选择器前的CSS空间

I was struggling to understand why this simple CSS class selector was not being picked by my HTML element..label-hi :before { color:green; content: "Hi ! ";} 解决方案 The space between simple selectors is a descendant combinator in CSS. If it were two ordinary selectors separated with space, it would mean 'element matching the second selector, placed anywhere inside the element matching the first selector'. Since the second selector is a pseudo element, the whole selector is equivalent to .label-hi *:before, potentially inserting something into any element inside the element with class label-hi. 这篇关于选择器前的CSS空间的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！