// client.js (in your existing <script>)
let remaining = 12;
async function refreshRemaining() {
    try {
        const r = await fetch('/api/inventory'); const j = await r.json();
        remaining = j.remaining;
        document.querySelectorAll('[data-remaining] .remN').forEach(s => s.textContent = remaining);
        // Disable all three server buttons if none left:
        if (remaining <= 0) {
            document.querySelectorAll('[data-add="server1"],[data-add="server2"],[data-add="server3"]').forEach(btn => {
                btn.disabled = true; btn.textContent = 'Sold out';
            });
        }
    } catch { }
}
refreshRemaining();
setInterval(refreshRemaining, 30_000); // stay “24/7” up-to-date