:root {
  --teal: #0f766e;
  --teal-dark: #115e59;
  --bg: #f8fafc;
  --card: #ffffff;
  --ink: #0f172a;
  --muted: #64748b;
  --border: #e2e8f0;
  --danger: #b91c1c;
  --danger-bg: #fef2f2;
  --low: #fffbeb;
  --low-border: #f59e0b;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--ink);
}
.topbar {
  display: flex; align-items: center; justify-content: space-between;
  background: var(--teal); color: #fff; padding: 12px 16px;
  position: sticky; top: 0; z-index: 10;
}
.brand { color: #fff; text-decoration: none; font-weight: 700; font-size: 1.05rem; }
.demo-tag {
  font-size: .65rem; text-transform: uppercase; background: rgba(255,255,255,.2);
  padding: 2px 6px; border-radius: 6px; margin-left: 4px; vertical-align: middle;
}
.container { max-width: 820px; margin: 0 auto; padding: 16px; }
h1 { font-size: 1.4rem; margin: 8px 0 16px; }
h2 { font-size: 1.15rem; }
.hint { color: var(--muted); font-size: .9rem; }

/* Menu tiles */
.menu { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.tile {
  display: flex; flex-direction: column; gap: 4px;
  background: var(--card); border: 1px solid var(--border); border-radius: 14px;
  padding: 20px; text-decoration: none; color: var(--ink); min-height: 110px;
  box-shadow: 0 1px 2px rgba(0,0,0,.04);
}
.tile:hover { border-color: var(--teal); }
.tile-icon { font-size: 1.8rem; }
.tile-label { font-weight: 700; font-size: 1.1rem; }
.tile-sub { color: var(--muted); font-size: .85rem; }
.tile-disabled { opacity: .5; cursor: not-allowed; }

/* Buttons */
.btn {
  display: inline-block; border: 1px solid var(--border); background: #fff; color: var(--ink);
  border-radius: 10px; padding: 10px 16px; font-size: 1rem; cursor: pointer; text-decoration: none;
  margin: 6px 6px 6px 0;
}
.btn.primary { background: var(--teal); border-color: var(--teal); color: #fff; }
.btn.primary:hover { background: var(--teal-dark); }
.btn.ghost { background: transparent; }
.btn.big { font-size: 1.1rem; padding: 14px 22px; }
.camera-btn { white-space: nowrap; }

/* Scan field */
.scanfield { display: flex; gap: 8px; margin: 12px 0; flex-wrap: wrap; }
.scan-input {
  flex: 1 1 240px; font-size: 1.1rem; padding: 12px; border: 2px solid var(--teal);
  border-radius: 10px; font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}
.reader { margin: 10px 0; max-width: 360px; }

/* Tables */
.grid { width: 100%; border-collapse: collapse; margin: 12px 0; background: var(--card); }
.grid th, .grid td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--border); }
.grid th.num, .grid td.num { text-align: right; }
.mono { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }
.qty-edit { width: 72px; padding: 6px; text-align: right; }
.np-pid, .np-desc { width: 100%; padding: 8px; border: 1px solid var(--border); border-radius: 8px; }
.empty { color: var(--muted); text-align: center; }

/* Low stock highlight */
.low-stock { background: var(--low); }
.badge {
  background: var(--low-border); color: #fff; font-size: .65rem; text-transform: uppercase;
  padding: 1px 6px; border-radius: 6px; margin-left: 6px;
}

/* Messages */
.message { padding: 10px 12px; border-radius: 10px; margin: 10px 0; }
.message.error { background: var(--danger-bg); color: var(--danger); border: 1px solid #fecaca; }
.done { font-size: 1.1rem; }