:root {
  --primary: #ea580c;
  --primary-light: #fb923c;
  --primary-dark: #c2410c;
  --bg: #ffffff;
  --bg-card: #f9fafb;
  --bg-input: #ffffff;
  --text: #111827;
  --text-secondary: #6b7280;
  --border: #e5e7eb;
  --success: #16a34a;
  --warning: #eab308;
  --danger: #dc2626;
  --danger-dark: #991b1b;
  --aging-current: #16a34a;
  --aging-30: #eab308;
  --aging-60: #f97316;
  --aging-90: #dc2626;
  --aging-90plus: #991b1b;
  --shadow: 0 1px 3px rgba(0,0,0,0.1);
  --radius: 8px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111827;
    --bg-card: #1f2937;
    --bg-input: #374151;
    --text: #f3f4f6;
    --text-secondary: #9ca3af;
    --border: #374151;
    --shadow: 0 1px 3px rgba(0,0,0,0.3);
  }
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  padding-bottom: 72px;
  -webkit-font-smoothing: antialiased;
}

#app {
  max-width: 640px;
  margin: 0 auto;
  padding: 16px;
}

#bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  justify-content: space-around;
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  padding: 6px 0 env(safe-area-inset-bottom, 6px);
  z-index: 100;
}

.nav-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 10px;
  padding: 4px 8px;
  cursor: pointer;
  transition: color 0.2s;
}

.nav-btn.active { color: var(--primary); }
.nav-btn svg { width: 22px; height: 22px; }

.screen-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  padding: 8px 0;
}

.screen-header h1 {
  font-size: 22px;
  font-weight: 700;
}

.screen-header .subtitle {
  font-size: 13px;
  color: var(--text-secondary);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 18px;
  border: none;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.2s;
}

.btn:active { opacity: 0.8; }
.btn-primary { background: var(--primary); color: #fff; }
.btn-secondary { background: var(--bg-card); color: var(--text); border: 1px solid var(--border); }
.btn-danger { background: var(--danger); color: #fff; }
.btn-success { background: var(--success); color: #fff; }
.btn-sm { padding: 6px 12px; font-size: 12px; }
.btn-block { width: 100%; }
.btn-icon { padding: 8px; border-radius: 50%; background: none; border: none; color: var(--text-secondary); cursor: pointer; }

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  margin-bottom: 10px;
  box-shadow: var(--shadow);
}

.card-clickable { cursor: pointer; transition: transform 0.15s; }
.card-clickable:active { transform: scale(0.98); }

.stat-big {
  font-size: 32px;
  font-weight: 800;
  color: var(--primary);
}

.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 12px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
}

.badge-draft { background: #e5e7eb; color: #374151; }
.badge-sent { background: #dbeafe; color: #1d4ed8; }
.badge-overdue { background: #fee2e2; color: #dc2626; }
.badge-paid { background: #dcfce7; color: #16a34a; }
.badge-partial { background: #fef3c7; color: #d97706; }
.badge-void { background: #f3f4f6; color: #6b7280; }

.form-group {
  margin-bottom: 14px;
}

.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 4px;
  color: var(--text-secondary);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 15px;
  background: var(--bg-input);
  color: var(--text);
  font-family: inherit;
}

.form-group textarea { resize: vertical; min-height: 60px; }
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 2px rgba(234,88,12,0.2);
}

.form-row {
  display: flex;
  gap: 10px;
}

.form-row .form-group { flex: 1; }

.list-empty {
  text-align: center;
  padding: 40px 20px;
  color: var(--text-secondary);
  font-size: 14px;
}

.filter-tabs {
  display: flex;
  gap: 6px;
  margin-bottom: 14px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.filter-tab {
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: none;
  color: var(--text-secondary);
  font-size: 13px;
  white-space: nowrap;
  cursor: pointer;
}

.filter-tab.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.line-item-row {
  display: grid;
  grid-template-columns: 1fr 60px 80px 80px 36px;
  gap: 6px;
  align-items: end;
  margin-bottom: 8px;
}

