* [**transition**](https://www.w3schools.com/cssref/css3_pr_transition.asp)
```
transition: property duration timing-function delay;
```
* [**animation**](https://www.w3schools.com/cssref/css3_pr_animation.asp)
```
animation: name duration timing-function delay iteration-count direction fill-mode play-state;
```
* [**@keyframes**](https://www.w3schools.com/cssref/css3_pr_animation-keyframes.asp)：定義了具體的動畫實現，一般配合animation 使用。
* [**animation vs transition**](https://cssanimation.rocks/transition-vs-animation/)
