Module css 

CSS subset parser for EPUB styling

Parses a minimal subset of CSS sufficient for EPUB rendering:

• Font properties: font-size, font-family, font-weight, font-style
• Text: text-align, line-height, letter-spacing
• Spacing: margin-top, margin-bottom
• Selectors: tag, class, and inline style attributes

Complex selectors, floats, positioning, and grid are out of scope.

Structs

CssRule

A single CSS rule (selector + declarations)

CssStyle

A set of CSS property values

Stylesheet

A parsed CSS stylesheet

Enums

CssSelector

A CSS selector (subset)

FontSize

Font size value

FontStyle

Font style

FontWeight

Font weight

LineHeight

Line height value

TextAlign

Text alignment

Functions

parse_inline_style

Parse an inline style attribute value into a CssStyle

parse_stylesheet

Parse a CSS stylesheet string into a Stylesheet