Grouping and Nesting in CSS

There are two ways that you can simplify your code — both HTML and CSS — and make it easier to manage.

Grouping

You can give the same properties to a number of selectors without having to repeat them.

For example, if you have something like:

h2 {
    color: red;
}

.thisOtherClass {
    color: red;
}

.yetAnotherClass {
    color: red;
}

You can simply separate selectors with commas in one line and apply the same properties to them all so, making the above:

h2, .thisOtherClass, .yetAnotherClass {
    color: red;
}

Nesting

If the CSS is structured well, there shouldn’t be a need to use many class or ID selectors. This is because you can specify properties to selectors within other selectors.

For example:

#top {
    background-color: #ccc;
    padding: 1em
}

#top h1 {
    color: #ff0;
}

#top p {
    color: red;
    font-weight: bold;
}

This removes the need for classes or IDs on the p and h1 tags if it is applied to HTML that looks something like this:

<div id="top">
    <h1>Chocolate curry</h1>
    <p>This is my recipe for making curry purely with chocolate</p>
    <p>Mmm mm mmmmm</p>
</div>

This is because, by separating selectors with spaces, we are saying “h1 inside ID top is colour #ff0” and “p inside ID top is red and bold”.

This can get quite complicated (because it can go for more than two levels, such as this inside this inside this inside this etc.) and may take a bit of practice.