_BUTTON(data->button), s);