:root {
  --bg: #f4f6f9;
  --card-bg: #ffffff;
  --border: #e2e5eb;
  --text: #1f2430;
  --text-muted: #6b7280;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --green: #16a34a;
  --green-bg: #dcfce7;
  --red: #dc2626;
  --red-bg: #fee2e2;
  --radius: 10px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

/* ---------- Login page ---------- */
.login-wrap {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
}

.login-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  width: 100%;
  max-width: 360px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}

.login-card h1 {
  font-size: 20px;
  margin: 0 0 4px;
}

.login-card p.sub {
  color: var(--text-muted);
  font-size: 13px;
  margin: 0 0 24px;
}

.field {
  margin-bottom: 16px;
}

.field label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 6px;
}

.field input, .field select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  background: #fff;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 16px;
  border-radius: 8px;
  border: none;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
}

.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-block { width: 100%; }
.btn-secondary { background: #eef0f4; color: var(--text); }
.btn-secondary:hover { background: #e2e5eb; }
.btn-danger { background: var(--red-bg); color: var(--red); }
.btn-danger:hover { background: #fecaca; }

.error-msg {
  background: var(--red-bg);
  color: var(--red);
  font-size: 13px;
  padding: 8px 12px;
  border-radius: 8px;
  margin-bottom: 16px;
  display: none;
}
.error-msg.show { display: block; }

/* ---------- Dashboard layout ---------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 24px;
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.topbar h1 {
  font-size: 17px;
  margin: 0;
}

.topbar .user-info {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 13px;
  color: var(--text-muted);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 14px;
  margin-bottom: 20px;
}

.summary-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
}

.summary-card .label {
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.summary-card .value {
  font-size: 22px;
  font-weight: 700;
}

.summary-card.green .value { color: var(--green); }
.summary-card.red .value { color: var(--red); }

.toolbar {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 16px;
  align-items: center;
}

.toolbar input[type="text"] {
  flex: 1;
  min-width: 200px;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
}

.toolbar select {
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  background: #fff;
}

.table-wrap {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  min-width: 720px;
}

thead th {
  text-align: left;
  padding: 12px 14px;
  border-bottom: 1px solid var(--border);
  color: var(--text-muted);
  font-weight: 600;
  white-space: nowrap;
}

tbody td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}

tbody tr:last-child td { border-bottom: none; }
tbody tr:hover { background: #fafbfc; }

.badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  user-select: none;
}

.badge.paid { background: var(--green-bg); color: var(--green); }
.badge.unpaid { background: var(--red-bg); color: var(--red); }

.row-actions {
  display: flex;
  gap: 8px;
}

.icon-btn {
  border: none;
  background: none;
  cursor: pointer;
  font-size: 13px;
  color: var(--text-muted);
  padding: 4px 6px;
  border-radius: 6px;
}
.icon-btn:hover { background: #eef0f4; color: var(--text); }

.empty-state {
  text-align: center;
  padding: 48px 16px;
  color: var(--text-muted);
}

.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-top: 16px;
  font-size: 13px;
  color: var(--text-muted);
}

/* ---------- Modal ---------- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 18, 25, 0.45);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 16px;
  z-index: 100;
}
.modal-overlay.show { display: flex; }

.modal {
  background: var(--card-bg);
  border-radius: var(--radius);
  width: 100%;
  max-width: 460px;
  padding: 24px;
  max-height: 90vh;
  overflow-y: auto;
}

.modal h2 {
  font-size: 17px;
  margin: 0 0 18px;
}

.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 20px;
}

.checkbox-row {
  display: flex;
  align-items: center;
  gap: 8px;
}
.checkbox-row input { width: auto; }

@media (max-width: 600px) {
  .container { padding: 14px; }
  .topbar { padding: 12px 14px; }
}