CSSImportRule：href 属性
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since 2015年7月.
CSSImportRule 接口的只读属性 href 返回由 @import at 规则指定的 URL。
解析后的 URL 将是关联样式表的 href 属性。