body {
    font-family: Arial, sans-serif;
    margin: 0;
    background: #f4f6f8;
    color: #222;
}

.topbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 24px;
    background: white;
    border-bottom: 1px solid #ddd;
}

.topbar h1 {
    margin: 0;
}

.topbar p {
    margin: 5px 0 0;
    color: #666;
}

button {
    padding: 11px 16px;
    font-size: 15px;
    cursor: pointer;
}

.pos-nav {
    display: flex;
    gap: 8px;
    padding: 12px 20px;
    background: #e9edf2;
    overflow-x: auto;
}

.nav-button {
    white-space: nowrap;
}

.nav-button.active {
    font-weight: bold;
}

.pos-layout {
    display: grid;
    grid-template-columns: 1.6fr 1fr;
    gap: 20px;
    padding: 20px;
}

.product-panel,
.cart-panel {
    background: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

.product-search-row {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

#product-search {
    flex: 1;
    padding: 12px;
    font-size: 16px;
}

#product-results,
#cart-items {
    min-height: 180px;
    padding: 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    background: #fafafa;
}

.cart-summary {
    margin-top: 20px;
}

.cart-summary p {
    display: flex;
    justify-content: space-between;
}

.cart-total {
    font-size: 20px;
}

#checkout-button {
    width: 100%;
    margin-top: 15px;
}

#checkout-button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

@media (max-width: 800px) {

    .topbar {
        align-items: flex-start;
        gap: 15px;
    }

    .pos-layout {
        grid-template-columns: 1fr;
    }

    .product-search-row {
        flex-direction: column;
    }

    #scan-button {
        width: 100%;
    }
}