Target specific browsers CSS


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Hi – I have an intro paragraph with a drop cap. The CSS selector ::first-letter works fine in all browsers except Firefox, where the styling is a little off.

So, I try adding this @rule to the Selector, in the Code section, however, a warning shows saying this rule is unknown. If I click into another selector and back into the ::first-letter selector, that @rule then disappears.

@-moz-document url-prefix() {
article:nth-of-type(1) p:nth-of-type(1)::first-letter {
margin-top: 7px;


If I add this @rule to another external style sheet, it works.

Thanks. Gavin.


Okay, I’ve found a solution by using View > Full Code Editor. This works, but a warning/flag ‘Unknown @ rule: @moz-document.’ is still present.


Hi Gavin,

Well done for finding a solution with the full code editor. The other code editor only allows regular selector code.

I’ve just released version, which should remove the warning flag from the code editor. You may need to do a hard refresh / cache clear if the warning icons still shows.



Cheers – that was quick 🙂

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