<!DOCTYPE html> <html> <head> <style type="text/css"> .separator { height: 20px; background-color: green; } #min-height { font-size: 15px; line-height: 1; min-height: 0; height: auto; margin-top: 20px; margin-bottom: 20px; } </style> </head> <body> <div class="separator"></div> <div id="min-height"> </div> <div class="separator"></div> </body> </html>