body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #000000, #000000);
    color: #f5f7fa;
    text-align: center;
    padding: 30px;
    margin: 0;
}

.contenedor {
    background: #ffffff10;
    backdrop-filter: blur(10px);
    padding: 25px 30px;
    border-radius: 16px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.4);
    display: inline-block;
    max-width: 520px;
    width: 100%;
}

h1 {
    color: #ff0000;
    margin-bottom: 20px;
}

label {
    display: block;
    margin-top: 12px;
    font-weight: 600;
    font-size: 14px;
}

select {
    width: 100%;
    padding: 10px;
    margin-top: 6px;
    background: #1c2635;
    color: #f0f3f7;
    border: 1px solid #ffe85c;
    border-radius: 8px;
    cursor: pointer;
    outline: none;
    transition: 0.3s ease;
}

select:hover {
    background-color: #263447;
}

button {
    background: #ffbd59;
    color: #1e1e2f;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 16px;
    margin-top: 20px;
    cursor: pointer;
    font-weight: bold;
    transition: background 0.3s ease;
}

button:hover {
    background: #ffa94d;
}

.resistencia {
    display: flex;
    justify-content: center;
    align-items: center;
    background: #e1e6eb;
    padding: 12px;
    margin-top: 25px;
    border-radius: 10px;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.1);
}

.banda {
    width: 16px;
    height: 64px;
    margin: 0 6px;
    border-radius: 5px;
    transition: background-color 0.3s ease;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

#resultado {
    font-size: 18px;
    margin-top: 20px;
    font-weight: bold;
    background: #ffffff20;
    padding: 12px;
    border-radius: 8px;
    color: #e8ecf0;
    box-shadow: inset 0 0 5px rgba(255, 255, 255, 0.1);
}