Fix typo in Keyframes section (#29084)

advanced_html_css/animation/keyframes.md

@@ -115,7 +115,7 @@ Now it's time to introduce the shorthand notation for our animation properties a
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-Here we added another keyframe for when the `animation-duration` is at 50%, or 1 second. This means as well as the `background-color` changing to an additional value, we have also specified that the ball double in size. Just be aware that additional keyframes are always defined in percentages. Only the `0%/100%` values may use the `from/to` alias.
+Here we added another keyframe for when the `animation-duration` is at 50%, or 1 second. This means as well as the `background-color` changing to an additional value, we have also specified that the ball doubles in size. Just be aware that additional keyframes are always defined in percentages. Only the `0%/100%` values may use the `from/to` alias.
 
 Hopefully, this gives you a glimpse into the power the `@keyframes` syntax provides to you when it comes to controlling the animation of an element's properties. You can add keyframes whenever you want, control whatever CSS-animatable properties you want, and have the control to add some real creative flair to your website elements.