body {
    margin: 0;
    min-height: 100vh;
    font-family: Arial, sans-serif;
    background: linear-gradient(135deg, #1e90ff, #4facfe);
    display: flex;
    justify-content: center;
    align-items: flex-start; /* supaya card mulai dari atas */
    padding: 20px; /* beri ruang di pinggir layar */
    box-sizing: border-box;
}

/* Card utama */
.card {
    background: #ffffff;
    width: 90%;         /* lebar 90% dari viewport */
    max-width: 800px;   /* maksimal lebar 800px */
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
    box-sizing: border-box;
    margin-top: 20px;   /* beri jarak atas */
}

/* Judul */
.card h2 {
    text-align: center;
    margin-bottom: 20px;
    color: #1e90ff;
}

/* Item data */
.item {
    background: #f2f7ff;
    border-left: 5px solid #1e90ff;
    padding: 10px 12px;
    margin-bottom: 10px;
    border-radius: 6px;
    font-size: 16px; /* ukuran font nyaman dibaca */
}

/* Tombol */
button {
    background: linear-gradient(135deg, #1e90ff, #4facfe);
    border: none;
    color: white;
    padding: 12px 30px;
    border-radius: 25px;
    cursor: pointer;
    font-size: 16px;
    transition: opacity 0.3s ease;
}

button:hover {
    opacity: 0.9;
}

/* Center form */
.center {
    text-align: center;
}

/* Input text */
input[type="text"] {
    width: 100%;
    padding: 10px;
    margin-top: 5px;
    border-radius: 5px;
    border: 1px solid #ccc;
    box-sizing: border-box;
    font-size: 16px;
}

/* Responsive adjustments untuk layar kecil */
@media (max-width: 480px) {
    body {
        padding: 10px;
        align-items: center; /* agar card di tengah secara vertikal */
    }
    .card {
        width: 100%;
        max-width: none;
        padding: 15px;
        margin-top: 10px;
    }
    .item {
        font-size: 14px;
        padding: 8px 10px;
    }
    button {
        padding: 10px 20px;
        font-size: 14px;
    }
    input[type="text"] {
        padding: 8px;
        font-size: 14px;
    }
}