Child margin adding margin to parent

Question

how if i have the following code : HTML :

    
Hello

         


        

Answer 1

http://jsfiddle.net/naeemshaikh27/qbaucv3j/1/

  .main{
        overflow: hidden; 
        height: 100%;
        background: pink;
    }

This is normal behaviour (among browser implementations at least). Margin does not affect the child's position in relation to its parent, unless the parent has padding, in which case most browsers will then add the child's margin to the parent's padding.

source https://stackoverflow.com/a/1939980/3556874