from tkinter import *
root = Tk()
root.geometry("400x300")
root.resizable(0, 0)
root.config(bg="#096e75")
root.title("Antecessor e Sucessor")

titulo = Label(text="Antecessor e Sucessor ",
               font=("Arial", "25", "bold"),bg="#096e75",fg="#05e8ab")
titulo.place(relx=0.05, rely=0.05)
texto_sub1  = Label(text="Número:",
                    font=("Arial", "15", "bold"),bg="#096e75",fg="#05e8ab")
texto_sub1.place(relx=0.15, rely=0.3)

Número = IntVar()
Número_entrada = Entry(textvariable=Número,
                             font=("Arial", "12", "bold"),
                             bg="white", fg="blue", justify='center')
Número_entrada.place(relx=0.55, rely=0.3, relwidth=0.2)
def limpar():
    Número_entrada.delete(0, END)
    resultado.set("")
def app():
    n = Número.get()
    antessor = n-1
    sucessor = n+1
    mensagem = f"Antecessor de {n}: {antessor}\nSucessor de {n}: {sucessor}"
    resultado.set(mensagem)
but1 = Button(text="Calcular", bd=2, bg='#107db2', fg='white',
              font=('verdana', 12, 'bold'), command=app)
but1.place(relx=0.05, rely=0.5, relwidth=0.25, relheight=0.1)
but_limpar = Button(text="Limpar", bd=2, bg='#107db2', fg='white',
                    font=('verdana', 12, 'bold'), command=limpar)
but_limpar.place(relx=0.35, rely=0.5, relwidth=0.25, relheight=0.1)

but_sair = Button(text="Sair", bd=2, bg='#107db2', fg='white',
                    font=('verdana', 12, 'bold'), command=root.destroy)
but_sair.place(relx=0.65, rely=0.5, relwidth=0.25, relheight=0.1)

resultado = StringVar()
resultado_texto = Label(textvariable=resultado,
                           font=("Arial", 12, "bold"), bg="#cfe2f3")
resultado_texto.place(relx=0.05, rely=0.65, relwidth=0.9,relheight=0.3)
root.mainloop()