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

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --danger: #dc2626;
  --success: #16a34a;
  --warning: #f59e0b;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-500: #6b7280;
  --gray-700: #374151;
  --gray-900: #111827;
  --radius: 8px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--gray-50);
  color: var(--gray-900);
  line-height: 1.5;
}

/* ---------- Login ---------- */
.login-container {
  max-width: 360px;
  margin: 120px auto;
  padding: 32px;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
  text-align: center;
}
.login-container h1 {
  font-size: 24px;
  margin-bottom: 4px;
}
.subtitle {
  color: var(--gray-500);
  margin-bottom: 24px;
}
.form-group {
  margin-bottom: 16px;
  text-align: left;
}
.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 4px;
  color: var(--gray-700);
}
.form-group input, .form-group select, .form-group textarea {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius);
  font-size: 14px;
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}
.error {
  color: var(--danger);
  font-size: 14px;
  margin-bottom: 12px;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 16px;
  border: none;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s;
}
.btn-primary {
  background: var(--primary);
  color: #fff;
}
.btn-primary:hover {
  background: var(--primary-dark);
}
.btn-success {
  background: var(--success);
  color: #fff;
}
.btn-danger {
  background: var(--danger);
  color: #fff;
}
.btn-outline {
  background: transparent;
  border: 1px solid var(--gray-300);
  color: var(--gray-700);
}
.btn-outline:hover {
  background: var(--gray-100);
}
.btn-sm {
  padding: 4px 12px;
  font-size: 13px;
}
.btn-block {
  width: 100%;
}

/* ---------- Navbar ---------- */
.navbar {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 24px;
  background: #fff;
  border-bottom: 1px solid var(--gray-200);
}
.nav-brand {
  font-size: 18px;
  font-weight: 700;
  margin-right: auto;
}
.nav-tabs {
  display: flex;
  gap: 4px;
}
.tab {
  padding: 6px 14px;
  background: none;
  border: none;
  border-radius: var(--radius);
  font-size: 14px;
  cursor: pointer;
  color: var(--gray-500);
}
.tab.active {
  background: var(--primary);
  color: #fff;
}

/* ---------- Container ---------- */
.container {
  max-width: 1100px;
  margin: 24px auto;
  padding: 0 24px;
}

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

/* ---------- Section Header ---------- */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}
.header-actions {
  display: flex;
  gap: 8px;
  align-items: center;
}
.header-actions select {
  padding: 6px 10px;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius);
  font-size: 13px;
}

/* ---------- Data Table ---------- */
.data-table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(0,0,0,0.08);
}
.data-table th {
  text-align: left;
  padding: 10px 14px;
  background: var(--gray-100);
  font-size: 13px;
  font-weight: 600;
  color: var(--gray-500);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}
.data-table td {
  padding: 10px 14px;
  border-top: 1px solid var(--gray-200);
  font-size: 14px;
}
.data-table tr:hover td {
  background: var(--gray-50);
}

/* ---------- Status Badges ---------- */
.badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
}
.badge-proposed { background: #fef3c7; color: #92400e; }
.badge-confirmed { background: #dcfce7; color: #166534; }
.badge-cancelled { background: #fee2e2; color: #991b1b; }

/* ---------- Modal ---------- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
}
.modal {
  background: #fff;
  border-radius: var(--radius);
  width: 90%;
  max-width: 500px;
  max-height: 80vh;
  overflow-y: auto;
  box-shadow: 0 10px 40px rgba(0,0,0,0.2);
}
.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--gray-200);
}
.modal-header h3 {
  font-size: 18px;
}
.modal-close {
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--gray-500);
}
.modal-body {
  padding: 20px;
}
.modal-body .form-group:last-of-type {
  margin-bottom: 20px;
}

/* ---------- Settings ---------- */
.settings-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}
.settings-card {
  background: #fff;
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.08);
}
.settings-card h3 {
  font-size: 16px;
  margin-bottom: 4px;
}
.settings-desc {
  color: var(--gray-500);
  font-size: 13px;
  margin-bottom: 16px;
}
.settings-actions {
  display: flex;
  gap: 8px;
}
.input-readonly {
  background: var(--gray-100) !important;
  color: var(--gray-500) !important;
  cursor: default;
}
.test-result {
  margin-top: 12px;
  padding: 8px 12px;
  border-radius: var(--radius);
  font-size: 13px;
}
.test-loading {
  background: var(--gray-100);
  color: var(--gray-700);
}
.test-success {
  background: #dcfce7;
  color: #166534;
}
.test-fail {
  background: #fee2e2;
  color: #991b1b;
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .navbar {
    flex-wrap: wrap;
  }
  .nav-tabs {
    order: 3;
    width: 100%;
    overflow-x: auto;
  }
  .data-table {
    font-size: 13px;
  }
  .data-table th, .data-table td {
    padding: 8px 10px;
  }
  .settings-grid {
    grid-template-columns: 1fr;
  }
}