属性
只读CHARSET_RULE
CHARSET_RULE: number
只读FONT_FACE_RULE
FONT_FACE_RULE: number
只读IMPORT_RULE
IMPORT_RULE: number
只读KEYFRAME_RULE
KEYFRAME_RULE: number
只读KEYFRAMES_RULE
KEYFRAMES_RULE: number
只读MEDIA_RULE
MEDIA_RULE: number
只读NAMESPACE_RULE
NAMESPACE_RULE: number
只读PAGE_RULE
PAGE_RULE: number
只读STYLE_RULE
STYLE_RULE: number
只读SUPPORTS_RULE
SUPPORTS_RULE: number
A single CSS rule. There are several types of rules, listed in the Type constants section below.