#battery-calculator {
    max-width: 600px;
    margin: 0 auto;
    padding: 30px;
    background: #4ecc70;
    border-radius: 15px;
    font-family: Arial, sans-serif;
    color: white;
}

#battery-calculator h2 {
    color: white;
}

#battery-calculator input[type="range"] {
    width: 100%;
    margin: 10px 0;
    border: 1px solid white;
    border-radius: 15px;
    padding: 5px;
    background: transparent;
    color: white;
}

#battery-calculator button {
    background: white;
    color: #4ecc70;
    border: none;
    border-radius: 25px;
    padding: 10px;
    cursor: pointer;
    width: 100%;
    margin-top: 15px;
}

#battery-calculator button:hover {
    background: #3cae5e;
    color: white;
}