016 Heartbeat Line

1 test · 11 finished runs (0 agent, 11 raw one-shot) · 11 live demos

The prompt

Heartbeat Line: A live ECG-style monitor that scrolls a heartbeat trace across a dark grid, with a BPM readout, a slider from 40 to 180 BPM that changes the rhythm in real time, a red flash on each beat, and an optional synthesised beep per beat. Build it as ONE self-contained HTML file: inline CSS and JavaScript only, no libraries or frameworks, and no external requests of any kind (no CDNs, web fonts, images or audio files); anything visual or audible is made in code (HTML/CSS, SVG, Canvas, WebGL or WebAudio). It must work when opened directly from disk, fit the browser window responsively, and run without console errors. Output ONLY the complete HTML file, starting with <!DOCTYPE html> and ending with </html>, with no explanation or markdown fences.