I'm a product design student. I'm not familiar with the terminal or writing code. Please build this for me with HTML, CSS, JavaScript and native Web Audio. Make a simple, usable browser page, with no external libraries or internet services. Sound should start only after I click. Use comfortable initial levels. I need to play with the result, not read code. Make an event-timing comparison with supplied 4-second environmental events and a quiet generated background. Compare fixed waiting after each event, random waiting after each event, and start-to-start timing that can overlap. Let me choose the wait range and event, show when sounds are playing and explain the selected timing rule in one sentence. Add a calm sparse setting and a busy setting so I can hear the emotional difference, not only inspect a schedule. Global stop must cancel future events.