What are the default CSS styling of heading tags? (H1, h2, h3, h4, h5)

Question

In HTML, headings are denoted with (1,2,3,4,5,6) tag.

My question is regarding following HTML code:

Answer 1

Question: is there predefined property for same in CSS?

No

You can try like this:

h3{ 
   display: block; 
}

h3 {
   font-size: /*Font size similar to h3*/ ;
}