Am I mistaken in believing that the <details> element is not a block level element?

Question

I want to know for sure if <details>- a block level element. The reason I ask is this:

• MDN has a "complete" list for all block level elements, but is <details>not in the list.
• The W3C specification in this element does not mention that it is a block level element
• Same as # 2, but for MDN a resource
• Same as # 2 for the W3C HTML5 Specification

and

5. The specification in No. 3 has code for <details>. When you open this Codepen in Firefox (54.0.1) and check the element <details>, it is inline, but when you open the same Codepen in Chrome (59.0.3071), the same element is set as blockon the User Agent table.

Is the element <details>inline or blocky or browser dependent?

Answer 1

An element <details>behaves like a block level element. To check this, I opened jsfiddle, added an element <details>and inspected it. I was also able to set it to the line just fine.

Microsoft Edge , .

EDIT: Firefox, Firefox , .

Answer 2

- :

<span><details></details></span>

... W3C HTML Validator :

details , span .

, details:
    .
span:
    .

, , .

, / HTML, . HTML5, CSS3 , .