css border-radius missing

# css border-radius missing


https://github.com/Code-Pop/Intro-to-Vue-3/blob/vue2_version/assets/styles.css#L24

![image](https://user-images.githubusercontent.com/7291672/108596069-9faf2180-73bd-11eb-98e9-1e674f986733.png)


```diff

.color-box {
   width: 40px;
   height: 40px;
   margin-top: 5px;
+ border-radius: 50%;
}
```