It’s a bit funny that it’s completely at odds with how they describe their goals (emphasis mine):

I am thereallo, a web developer who makes things look pretty and work smoothly >w< been building stuff since 2020, mostly frontend but i can do fullstack too! i use react, next.js, and tailwind css because they just work, and motion for animations that don’t feel plastic. i prototype in figma, steal components from shadcn/ui when i’m lazy, and deploy to vercel or cloudflare depending on the vibe~ i used to reverse engineer games (genshin leaks era lol) but now i just make websites that don’t suck. i know typescript, python, go, and dabbled in rust and lua. my goal is making ui that feels human such as smooth feedback, clear buttons, keyboard accessible, no confusing bs. mobile first always! outside coding i listen to vocaloid and play project sekai, which definitely influences my color choices uwu. oh and i care way too much about bundle sizes and performance. currently learning native ios/android development. hmu on discord or github if u wanna chat! ♡

Holy shit, i thought i was gonna have a seizure first time i scrolled

Yea for me too, it appears to be something we the title header following your scroll. It’s super smooth just until it tries to pin it to the top.

Reader mode works until I realised that they did explain the pictures, so just referenced text I didn’t see.

Not a performance problem. My guess is, they (poorly) emulate native scrolling via JS on mobile. Probably for some progress feature or something.

JS disabled, scrolling works. Though it was only slightly laggy for me.