In laying out a web design, I often try to make sure that my typography is proportional and consistent. However, I haven't been able to find any definitive articles or resources on what ratios and sizes should be used. Specifically, what are the recommended or standard practices for:
- Font-size
- Line-height
- Line-width
- Line-spacing
Please consider both paragraph and header text in your answers. Also, any studies on the effectiveness of various ratios or metrics would be very useful.