CSS controls presentation: colors, spacing, type and layout. Start with the cascade, then size a component, then test it at narrow widths and high zoom.
Start here
- CSS selectors and the cascade: trace the winning declaration
- CSS box model and layout: size content without accidental overflow
- Responsive CSS: keep reading order and controls usable
Use HTML with it
CSS changes appearance, not document meaning. Build the structure in HTML and use Web Development to connect markup, styles and behavior.
Common Mistakes
A page that only looks correct at one width is not finished. Check reading order, contrast, zoom and long content.