1.9 KiB
selector-pseudo-element-colon-notation
Specify single or double colon notation for applicable pseudo-elements.
a::before { color:pink; }
/** ↑
* This notation */
The :: notation was chosen for pseudo-elements to establish a discrimination between pseudo-classes (which subclass existing elements) and pseudo-elements (which are elements not represented in the document tree).
However, for compatibility with existing style sheets, user agents also accept the previous one-colon notation for pseudo-elements introduced in CSS levels 1 and 2 (namely, :first-line, :first-letter, :before and :after).
Options
string: "single"|"double"
"single"
Applicable pseudo-elements must always use the single colon notation.
The following patterns are considered warnings:
a::before { color: pink; }
a::after { color: pink; }
a::first-letter { color: pink; }
a::first-line { color: pink; }
The following patterns are not considered warnings:
a:before { color: pink; }
a:after { color: pink; }
a:first-letter { color: pink; }
a:first-line { color: pink; }
input::placeholder { color: pink; }
li::marker { font-variant-numeric: tabular-nums; }
"double"
Applicable pseudo-elements must always use the double colon notation.
The following patterns are considered warnings:
a:before { color: pink; }
a:after { color: pink; }
a:first-letter { color: pink; }
a:first-line { color: pink; }
The following patterns are not considered warnings:
a::before { color: pink; }
a::after { color: pink; }
a::first-letter { color: pink; }
a::first-line { color: pink; }
input::placeholder { color: pink; }
li::marker { font-variant-numeric: tabular-nums; }