I thought this was an unhinged parody of a design site, kinda surprised it's a real thing. Unfortunately the design isn't for me, things look off center and the overall "weight" of components feels off.
I hate to pile on since it's already getting some criticism, but I agree. It's kind of a good example why designers don't purely rely on mathematically consistent designs. Getting things to "look right" often means shifting pixels here and there ever so slightly, so that the math is a bit off but it feels better on the eyes.
Yeah I tried using a similar "golden rule" after reading a design article about it. I based my css variable sizes on it but I kept having to use manual px and rem values instead because stuff just never felt correct.
1.618 is complete nonsense that people hang on to because they want it to be true. It doesn't stack up, neither in ancient Greek times, nor in the renaissance, nor today. It's a dumb idea that needs to die.