:root {
  --bg: #f8fafc;
  --card: #ffffff;
  --text: #0f172a;
  --muted: #64748b;
  --border: #e2e8f0;
  --input: #ffffff;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --success: #16a34a;
  --warning: #f59e0b;
  --danger: #dc2626;
  --shadow: 0 4px 14px rgba(15, 23, 42, 0.06);
}

body.dark {
  --bg: #0f172a;
  --card: #111827;
  --text: #f8fafc;
  --muted: #94a3b8;
  --border: #1f2937;
  --input: #0b1220;
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --success: #22c55e;
  --warning: #fbbf24;
  --danger: #ef4444;
  --shadow: 0 6px 20px rgba(0, 0, 0, 0.22);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
}

body {
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  transition: background 0.2s ease, color 0.2s ease;
}

.container {
  max-width: 980px;
  margin: 0 auto;
  padding: 20px;
}

.app {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: var(--shadow);
  padding: 20px;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 18px;
}

.topbar h1 {
  font-size: 1.35rem;
  margin-bottom: 4px;
}

.topbar p {
  color: var(--muted);
  font-size: 0.92rem;
}

.theme-btn {
  border: 1px solid var(--border);
  background: var(--input);
  color: var(--text);
  border-radius: 10px;
  padding: 8px 12px;
  cursor: pointer;
}

.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: 16px;
}

.stat {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
  background: var(--input);
}

.stat span {
  display: block;
  color: var(--muted);
  font-size: 0.85rem;
  margin-bottom: 6px;
}

.stat strong {
  font-size: 1.35rem;
}

.controls {
  margin-bottom: 14px;
}

.form-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1.2fr auto;
  gap: 10px;
  margin-bottom: 18px;
}

input,
button {
  font-size: 0.95rem;
  border-radius: 10px;
  padding: 11px 12px;
}

input {
  border: 1px solid var(--border);
  background: var(--input);
  color: var(--text);
  outline: none;
}

input::placeholder {
  color: var(--muted);
}

#addBtn {
  border: none;
  background: var(--primary);
  color: white;
  cursor: pointer;
}

#addBtn:hover {
  background: var(--primary-hover);
}

.table-wrap {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 700px;
}

th,
td {
  text-align: left;
  padding: 12px 10px;
  border-bottom: 1px solid var(--border);
}

th {
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 600;
}

.badge {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 600;
  padding: 4px 8px;
  border-radius: 999px;
}

.in-stock {
  background: rgba(34, 197, 94, 0.12);
  color: var(--success);
}

.low-stock {
  background: rgba(245, 158, 11, 0.14);
  color: var(--warning);
}

.actions {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.action-btn {
  border: none;
  border-radius: 8px;
  padding: 6px 9px;
  color: white;
  cursor: pointer;
  font-size: 0.82rem;
}

.plus-btn {
  background: var(--success);
}

.minus-btn {
  background: var(--warning);
  color: #111827;
}

.delete-btn {
  background: var(--danger);
}

.empty-state {
  text-align: center;
  color: var(--muted);
  padding: 22px 0;
}

.low-stock-row td {
  background: rgba(245, 158, 11, 0.05);
}

@media (max-width: 820px) {
  .form-grid {
    grid-template-columns: 1fr 1fr;
  }

  #addBtn {
    grid-column: span 2;
  }
}

@media (max-width: 640px) {
  .container {
    padding: 12px;
  }

  .app {
    padding: 16px;
  }

  .topbar {
    flex-direction: column;
    align-items: stretch;
  }

  .stats {
    grid-template-columns: 1fr;
  }

  .form-grid {
    grid-template-columns: 1fr;
  }

  #addBtn {
    grid-column: span 1;
  }

  .topbar h1 {
    font-size: 1.15rem;
  }
}