Use the CSS :empty selector to style every <p> element that has no children with CSS. You can try to run the following code to implement the :empty selector −
Example
<!DOCTYPE html> <html> <head> <style> p.demo { width: 300px; height: 20px; background: gray; } p:empty { width: 150px; height: 20px; background: orange; } </style> </head> <body> <p class = "demo">This is demo text. Below is empty text.</p> <p></p> </body> </html>