:root {
  --bg: #f5f6fa;
  --surface: #ffffff;
  --surface-2: #fafbfd;
  --border: #e3e6ec;
  --text: #1a1d24;
  --text-muted: #6b7280;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --danger: #dc2626;
  --success: #16a34a;
  --warning: #f59e0b;
  --info: #0ea5e9;
  --grey: #9ca3af;
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --radius: 8px;
}

[data-theme="dark"] {
  --bg: #0f1115;
  --surface: #1a1d24;
  --surface-2: #22262e;
  --border: #2d323b;
  --text: #e6e8ed;
  --text-muted: #9097a3;
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --shadow: 0 1px 3px rgba(0,0,0,0.4);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
}

body {
  display: flex;
  min-height: 100vh;
}

/* === SIDEBAR === */
.sidebar {
  width: 240px;
  background: var(--surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  padding: 24px 16px;
  position: sticky;
  top: 0;
  height: 100vh;
}
.brand h2 { margin: 0 0 4px; font-size: 18px; }
.brand .muted { font-size: 12px; }
.muted { color: var(--text-muted); }
.sidebar nav {
  margin-top: 32px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  flex: 1;
}
.nav-link {
  padding: 10px 12px;
  border-radius: var(--radius);
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  transition: background .15s;
}
.nav-link:hover { background: var(--surface-2); }
.nav-link.active { background: var(--primary); color: #fff; }
.sidebar-footer {
  display: flex;
  flex-direction: column;
  gap: 8px;
  border-top: 1px solid var(--border);
  padding-top: 16px;
}

/* === MAIN === */
main {
  flex: 1;
  padding: 32px;
  overflow-x: auto;
}

.page-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 12px;
}
.page-header h1 { margin: 0; font-size: 24px; }
.actions { display: flex; gap: 8px; flex-wrap: wrap; }

/* === BUTTONS === */
button, .btn {
  font: inherit;
  padding: 8px 16px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  transition: all .15s;
}
button:hover, .btn:hover { background: var(--surface-2); }
.primary-btn {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}
.primary-btn:hover { background: var(--primary-hover); border-color: var(--primary-hover); }
.danger-btn { color: var(--danger); border-color: var(--danger); background: transparent; }
.danger-btn:hover { background: var(--danger); color: #fff; }
.ghost-btn {
  background: transparent;
  border: 1px solid var(--border);
  text-align: left;
}
.icon-btn {
  padding: 4px 8px;
  font-size: 13px;
}

/* === FILTERS === */
.filters {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  background: var(--surface);
  padding: 12px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  margin-bottom: 16px;
}
.filters select, .filters input {
  padding: 6px 10px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text);
}

/* === CARDS / GRID === */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
}
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}
.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
}
.stat-card .label {
  font-size: 12px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: .5px;
}
.stat-card .value {
  font-size: 22px;
  font-weight: 600;
  margin-top: 6px;
}
.stat-card.positive .value { color: var(--success); }
.stat-card.negative .value { color: var(--danger); }

/* === TABLES === */
.table-wrap {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: auto;
}
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}
th, td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}
th {
  background: var(--surface-2);
  font-weight: 600;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: .3px;
  color: var(--text-muted);
}
tbody tr:hover { background: var(--surface-2); }
tfoot td {
  font-weight: 600;
  background: var(--surface-2);
  border-top: 2px solid var(--border);
}
.num { text-align: right; font-variant-numeric: tabular-nums; }

/* === BADGES === */
.badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .3px;
}
.badge-betaald { background: rgba(22,163,74,.15); color: var(--success); }
.badge-verzonden { background: rgba(37,99,235,.15); color: var(--primary); }
.badge-wacht { background: rgba(245,158,11,.15); color: var(--warning); }
.badge-concept { background: rgba(156,163,175,.2); color: var(--grey); }
.badge-tebetalen { background: rgba(245,158,11,.15); color: var(--warning); }
.badge-verwacht { background: rgba(14,165,233,.15); color: var(--info); }

/* === MODAL === */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 16px;
}
.modal {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 24px;
  max-width: 540px;
  width: 100%;
  max-height: 90vh;
  overflow: auto;
  box-shadow: 0 20px 50px rgba(0,0,0,.3);
}
.modal h2 { margin-top: 0; }
.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  margin-top: 20px;
}

/* === FORMS === */
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.form-grid label.full { grid-column: 1 / -1; }
label {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 13px;
  color: var(--text-muted);
}
input, select, textarea {
  font: inherit;
  padding: 8px 10px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text);
}
input:focus, select:focus { outline: 2px solid var(--primary); outline-offset: -1px; }

/* === LOGIN === */
.login-body {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: linear-gradient(135deg, #2563eb 0%, #1e40af 100%);
}
.login-card {
  background: #fff;
  padding: 40px 32px;
  border-radius: 12px;
  width: 100%;
  max-width: 380px;
  box-shadow: 0 20px 60px rgba(0,0,0,.25);
  display: flex;
  flex-direction: column;
  gap: 14px;
  color: #1a1d24;
}
.login-card h1 { margin: 0; font-size: 22px; }
.login-card button {
  background: #2563eb;
  color: #fff;
  border: none;
  padding: 12px;
  font-weight: 600;
  margin-top: 6px;
}
.login-card .error { color: #dc2626; min-height: 18px; font-size: 13px; }

/* === MOBILE === */
@media (max-width: 768px) {
  body { flex-direction: column; }
  .sidebar {
    width: 100%;
    height: auto;
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
    padding: 12px;
  }
  .sidebar nav { flex-direction: row; flex-wrap: wrap; margin-top: 12px; }
  .sidebar-footer { flex-direction: row; }
  main { padding: 16px; }
  .form-grid { grid-template-columns: 1fr; }
}

.empty {
  text-align: center;
  padding: 40px;
  color: var(--text-muted);
}

.quarter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}
.quarter-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
}
.quarter-card h3 { margin: 0 0 10px; }
.quarter-card .row {
  display: flex;
  justify-content: space-between;
  padding: 4px 0;
  font-size: 13px;
}
.quarter-card .row.total {
  border-top: 1px solid var(--border);
  margin-top: 6px;
  padding-top: 8px;
  font-weight: 600;
}