<div class="px-12">
<button type="submit"
class="flex w-full justify-center rounded-md bg-indigo-600 px-3 py-1.5 mt-8 text-sm">
Войти
</button>
<button type="submit"
class="flex w-full justify-center rounded-md bg-indigo-600 px-3 py-1.5 my-4 text-sm">
Регистрация
</button>
</div>
если поставить px-12 больше 12