从html中的父css类中逃脱

I'm working with an HTML template that has its own CSS and is quite extensive. It has over 2,000 lines of code. I want to put an input text with a button inside a form, but this form has a CSS class, since I don't want to modify the existing CSS class just for one button, is there a way to put an HTML element inside a form with a CSS class, such that the CSS class doesn't affect my HTML element? Are there any special HTML tags which I could use to put other elements inside element which wouldn't be affect by the CSS of the parent?I'm working with an HTML template that has its