gnome-shell.css

#panel {
  background-gradient-direction: none;
  background-color: #1d2128;
  border-radius: 7px;
  margin-top: 3px;
  margin-bottom: 3px;
  margin-left: 10px;
  margin-right: 10px;
  height: 35px;
	
}

#panel #panelActivities.panel-button {
  -natural-hpadding: 12px; 
}

#panel .panel-button#panelActivities {
  background-image: url("assets/activities.png");
  background-position: center top;
  background-size: auto; 
  color: transparent;
  background-color: transparent;
  box-shadow: none;
}

#panel .panel-button#panelActivities > * {
  width: 24px;
}


Gjs_ui_panel_AggregateMenu.panel-button{
}


VitalsMenuButton.panel-button{
}

gtk-dark.css

* {
  padding: 100px;
}