Function parse_edges 

pub fn parse_edges(
    ctx: &str,
    name: &str,
    value: &str,
) -> Result<Edges, ParseError>

Parse a CSS-style spacing shorthand, top-right-bottom-left.

• 1 value n -> every side n.
• 2 values v h -> top/bottom = v, left/right = h.
• 3 values t h b -> top, left/right, bottom.
• 4 values t r b l -> explicit per-side.

Each term is <n> / <n>px / <n>% - percent terms land in the pct_* fields and resolve per CSS at layout time.