body {
    font-family: Arial, Helvetica, sans-serif;
    background: linear-gradient(135deg, #4e73df, #1cc88a);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.contenedor {
    background: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0px 10px 25px rgba(0,0,0,0.2);
    width: 350px;
    text-align: center;
}

h2 {
    margin-bottom: 20px;
    color: #333;
}

input[type="number"] {
    width: 90%;
    padding: 10px;
    margin: 8px 0;
    border-radius: 8px;
    border: 1px solid #ccc;
}

input[type="submit"] {
    width: 100%;
    padding: 10px;
    border: none;
    border-radius: 8px;
    background-color: #4e73df;
    color: white;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
}

input[type="submit"]:hover {
    background-color: #2e59d9;
}

.resultado p {
    text-align: left;
    margin: 8px 0;
}