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<!DOCTYPE html> <html> <head> <style> /* 默认的 CSS 值 */ q { display: inline; } q:before { content: open-quote; } q:after { content: close-quote; } q.customized:before { content: "- "; } </style> </head> <body> <p>默认情况下，q 元素会这样显示：</p> <q>Build a future where people live in harmony with nature.</q> <p>自定义的 q 元素（更改 content）：</p> <q class="customized">Build a future where people live in harmony with nature.</q> </body> </html>
运行结果
