spinner { opacity: 0; transition: opacity 200ms ease-in-out; background-color: rgba(64, 64, 64, 0.5); } spinner.visible { opacity: 1; } .output-overlay { font-size: 96px; background-color: @theme_selected_bg_color; color: @theme_selected_fg_color; border-radius: 8px; opacity: 0.9; padding: 8px; } .output-overlay .description { font-size: 12px; }