When you click Render, FFmpeg mixes all lanes into per-clip final MP4 files, then optionally concatenates them into one master video — with word-by-word captions burned in. auto_stitch/ ├── app/ │ ├── ...
50% {transform:translateY(-25px) rotate(8deg) scale(1.05);} 100% {transform:translateY(0px) rotate(0deg) scale(1);} ...