I have some HTML that would have elements with multiple classes, and I need to assign them within one rule, so that the same classes could be different within different containers. Say I have this in my CSS:
.border-blue {
border: 1px solid blue;
}
.background {
background: url(bg.gif);
}
Then I have this in my HTML:
<div class='border-blue background'>Lorum Crap No-one Cares About Ipsum</div>
Can I target these within a single rule? Like this, for example, which I know doesn't work:
.border-blue, .background {
border: 1px solid blue;
background: url(bg.gif);
}
2 Answers
.border-blue.background { ... }is for when both classes are used together..border-blue, .background { ... }is for either class..border-blue .background { ... }is for where '.background' is the child of '.border-blue'.
See Chris' answer for a more thorough explanation. Also see W3 Docs on CSS Combinators
Just in case someone stumbles upon this like I did and doesn't realise, the two variations above are for different use cases.
The following:
.blue-border, .background {
border: 1px solid #00f;
background: #fff;
}
is for when you want to add styles to elements that have either the blue-border or background class, for example:
<div class="blue-border">Hello</div>
<div class="background">World</div>
<div class="blue-border background">!</div>
would all get a blue border and white background applied to them.
However, the accepted answer is different.
.blue-border.background {
border: 1px solid #00f;
background: #fff;
}
This applies the styles to elements that have both classes so in this example only the <div> with both classes should get the styles applied (in browsers that interpret the CSS properly):
<div class="blue-border">Hello</div>
<div class="background">World</div>
<div class="blue-border background">!</div>
So basically think of it like this, comma separating applies to elements with one class OR another class and dot separating applies to elements with one class AND another class.
