<span style="color: #21584b;"><p>Text</p></span>
That's an example of some code I have in my website. The colour is a dark green and it displays normally on my PC as well as on my Android phone. But, when viewed on an iPhone or an iMac the text is within the <p> tag appears white. I don't have any CSS in the stylesheet targeting just a <p> or a <span>. All of the CSS in the stylesheet has an additional class or an id.
I've removed the <span> tags wrapping the <p> one, but I have no way of testing it since I don't own any Apple devices myself.
So, the question is, will elements inherit inline CSS, like I've put here if they don't have any classes or ids overriding them?
<p>is not a valid child of<span>so chances are some browsers are "correcting" your invalid HTML and the result is not what you expect.