Details

Operators should be formatted with a single space on both sides of an infix operator. These include +, -, *, /, %, ==, !=, >, >=, <, and <=.

Bad: no space around operator

margin: 5px+5px;

Bad: more than one space around operator

margin: 5px   +   5px;

Good

margin: 5px + 5px;

Note that this linter only applies to actual, evaluated operators. So values like nth-child(2n+1), 10px/12px, and my-font will not be linted, as they are valid CSS.

The style option allows you to specify a different preferred style.