The code for cssCollapse.html is: <!DOCTYPE html> <html lang="en"> <head> <title>CSS collapse</title> <meta charset="utf-8"> <style> div { margin: 2rem 0; background: lavender; } p { margin: 0.4rem 0 1.2rem 0; background: yellow; } </style> </head> <body> <h1>CSS collapse</h1> <p>The bottom margin of this paragraph is collapsed …</p> <p> … with the top margin of this paragraph, yielding a margin of <code>1.2rem</code> in between. </p> <div> This parent element contains two paragraphs! <p> This paragraph has a <code>.4rem</code> margin between it and the text above. </p> <p> My bottom margin collapses with my parent, yielding a bottom margin of <code>2rem</code>. </p> </div> <p>I am <code>2rem</code> below the element above.</p> </body> </html>