Assessement and Code Feedback for ES6 Javascript

Hello Everybody ,

I need some assessement on the App , I have developed . It is a simple Audio Player .
Audio files should be added to Song folder . Simiarliy SONGPATH array should be updatedin Index.js with fileNames

Please provide your feeback on Javascript Code and Css design . I am trying improve my frontend skills

Codepen link : https://codepen.io/uparthiban/project/editor/ZdRQrv#0