I'll first check the current directory to see what's present, particularly tone.min.js. Then I'll create a self-contained index.html with CSS and JS that uses Tone.js. Let's start.

Great! tone.min.js is present. Now I need to create index.html with a piano keyboard, using Tone.js for synthesis. The piano should have visual key feedback for mouse and keyboard, use ADSR envelope, and be fully self-contained.

Let me first check the Tone.js version to understand the API.

I'll assume the latest Tone.js API (likely version 14.x or 15). I'll use Tone.Synth with envelope parameters. I'll create a keyboard with 24 keys (2 octaves) or maybe 3 octaves. Let's do 3 octaves from C4 to C7 (36 keys). White keys are rectangles, black keys are smaller and positioned above.

We'll map computer keys to piano keys (like A, S, D, F, G, H, J, K, L, ;, ', etc.). We'll also handle mouse clicks.

We'll need to handle note on/off with envelope release. Use Tone.Transport to schedule? Actually, synth.triggerAttackRelease.

Let's design the HTML structure. We'll have a container for piano, inside white and black keys with data-note attributes.

CSS: position relative for container, absolute for black keys.

JS: Initialize Tone context, create synth, map keydown/keyup events to note triggers, and mouse events.

We'll also include a simple ADSR control panel with sliders.

Let's write the entire index.html. I'll do it step by step, but finally write the whole file.

First, let's create a skeleton and then fill in details. Let's write the file now.

Probably okay. I'll assume Tone.Synth with envelope options.

Now I'll write the index.html file. I'll include:

- HTML structure for piano keys (white and black)
- CSS for styling, with hover, active states
- JavaScript to initialize Tone context, map keyboard keys to notes, handle mouse events, create synth with ADSR, play notes with visual feedback.

I'll make the piano span at least two octaves (C4 to C6 maybe). Map computer keys to piano keys (ASDFGHJ for white keys, WETYU for black keys). Use Tone.Synth with envelope parameters.

Let's create the file.

I'll need to know the basic usage. Since we have the global Tone, we can use Tone.Synth with ADSR envelope, Tone.Transport for timing maybe, and Tone.start() for user interaction.

Let's create the HTML file with inline CSS and JS.

I'll write the content step by step.

First, I'll create a basic structure: html, head, body, div for piano keys, script tag for Tone (src="tone.min.js") and then our own script.

I'll design a piano with 24 keys (2 octaves) for simplicity. White keys: 7 per octave, black keys: 5 per octave. Map computer keys to notes (e.g., a,s,d,f,g,h,j for white keys, w,e,t,y,u for black keys). Also mouse clicks.

Use ADSR envelope: attack, decay, sustain, release. Provide sliders for envelope controls.

Visual feedback: key down changes color.

Let's start writing the file.

Probably the minified version. I'll rely on typical Tone.js API: Tone.Synth with envelope, Tone.Transport, etc. I'll create a simple piano with white and black keys, map mouse events, and map computer keyboard keys (like a, s, d, f, g, h, j for white keys, w, e, t, y, u for black keys). Use ADSR envelope parameters.

Let's write the index.html file. I'll do it in one go.