.titulo {
    float: left;
    padding: 1%;
    color: white;
    background-color: silver;
    width: 800px;
    border: 5px solid red;
    text-align: center;
    margin-bottom: 10px;
}

.formulario {
    float: left;
    padding: 1%;
    color: white;
    background-color: mediumaquamarine;
    width: 800px;
    border: 5px solid red;
    text-align: left;
}

.resultado {
    float: left;
    margin-top: 15px;
    width: 800px;
    background-color: darkslategray;
    color: white;
    border: 3px solid black;
    padding: 10px;
    font-size: 18px;
    border-radius: 6px;
}


button {
    margin-right: 10px;
}

body {
    display: flex;
    flex-direction: column;
    align-items: center;
}