w3.org上默认使用duckduckgo搜索引擎，查找站点内容可以使用这样到方式：比如搜索 white-space：
https://duckduckgo.com/?q=site%3Aw3.org+white-space&search-submit=&ia=web
CSS知识点补充如下：
white-space https://www.w3.org/TR/css-text-3/#white-space-property white-space的可能值
normal | pre | nowrap | pre-wrap | break-spaces | pre-line。display https://www.w3.org/Talks/2003/0521-CSS-WWW2003/inline-demo.html 图片在一行显示 display:inline-block;
transition https://www.w3.org/TR/css-transitions-1/ CSS Transitions allows property changes in CSS values to occur smoothly over a specified duration. to animate smoothly from the old state to the new state over time. https://www.cnblogs.com/afighter/p/5731293.html ease 由快到慢到更慢 linear:恒速 ease-in:越来越快 ease-out:越来越慢 ease-in-out:先加速后减速 transition:ease 0.5s;