When a user agent can't parse the selector, it must ignore the declaration block as well.

当一个用户代理不能解析某个选择器的时候，它必须忽略整个声明块。

youdao

A CSS rule consists of a selector and a declaration block.

CSS规则由一个选择符和一个声明块组成。

youdao

You can reduce this font size by assigning 62.5% to the font-size property of the body selector (also known as the block-level element) like shown in Listing 2.

通过为正文选择器（body selector，也称为块级元素）的 font-size 属性分配 62.5% 的值可以减小这个字体大小，如清单 2 所示。

youdao