i want to change my scrollbar design using css. i use this css but it only apply on chrome,

```
<style>

::-webkit-scrollbar {
    width: 12px;
}

::-webkit-scrollbar-track {
    -webkit-box-shadow: inset 0 0 6px rgba(0,0,0,0.3); 
    border-radius: 10px;
}

::-webkit-scrollbar-thumb {
    border-radius: 10px;
    -webkit-box-shadow: inset 0 0 6px rgba(0,0,0,0.5); 
}
</style>

```

tell me how can i change my scrollbar in firefox using css.

thanks in advance