how to apply styles conditionally inside multiple id selection in sass? 

for eg. if there is following html file

// demo.html

```
 <div id="id1">
   <h1></h1>
 </div>
 <div id="id2">
   <h1></h1>
 </div>
 <div id="id3">
   <h1></h1>
 </div>

```

then I should be able to apply styles like following.

// styles.scss

```
#id1,
#id2,
#id3 {
  if(id1): apply red color to <h1>
  else: apply blue color to <h1> // ie to <h1>s inside id2 and id3 divs.

}

```