nl_tokens: ie10以及以下，对某些样式支持有问题，需要降级
pl_tokens: function getIEVersion ( ) { var agent = navigator . userAgent var reg = / MSIE\s?(\d+)(?:\.(\d+))? / i var matches = agent . <mask> ( reg ) if ( matches != null ) { return { major : matches [ 1 ] , minor : matches [ 2 ] } } return { major : '-1' , minor : '-1' } }