Js-ineffective solution for adding style to pages

I encountered a problem when I was working on the project today. jsp introduces B. jsp, c. jsp also introduces B. jsp, while B. the style in jsp is dynamically changed according to the introduced differences (in. jsp, c. js changes written in jsp ). I found a lot of code on the Internet and tried it many times, but it didn't work. Later, I saw this code, document. getElementById ("aa" ).style.css Text = "background: #1175d9;"; (you can add the style you need in cssText = "" quotes) to solve my problem.