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 a noise listening app. Generate white, pink and brown noise in the browser with Web Audio and JavaScript, without downloading sound files. Give me a type selector, on/off and level. I want to switch colours at comfortable, comparable levels, without effects. Switching must not stack extra sources. Add a simple spectrum so I can see the different frequency balance. Explain in one short line what to listen for in each noise.