iawia002/lux ? reverse-engineered prompt

Build me a fast, simple command line video downloader in Go like Lux.

I want to paste in one or more video URLs and have it figure out the site, show me the available quality options, and download the one I pick. It should also handle playlists, let me download a range of items, resume broken downloads, retry if something fails, and read URLs from a file too. If the link is to a direct file like an image or something else, it should still try to download it directly.

Please make it work with common video sites like YouTube, bilibili, Youku, iQiyi, QQ, Tumblr, and similar ones, and support things like cookies, proxy settings, custom referrer, and choosing the output name and folder. If FFmpeg is needed to merge audio and video at the end, wire that in too. Keep the interface simple and friendly, with clear status output while downloading. If you need to look up current site behavior or docs online, do that.