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

:root {
  --bg: #0f1117;
  --surface: #1a1d27;
  --surface-hover: #222633;
  --border: #2a2e3d;
  --text: #e1e4ed;
  --text-muted: #8b90a0;
  --primary: #6c8aff;
  --primary-hover: #5a78f0;
  --success: #4ade80;
  --warning: #fbbf24;
  --danger: #f87171;
  --info: #60a5fa;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}

header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  gap: 2rem;
}

header h1 {
  font-size: 1.25rem;
  font-weight: 600;
  white-space: nowrap;
}

nav { display: flex; gap: 0.25rem; }

.tab-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  padding: 0.5rem 1rem;
  cursor: pointer;
  border-radius: 6px;
  font-size: 0.875rem;
  transition: all 0.15s;
}
.tab-btn:hover { color: var(--text); background: var(--surface-hover); }
.tab-btn.active { color: var(--primary); background: rgba(108,138,255,0.1); }

main { padding: 1.5rem 2rem; max-width: 1400px; margin: 0 auto; }

.tab-content { display: none; }
.tab-content.active { display: block; }

/* Summary cards */
.summary-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem;
}

.card-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
}

.card-value {
  font-size: 1.5rem;
  font-weight: 700;
}

.card-value.expense { color: var(--danger); }
.card-value.income { color: var(--success); }
.card-value.outstanding { color: var(--warning); }

/* Charts */
.charts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: 1.5rem;
}

.chart-container {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem;
}

.chart-container h3 {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

/* Toolbar */
.toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
  gap: 1rem;
  flex-wrap: wrap;
}

.filters { display: flex; gap: 0.5rem; align-items: center; flex-wrap: wrap; }

select, input[type="date"], input[type="text"], input[type="number"], textarea {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  font-size: 0.875rem;
}

select:focus, input:focus, textarea:focus {
  outline: none;
  border-color: var(--primary);
}

.btn {
  padding: 0.5rem 1rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.875rem;
  background: var(--surface);
  color: var(--text);
  transition: all 0.15s;
}
.btn:hover { background: var(--surface-hover); }
.btn-sm { padding: 0.375rem 0.75rem; font-size: 0.8rem; }
.btn-primary { background: var(--primary); color: #fff; border-color: var(--primary); }
.btn-primary:hover { background: var(--primary-hover); }
.btn-danger { color: var(--danger); }
.btn-danger:hover { background: rgba(248,113,113,0.1); }

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

thead { background: var(--surface-hover); }

th {
  padding: 0.75rem 1rem;
  text-align: left;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  font-weight: 600;
}

td {
  padding: 0.75rem 1rem;
  border-top: 1px solid var(--border);
  font-size: 0.875rem;
}

tr:hover td { background: var(--surface-hover); }

.amount { font-family: 'SF Mono', 'Fira Code', monospace; font-weight: 600; }
.amount.negative { color: var(--danger); }
.amount.positive { color: var(--success); }

.status-badge {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: capitalize;
}

.status-draft { background: rgba(139,144,160,0.15); color: var(--text-muted); }
.status-sent { background: rgba(96,165,250,0.15); color: var(--info); }
.status-paid { background: rgba(74,222,128,0.15); color: var(--success); }
.status-overdue { background: rgba(251,191,36,0.15); color: var(--warning); }
.status-cancelled { background: rgba(248,113,113,0.15); color: var(--danger); }

.category-badge {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border-radius: 12px;
  font-size: 0.75rem;
  background: rgba(108,138,255,0.1);
  color: var(--primary);
}

/* Pagination */
.pagination {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 1rem;
}

.pagination button {
  padding: 0.375rem 0.75rem;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.8rem;
}
.pagination button:hover { background: var(--surface-hover); }
.pagination button:disabled { opacity: 0.4; cursor: default; }

/* Modal */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  z-index: 1000;
  justify-content: center;
  align-items: flex-start;
  padding-top: 5vh;
}
.modal-overlay.active { display: flex; }

.modal {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  width: 90%;
  max-width: 600px;
  max-height: 85vh;
  overflow-y: auto;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.25rem;
  border-bottom: 1px solid var(--border);
}

.modal-header h2 { font-size: 1.1rem; }

.modal-close {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  cursor: pointer;
  line-height: 1;
}
.modal-close:hover { color: var(--text); }

.modal-body { padding: 1.25rem; }

/* Form styles inside modal */
.form-group { margin-bottom: 1rem; }
.form-group label {
  display: block;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
}
.form-group input, .form-group select, .form-group textarea {
  width: 100%;
}
.form-group textarea { min-height: 80px; resize: vertical; }

.form-row { display: flex; gap: 1rem; }
.form-row .form-group { flex: 1; }

.form-actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

/* Line items in invoice form */
.line-items-section { margin-top: 1rem; }
.line-items-section h4 {
  font-size: 0.875rem;
  margin-bottom: 0.5rem;
  color: var(--text-muted);
}

.line-item-row {
  display: flex;
  gap: 0.5rem;
  align-items: flex-end;
  margin-bottom: 0.5rem;
}

.line-item-row input { font-size: 0.8rem; padding: 0.4rem; }
.line-item-row .li-desc { flex: 3; }
.line-item-row .li-qty { flex: 1; min-width: 60px; }
.line-item-row .li-price { flex: 1; min-width: 80px; }

.line-item-remove {
  background: none;
  border: none;
  color: var(--danger);
  cursor: pointer;
  font-size: 1.2rem;
  padding: 0.4rem;
}

#add-line-item-btn {
  font-size: 0.8rem;
  margin-top: 0.25rem;
}

.empty-state {
  text-align: center;
  padding: 3rem;
  color: var(--text-muted);
}

@media (max-width: 768px) {
  header { flex-direction: column; align-items: flex-start; gap: 0.75rem; }
  main { padding: 1rem; }
  .charts-grid { grid-template-columns: 1fr; }
  .form-row { flex-direction: column; gap: 0; }
}