I found the answer from dev.to.
The reasons your code didn’t work are:
It turns out that the space-separated CSS class list that the class HTML attribute accepts is not treated as a list when calculating CSS rules precedence by the browser. The class attribute actually contains the set of classes the element has, so the order doesn’t matter.
As the order that the classes appear in the class attribute doesn’t matter, the rule that comes later in the CSS stylesheets wins.
Moreover, it wasn’t warranted that the ‘text-4xl’ was defined after the ‘text-xl’ in the CSS stylesheet.
So to solve this problem, I recommended using tailwind-merge to override previous classes.
Tailwind-merge is a utility function to efficiently merge Tailwind CSS classes in JS without style conflicts.
One of its features was: Last conflicting class wins
twMerge('p-5 p-2 p-4') // → 'p-4'