Comment by solardev
Seconding this. It's one of the best resources I've seen and easily worth the money.
frontendmasters.com and LinkedIn Leaning also have good video courses.
Also see MUI.com as a nice way to structure a component framework.
Beyond that, work with a good designer, make Figmas before you code, test out the flows, iterate it, and then throw everything away and do it again 2 years later when fashions change (sigh).
A lot of what we see as good/modern design is just fashion cycles of designers stealing from each other. For a while everything looked like Yahoo, then everything looked like Google, then everything looked like Bootstrap, and now everything looks like Tailwind/Vercel. It's the designer equivalent of Stackoverflow.