.line-item-row input {
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 13px;
  background: var(--bg-input);
  color: var(--text);
}

.line-item-row .remove-btn {
  background: none;
  border: none;
  color: var(--danger);
  cursor: pointer;
  font-size: 18px;
  padding: 4px;
}

.line-item-header {
  display: grid;
  grid-template-columns: 1fr 60px 80px 80px 36px;
  gap: 6px;
  font-size: 11px;
  color: var(--text-secondary);
  font-weight: 600;
  margin-bottom: 4px;
  padding: 0 2px;
}

.totals-section {
  border-top: 1px solid var(--border);
  padding-top: 12px;
  margin-top: 12px;
}

.total-row {
  display: flex;
  justify-content: space-between;
  padding: 4px 0;
  font-size: 14px;
}

.total-row.total-final {
  font-weight: 700;
  font-size: 18px;
  border-top: 2px solid var(--border);
  padding-top: 8px;
  margin-top: 4px;
}

.aging-bar-container {
  margin: 16px 0;
}

.reliability-dot {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  margin-right: 6px;
}

.dot-green { background: var(--success); }
.dot-yellow { background: var(--warning); }
.dot-red { background: var(--danger); }

.reminder-card {
  border-left: 4px solid var(--primary);
  position: relative;
}

.reminder-ready {
  border-left-color: var(--danger);
}

.reminder-ready::before {
  content: '';
  position: absolute;
  top: 14px;
  right: 14px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--danger);
  animation: pulse 1.5s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.3; }
}

.action-bar {
  display: flex;
  gap: 8px;
  margin-top: 10px;
  flex-wrap: wrap;
}

.status-flow {
  display: flex;
  gap: 4px;
  align-items: center;
  margin: 12px 0;
  font-size: 12px;
}

.status-step {
  padding: 4px 10px;
  border-radius: 12px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
}

.status-step.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.status-arrow { color: var(--text-secondary); }

.invoice-print {
  background: #fff;
  color: #111;
  padding: 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.invoice-print-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 24px;
}

.invoice-print table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
}

.invoice-print th,
.invoice-print td {
  padding: 8px;
  text-align: left;
  border-bottom: 1px solid #e5e7eb;
  font-size: 13px;
}

.invoice-print th { font-weight: 600; color: #6b7280; }
.invoice-print td:last-child,
.invoice-print th:last-child { text-align: right; }

.late-fee-text { color: var(--danger); }

.section-title {
  font-size: 15px;
  font-weight: 700;
  margin: 16px 0 8px;
}

.back-btn {
  background: none;
  border: none;
  color: var(--primary);
  font-size: 14px;
  cursor: pointer;
  padding: 4px 0;
  display: flex;
  align-items: center;
  gap: 4px;
}

.toast {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%);
  background: #333;
  color: #fff;
  padding: 10px 20px;
  border-radius: 20px;
  font-size: 13px;
  z-index: 200;
  opacity: 0;
  transition: opacity 0.3s;
  pointer-events: none;
}

.toast.show { opacity: 1; }

.chart-container { margin: 16px 0; }

.payment-history-item {
  display: flex;
  justify-content: space-between;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
}

.template-editor textarea {
  width: 100%;
  min-height: 80px;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 13px;
  font-family: inherit;
  background: var(--bg-input);
  color: var(--text);
  resize: vertical;
}

.settings-section {
  margin-bottom: 24px;
}

.settings-section h3 {
  font-size: 15px;
  margin-bottom: 12px;
  color: var(--primary);
}

@media (min-width: 480px) {
  #app { padding: 20px; }
  .line-item-row { grid-template-columns: 1fr 70px 90px 90px 36px; }
}

@media print {
  #bottom-nav, .action-bar, .back-btn, .btn { display: none !important; }
  body { padding: 0; }
  #app { max-width: none; padding: 0; }
}