who is proficient in vue, teach me how to control the elements of child routing.
case is: two links title 1, title 2, click to display content 1, content 2; then, content 1 has two links: title 11, title 22, click title 11 to add a border to him, display content 11; click title 22 title 11 border to disappear title 22 plus border to display content 22; click on the element in content 22 to change the color of the word; finally, click on the content in content 2 to change the background color.