:root {
  --primary-color: #2563eb;
  --bg-color: #f8fafc;
  --card-bg: #ffffff;
  --text-color: #0f172a;
  --border-color: #e2e8f0;
  --danger-color: #ef4444;
  --success-color: #22c55e;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  padding-bottom: 60px;
}

.hidden { display: none !important; }
.bg-gray { background-color: var(--bg-color); }

/* Layout & Cards */
.container { padding: 16px; max-width: 600px; margin: 0 auto; }
.card {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 16px;
  border: 1px solid var(--border-color);
  box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

/* Typography & Inputs */
h1, h2, h3 { margin-top: 0; color: #1e293b; }
label { display: block; font-size: 0.875rem; font-weight: 600; margin-bottom: 4px; }
input, select, textarea, button {
  width: 100%;
  padding: 12px;
  margin-bottom: 12px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  box-sizing: border-box;
  font-size: 1rem;
}

button {
  background-color: var(--primary-color);
  color: white;
  border: none;
  font-weight: 600;
  cursor: pointer;
}

button.btn-success { background-color: var(--success-color); }
button.btn-danger { background-color: var(--danger-color); }
button:disabled { opacity: 0.6; cursor: not-allowed; }

/* Navigation Tabs */
.nav-tabs {
  display: flex;
  background: #ffffff;
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 10;
}

.tab-btn {
  flex: 1;
  padding: 12px;
  border: none;
  background: transparent;
  border-bottom: 2px solid transparent;
  border-radius: 0;
  color: #64748b;
}

.tab-btn.active {
  border-bottom-color: var(--primary-color);
  color: var(--primary-color);
  font-weight: bold;
}

/* Step Bar on Customer Tracking */
.step-bar { display: flex; gap: 8px; overflow-x: auto; padding: 8px 0; }
.step {
  padding: 6px 12px;
  background: #e2e8f0;
  border-radius: 16px;
  font-size: 0.85rem;
  white-space: nowrap;
}
.step.completed { background: #bbf7d0; color: #166534; font-weight: 600; }