body {
    font-family: 'Segoe UI', Arial, sans-serif;
    background: #f7faff;
    color: #333;
    text-align: center;
    padding: 30px;
}

h1 {
    margin-bottom: 20px;
}

.card {
    display: none;
    margin: 0 auto 30px;
    max-width: 480px;
    border-radius: 18px;
    overflow: hidden;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
}

.card.active {
    display: table;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 10px;
    font-size: 14px;
    cursor: pointer;
    margin: 5px;
    transition: 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.toggle-btn {
    background: #2a4d69;
    color: #fff;
}

.toggle-btn:hover {
    background: #1c3449;
}

.copy-btn {
    background: #2ae98b;
    color: #000;
}

.copy-btn:hover {
    background: #1fa864;
    color: #fff;
}