Is it possible to put CSS @media rules inline?

@media at-rules and media queries cannot exist in inline style attributes as they can only contain property: value declarations. As the spec puts it:

The value of the style attribute must match the syntax of the contents of a CSS declaration block

The only way to apply styles to one specific element only in certain media is with a separate rule in your stylesheet (be it linked externally or internally in a <style> element), which means you'll need to come up with a selector for it. You can grab one using your browser's dev tools, or figure out a class and/or ID combination that isolates this element:

#myelement { background-image: url(particular_ad.png); }

@media (max-width: 300px) {
    #myelement { background-image: url(particular_ad_small.png); }
}

If you're unable to find a selector that will reliably match this element alone due to the nature of your page, you can use a custom property, provided you don't need to worry about specificity or Internet Explorer:

:root { --particular-ad: url(particular_ad.png); }

@media (max-width: 300px) {
    :root { --particular-ad: url(particular_ad_small.png); }
}

<span style="background-image: var(--particular-ad);"></span>

Problem

No, Media Queries cannot be used in this way 

<span style="@media (...) { ... }"></span>

Solution

But if you want provided a specific behavior usable on the fly AND responsive, you can use the style markup and not the attribute.

e.i.

<style scoped>
.on-the-fly-behavior {
    background-image: url('particular_ad.png'); 
}
@media (max-width: 300px) {
    .on-the-fly-behavior {
        background-image: url('particular_ad_small.png');
    }
}
</style>
<span class="on-the-fly-behavior"></span>

See the code working in live on CodePen

In my Blog for example, I inject a <style> markup in <head> just after <link> declaration for CSS and it's contain the content of a textarea provided beside of real content textarea for create extra-class on the fly when I wrote an artitle.

Note : the scoped attribute is a part of HTML5 specification. If you do not use it, the validator will blame you but browsers currently not support the real purpose : scoped the content of <style> only on immediatly parent element and that element's child elements. Scoped is not mandatory if the <style> element is in <head> markup.

UPDATE: I advice to always use rules in the mobile first way so previous code should be:

<style scoped>
/* 0 to 299 */
.on-the-fly-behavior {
    background-image: url('particular_ad_small.png'); 
}
/* 300 to X */
@media (min-width: 300px) { /* or 301 if you want really the same as previously.  */
    .on-the-fly-behavior {   
        background-image: url('particular_ad.png');
    }
}
</style>
<span class="on-the-fly-behavior"></span>

Tags:

Html

Css

Media Queries

Recent Posts