size: P / 15 height: 19 / P margin: Q / P h1: 24px h2: 14px h1: size: 24 / 15 = 1.6em height: 19 / 24 = 0.79167em margin: @@ h2: size: 14 / 15 = 0.9333em height: 19 / 14 = 1.3571em margin: @@ p: size: 1em line-height: 19 / 15 = 1.2667em h2: size: 13 / 15 = 0.8667em height: 19 / 13 = 1.4615em margin-top: 27 / 13 = 2.0769em margin-bottom: 9 / 13 = 0.6923em size: 12 / 15 = 0.8em height: 19 / 12 = 1.5833em margin-top: 27 / 12 = 2.25em margin-bottom: 9 / 12 = 0.75em h2 { font-family: "Lucida Grande", Helvetica, sans-serif; font-weight: bold; font-size: 0.8em; line-height: 1.5833em; margin-top: 2.25em; margin-bottom: 0.75em; } font-size: 0.9333em; line-height: 1.3571em; margin-top: 1.929em; margin-bottom: 0.643em; h1: size: 25 / 15 = 1.6667em height: 19 / 25 = 0.76em margin: @@ font-size: 1.6em; line-height: 0.79167em; margin: 0 0 1.6em 0; 1.6 * 15 32 / 25