, W3Schools is optimized for learning and training. See the Pen CSS Fade-in Transition on Hover by HubSpot (@hubspot) on CodePen. You can list the keyframe percentages in any order; they will be handled in the order they should occur. (from -300px to 0): The w3-animate-bottom class slides in an element from the The properties ensure your fade-out animation code works across different browsers. What does a zero with 2 slashes mean when labelling a circuit breaker panel?