body {
    font-family: Arial, sans-serif;
    background: #eef2f7;
    margin: 0;
    padding: 0;
}

.contenedor {
    max-width: 520px;
    margin: 50px auto;
    background: white;
    padding: 35px;
    border-radius: 18px;
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.12);
    text-align: center;
}

h1 {
    color: #1f3c88;
    margin-bottom: 25px;
}

label {
    display: block;
    font-weight: bold;
    margin-top: 15px;
    margin-bottom: 6px;
}

input,
select {
    width: 100%;
    padding: 12px;
    font-size: 15px;
    border: 1px solid #c7cdd6;
    border-radius: 8px;
    box-sizing: border-box;
}

button {
    background: #1f3c88;
    color: white;
    border: none;
    padding: 12px 18px;
    margin: 18px 6px 10px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: bold;
}

button:hover {
    background: #162d66;
}

#resultado {
    margin-top: 20px;
    padding: 18px;
    background: #edf5ff;
    border-radius: 12px;
    line-height: 1.7;
}

.explicacion {
    margin-top: 25px;
    padding: 18px;
    background: #f8fafc;
    border-radius: 12px;
    text-align: left;
}

.explicacion h3 {
    text-align: center;
    color: #1f3c88;
}

.explicacion p {
    font-size: 14px;
    line-height: 1.5;
}

@media (max-width: 600px) {
    .contenedor {
        margin: 20px;
        padding: 25px;
    }

    button {
        width: 100%;
        margin: 10px 0;
    }
}