How to align content of a div to the bottom

Answer 1

if you could set the height of the wrapping div of the content (#header-content as shown in other's reply), instead of the entire #header, maybe you can also try this approach:

HTML

    
some title
    

        
            first line of header text

            second line of header text

            third, last line of header text
        
    

CSS

#header-content{
    height:100px;
}

#header-content::before{
  display:inline-block;
  content:'';
  height:100%;
  vertical-align:bottom;
}

#header-content span{
    display:inline-block;
}

show on codepen