How Inheritance Works in SASS

The gist of the @extend directive is that it adds an extending selector to any stylesheet where the extending selector appears (in our example, .warning):

Let's look at an example:

.warning {
	border: 1px solid;
	background-color: #ffd900;
}
.warning .instruction {
	background-image: url("/image/warning.png");
}
.personalWarning {
	@extend .warning;
	border-width: 3px;
}

Now let's look at the compilation result:

.warning, .personalWarning {
	border: 1px solid;
	background-color: #ffd900;
}

.warning .instruction, .personalWarning .instruction {
	background-image: url("/image/warning.png");
}
	  
.personalWarning {
	border-width: 3px;
}

Tell me what the result of compiling the following code will be:

#product-card p{
	color: #460707;
	padding: 10px;
}

#product-card-title {
	@extend #product-card;
	font-weight: 600px;
}

Tell me what the result of compiling the following code will be:

.link .main-block{
	font-size: 14px;
	text-decoration: dashed;
}

.active-link {
	@extend .link;
	color: red;
}

Tell me what the result of compiling the following code will be:

.link .main-block{
	font-weight: bold;
	text-decoration: none;
}

.active {
	color: red;
}

.active-link {
	@extend .link;
	@extend .active;
}