形式语法 <compositing-operator>#where<compositing-operator>=add|subtract|intersect|exclude 例子 CSS #masked
形式语法 <masking-mode>#where<masking-mode>=alpha|luminance|match-source 例 CSS内容 #masked{width:227px;height
<length-percentage>=<length>|<percentage> 例子 CSS内容 #masked{width:100px;height:100px;background-color:
length-percentage>=<length>|<percentage> 例 CSS #wrapper{border:1pxsolidblack;width:250px;height:250px;}#masked
stroke-box|view-boxwhere<shape-box>=<box>|margin-boxwhere<box>=border-box|padding-box|content-box 例 CSS内容 #masked
stroke-box|view-boxwhere<shape-box>=<box>|margin-boxwhere<box>=border-box|padding-box|content-box 例子 CSS内容 #masked
repeat-style>#where<repeat-style>=repeat-x|repeat-y|[repeat|space|round|no-repeat]{1,2} 实例 单值 CSS内容 #masked
<length-percentage>|auto]{1,2}|cover|containwhere<length-percentage>=<length>|<percentage> 例 CSS内容 #masked