Selected preset buttons looked identical to unselected in dark mode: the
override classes `border-foreground bg-foreground/5` carry no `dark:`
variant, while the Button `outline` variant base contains
`dark:border-input dark:bg-input/30`. tailwind-merge keeps both (different
variants → no conflict), and in dark mode CSS specificity makes
`.dark .border-input` win over `.border-foreground`, so the override is
silently overridden and the bright-border/tinted-bg selection state never
applies.
Add explicit `dark:border-foreground dark:bg-foreground/10` to the
override so tailwind-merge resolves the dark-variant conflict in favor
of the override and the selected state is clearly distinguishable on
both light and dark backgrounds.
Co-authored-by: xinnyu <xinnyu@users.noreply.github.com>
