Understanding CSS Animation Conflicts: How to Fix Your fadein and slidedown Animations

Discover why your `fadein` animation works while `slidedown` doesn't. Learn how to properly use CSS animations together for a seamless effect in your web projects.
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This video is based on the question https://stackoverflow.com/q/72086017/ asked by the user 'Hoàng Minh Tuấn' ( https://stackoverflow.com/u/19014944/ ) and on the answer https://stackoverflow.com/a/72086084/ provided by the user 'Sigurd Mazanti' ( https://stackoverflow.com/u/14776809/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Understanding CSS Animation Conflicts: How to Fix Your fadein and slidedown Animations

When working with animations in CSS, you may encounter situations where certain animations on the same element don't behave as expected. A common question among developers, especially when using frameworks like React, is: Is there a conflict rule in CSS that causes some animations to fail? This guide addresses that concern and provides a comprehensive solution to using multiple animations effectively.

The Problem: Animation Conflict

In a recent situation, a developer found that their fadein keyframes worked perfectly fine, but their slidedown animations were not functioning as intended. Here’s a brief overview of their setup:

Keyframes Definition

The developer set up two animations in their CSS file:

[[See Video to Reveal this Text or Code Snippet]]

CSS Class Definition

The animation was being applied within a class for the text, but it only worked for one animation:

[[See Video to Reveal this Text or Code Snippet]]

React Component

The React component where this class was applied looks like this:

[[See Video to Reveal this Text or Code Snippet]]

Here, only the fadein animation seemed to be working. This raises the question of whether there are potential CSS conflicts at play.

The Solution: Correcting the Animation Syntax

The reason why only one of the animations worked is that CSS allows you to apply only one animation property per element if you don't separate them correctly. CSS reads the styles from top to bottom, and the last applied animation will take precedence. Thus, if two animations are specified without the correct syntax, only one will show.

How to Use Multiple Animations Together

To fix this, you need to separate multiple animation declarations with commas in the CSS properties. Here’s how you can structure the welcome__text class to ensure both animations play correctly:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of Animation Properties

animation: Lists all animations you want to apply to the element separated by commas. In this case, we have slidedown followed by fadein.

animation-fill-mode: This property determines how the CSS styles are applied before and after the animation plays. In this example, forwards allows the element to retain the final keyframe style.

animation-timing-function: Controls the speed of the animation over its duration, allowing you to set different functions for each animation, enhancing the visual effect.

Conclusion

By understanding how multiple animations can coexist on the same element, you can create engaging and effective animations for your web projects. In summary, remember to separate your animations with commas and ensure your CSS properties are appropriately defined. This approach allows you to leverage the full power of CSS animations without conflict, enabling you to create sophisticated visual experiences for users on your website.

Happy coding, and enjoy animating your applications!