Why do I get the styles of others .css files to React?

I have a routing

Each component has its own .css file with styles. In the component Search is and the class 'tag' not in style .css file, at the same time, exactly the same div is in the component Playlist, but in .this component have css styles for the class 'tag', somehow miraculously I get from the component Search styles from the component Playlist. Tell us what the secret is and what to do, and wildly uncomfortable. Thank you