URGENT: Simple One Page Web App

I need a simple one page web app that will allow users to play multiple sounds at the same time and these sounds will play as single files so user can pause any of these sounds anytime and play the others. Also users will be able to save a collection of current playing sounds as a saved mix so they can come back anytime to the website and play them. When users load any of their saved mixes, the sounds in this mix will just play with each other.

There is no user registration but we will use cookies in the meantime to remember users so they can come back anytime and find their playing sounds, saved mixes and timer settings.

We need to use VANILLA HTML, CSS and Javascript so no need to use any frameworks like bootstrap, jquery or vue js. Responsive design can be done with CSS grid or flexbox.

Here is a link to finished design: https://www.figma.com/proto/ZFwg9MMa0xuk1ocEGLNpGJ/SoundLove?node-id=255%3A2&scaling=scale-down-width&page-id=0%3A1

Here is an animated prototype with different design that explains the idea https://www.dropbox.com/s/7ac1kgdsdzc989z/Screen%20Recording%202021-08-22%20at%201.46.46%20PM.mov?dl=0

Please let me know any estimated time to finish this project so I can consider your application.