Can I check parent element has specific class in sass?

Question

I want to assign value conditionally if parent element has a specific class. Exp:

HTML

<div class="parent">
    <div class="child">Some Text</div>
</div>

CSS

.child {
    font-size: 16px;
}

but if parent element has a class named "big"

HTML

<div class="parent big">
    <div class="child">Some Text</div>
</div>

I want to change value as follows

CSS

.child {
    font-size: 20px;
}

For example as follows:

.child {
  font-size: parent.hasClass('big') ? 20px : 16px;
}

How can I do that in SASS?

Answer 1

Simply create two rules:

.child {font-size: 16px;}
.big .child {font-size: 20px;}

---

In SASS it would be

.child
    font-size: 16px

    .big &
        font-size: 20px

Answer 2

It's impossible using pure CSS (the whole idea is cascading). But there might be a way using SASS. Check this out:

http://thesassway.com/intermediate/referencing-parent-selectors-using-ampersand

EDIT: Another option would be using JavaScript, like Jpegzilla suggested.