body {
    font-family: Arial, sans-serif;
    background-color: #111;
    color: white;
    text-align: center;
    padding: 20px;
}

.container {
    max-width: 400px;
    margin: auto;
    background: #222;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0px 0px 15px rgba(255, 165, 0, 0.5);
}

h1 {
    font-size: 24px;
    color: #ffa500;
}

p {
    font-size: 14px;
    margin: 10px 0;
}

.calculator {
    margin-top: 20px;
}

input[type="range"] {
    width: 100%;
    margin: 10px 0;
    cursor: pointer;
}

.result {
    background: #333;
    padding: 10px;
    border-radius: 5px;
    box-shadow: inset 0px 0px 10px rgba(255, 165, 0, 0.3);
}

span {
    font-weight: bold;
    color: #ffa500;
}

.topup-btn {
    display: block;
    background: #fbaed2;
    color: white;
    padding: 10px;
    margin-top: 20px;
    border-radius: 5px;
    text-decoration: none;
    font-size: 16px;
    transition: all 0.3s ease-in-out;
}

.topup-btn:hover {
    background: #708090;
    transform: scale(1.05);
}

.btn-back {
    display: block;
    background: #fbaed2; /* Warna latar tombol */
    color: white; /* Warna teks */
    padding: 10px;
    margin-top: 10px;
    border-radius: 5px;
    text-decoration: none;
    text-align: center;
    font-size: 16px;
    transition: all 0.3s ease;
    cursor: pointer;
}

.btn-back:hover {
    background: #708090; /* Warna saat hover */
}