Generate unique class name in css file if it referenced in JSX

I want to request a feature. Rather than having to use styleName on every element we can put it only on parent element and use existing global class. So JSX syntax will more simpler to look.

For example when I use bootstrap:
```

```
Will much simpler to look if we put styleName only on parent element:
```

```

so SCSS:
```
.container { <-- generate only this to be a unique class Name
margin: 0;
.card {
font-size: 14px;
.card-header {
background: #ddd;
}
.card-body {
background: #f8f8f8;
}
}
}
```