body {
    font-family: 'Arial', sans-serif;
    background-color: #F4F4F4;
    color: #333;
    text-align: center;
    padding: 20px;
}

.contenedor {
    background: #FFFFFF;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    display: inline-block;
    max-width: 500px;
    width: 100%;
}

h1 {
    color: #555;
    font-size: 22px;
    margin-bottom: 15px;
}

label {
    display: block;
    margin-top: 10px;
    font-weight: normal;
    color: #444;
    font-size: 14px;
}

select {
    width: 100%;
    padding: 8px;
    margin-top: 5px;
    background: #F9F9F9;
    color: #333;
    border: 1px solid #CCC;
    border-radius: 4px;
    cursor: pointer;
    outline: none;
    transition: background 0.2s;
}

select:hover {
    background: #EDEDED;
}

button {
    background: #888;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 4px;
    font-size: 14px;
    margin-top: 10px;
    cursor: pointer;
    transition: background 0.2s;
}

button:hover {
    background: #777;
}

.resistencia {
    display: flex;
    justify-content: center;
    align-items: center;
    background: #DDD;
    padding: 8px;
    margin-top: 15px;
    border-radius: 6px;
    position: relative;
}

.banda {
    width: 12px;
    height: 50px;
    margin: 0 4px;
    border-radius: 3px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

#resultado {
    font-size: 16px;
    margin-top: 10px;
    font-weight: normal;
    background: rgba(0, 0, 0, 0.05);
    padding: 8px;
    border-radius: 4px;
}