.simple-tooltip:hover .tooltip { opacity: 0.9; } .tooltip { opacity: 0; transition: opacity 200ms ease-in; font-size: 12px; line-height: 1; background-color: #616161; color: white; padding: 8px; border-radius: 2px; position: absolute; right: calc(100% + 8px); pointer-events: none; white-space: nowrap; }