/* Global reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Roboto', sans-serif;
}

/* Body background */
body {
    background: linear-gradient(145deg, #f7f7f7, #f1f1f1);
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

/* Container for the cash register */
.container {
    width: 100%;
    max-width: 700px;
    padding: 40px;
    background: #fff;
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

/* Cash Register Box */
.cash-register {
    background: linear-gradient(145deg, #d4af7f, #b38b4c);
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.cash-register .header {
    text-align: center;
    margin-bottom: 30px;
}

.cash-register h1 {
    color: #fff;
    font-size: 36px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

/* Input Fields */
.input-section {
    margin-bottom: 20px;
}

.input-section label {
    color: #fff;
    display: block;
    font-size: 14px;
    margin-bottom: 8px;
}

.input-section input {
    width: 100%;
    padding: 12px;
    border: 2px solid #b38b4c;
    border-radius: 8px;
    background-color: #f5f5f5;
    font-size: 16px;
    color: #333;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.input-section input:focus {
    outline: none;
    border-color: #ffd700;
    box-shadow: 0 4px 12px rgba(255, 215, 0, 0.3);
}

/* Result Section */
.result-section {
    text-align: center;
    margin-top: 20px;
}

#change-due {
    font-size: 20px;
    color: #444;
    font-weight: 500;
    margin-bottom: 20px;
}

#purchase-btn {
    background: #ff8c00;
    color: white;
    padding: 15px 25px;
    border: none;
    border-radius: 8px;
    font-size: 18px;
    cursor: pointer;
    transition: background-color 0.3s ease;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}

#purchase-btn:hover {
    background-color: #ff6e00;
}

#purchase-btn:focus {
    outline: none;
    box-shadow: 0 0 10px rgba(255, 140, 0, 0.5);
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 20px;
        max-width: 100%;
    }

    .cash-register {
        padding: 15px;
    }

    .cash-register h1 {
        font-size: 28px;
    }

    #change-due {
        font-size: 18px;
    }

    #purchase-btn {
        font-size: 16px;
    }
}

@media (max-width: 480px) {
    .cash-register h1 {
        font-size: 24px;
    }

    #change-due {
        font-size: 16px;
    }

    .input-section input {
        font-size: 14px;
    }

    #purchase-btn {
        font-size: 14px;
    }
}