# One-Shot Audio Lab: Browser-Native Sequencer Workstation

Create a single-file, browser-native 16-step sequencer and synth workstation using HTML, CSS, and Vanilla JavaScript with the Web Audio API. No external assets or libraries are allowed.

## System Floor Requirements

- **Three Audio Voices**: Implement 3 distinct synthesized voices: a Kick drum, a Snare drum, and a Synth Bass. Use Web Audio oscillators and envelopes.
- **16-Step Sequencer**: An interactive grid for each of the three voices, allowing the user to toggle notes on and off.
- **Transport Controls**: Play, Stop, and Clear buttons. A Tempo slider (BPM) that smoothly updates the playback speed.
- **Mixer Section**: Individual volume knobs or sliders for each voice, plus mute/solo toggles if possible.
- **Visual Feedback**: The sequencer steps must light up as the playhead passes over them. Provide a master visualizer (like an oscilloscope or spectrum analyzer) using an HTML5 Canvas hooked into an `AnalyserNode`.

## Quality and Aesthetic Bar

- **Tactile UI**: Design the interface to feel hardware-like. Use large, clickable grid pads, clear knobs/sliders, and a cohesive, high-contrast dark theme (e.g., a "Nocturnal Dub Tape Deck" aesthetic with glowing accents).
- **Responsive & Performant**: Use strict scheduling in the Web Audio API (lookahead/scheduling loop) so playback stays tight and rhythmic regardless of UI thread load.
- **Mobile Friendly**: Ensure the step grid and controls are easily tappable on mobile devices.
- **Interaction Requirement**: Include an explicit "Power On" or "Start" overlay to unlock the Web Audio context according to modern browser autoplay policies.

Output exactly one complete HTML file containing all logic, styles, and markup.