Something like this maybe?!

```less
.alert-announcement {
  &.container {
  	border-radius: 0;
  	margin-bottom: 0;
    padding: @alert-padding;
  }
  > .close {
    right: 0;
  }
}
```

`.alert` there is adding too much crap that is already applied since there is class name and I made it a bit more Lessy :)