:root {
  /* Colors */
  --primary: #4F46E5;
  --primary-hover: #4338CA;
  --secondary: #6B7280;
  --background: #F3F4F6;
  --surface: #FFFFFF;
  --text-main: #111827;
  --text-muted: #6B7280;
  --text-inverse: #FFFFFF;
  
  --success: #10B981;
  --warning: #F59E0B;
  --danger: #EF4444;
  --info: #3B82F6;

  /* Geometry & Shadows */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-glass: 0 8px 32px 0 rgba(31, 38, 135, 0.07);

  /* Transitions */
  --trans-fast: 0.15s ease-in-out;
  --trans-normal: 0.25s ease-in-out;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--background);
  color: var(--text-main);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  display: flex;
  height: 100vh;
  overflow: hidden;
}

/* Typography */
h1, h2, h3, h4, h5 { font-weight: 600; color: var(--text-main); }
h1 { font-size: 1.5rem; }
h2 { font-size: 1.25rem; }
h3 { font-size: 1.125rem; }
p { color: var(--text-muted); }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  transition: all var(--trans-fast);
  gap: 0.5rem;
}
.btn:disabled { opacity: 0.6; cursor: not-allowed; }
.btn-primary { background-color: var(--primary); color: var(--text-inverse); }
.btn-primary:hover { background-color: var(--primary-hover); transform: translateY(-1px); }
.btn-secondary { background-color: var(--surface); color: var(--text-main); border: 1px solid #D1D5DB; }
.btn-secondary:hover { background-color: #F9FAFB; }
.btn-danger { background-color: #FEE2E2; color: var(--danger); }
.btn-danger:hover { background-color: #FECACA; }
.btn-ghost { background-color: transparent; color: var(--text-muted); }
.btn-ghost:hover { background-color: #E5E7EB; color: var(--text-main); }

/* Inputs */
.input-control {
  width: 100%;
  padding: 0.625rem 0.875rem;
  font-size: 0.875rem;
  border: 1px solid #D1D5DB;
  border-radius: var(--radius-sm);
  background-color: var(--surface);
  transition: border-color var(--trans-fast), box-shadow var(--trans-fast);
}
.input-control:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.2);
}
.form-group {
  margin-bottom: 1rem;
}
.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.375rem;
  color: #374151;
}

/* Layout: Sidebar */
.sidebar {
  width: 260px;
  background-color: var(--surface);
  border-right: 1px solid #E5E7EB;
  display: flex;
  flex-direction: column;
  z-index: 10;
  transition: transform var(--trans-normal);
}
.sidebar-header {
  height: 64px;
  display: flex;
  align-items: center;
  padding: 0 1.5rem;
  border-bottom: 1px solid #E5E7EB;
}
.sidebar-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.sidebar-nav {
  padding: 1.5rem 1rem;
  flex: 1;
  overflow-y: auto;
}
.nav-item {
  display: flex;
  align-items: center;
  padding: 0.75rem 1rem;
  color: var(--text-muted);
  text-decoration: none;
  border-radius: var(--radius-sm);
  margin-bottom: 0.25rem;
  font-weight: 500;
  font-size: 0.875rem;
  transition: all var(--trans-fast);
  gap: 0.75rem;
}
.nav-item:hover {
  background-color: #F3F4F6;
  color: var(--text-main);
}
.nav-item.active {
  background-color: #EEF2FF;
  color: var(--primary);
}
.sidebar-footer {
  padding: 1rem;
  border-top: 1px solid #E5E7EB;
}
.user-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.user-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--primary);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 0.875rem;
}

/* Layout: Main */
.main-wrapper {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.topbar {
  height: 64px;
  background-color: var(--surface);
  border-bottom: 1px solid #E5E7EB;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  z-index: 5;
}
.content-area {
  flex: 1;
  overflow-y: auto;
  padding: 2rem;
  position: relative;
}

/* Cards & Dashboards */
.card {
  background: var(--surface);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  border: 1px solid #E5E7EB;
  margin-bottom: 1.5rem;
  overflow: hidden;
}
.card-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid #F3F4F6;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.card-body {
  padding: 1.5rem;
}
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.5rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; }

/* Stat Widgets */
.stat-widget {
  background: var(--surface);
  padding: 1.5rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  border: 1px solid #E5E7EB;
  display: flex;
  flex-direction: column;
  transition: transform var(--trans-fast);
}
.stat-widget:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.stat-title { color: var(--text-muted); font-size: 0.875rem; font-weight: 500; margin-bottom: 0.5rem; }
.stat-value { color: var(--text-main); font-size: 1.875rem; font-weight: 700; display: flex; align-items: baseline; gap: 0.5rem; }
.stat-trend { font-size: 0.875rem; font-weight: 500; }
.trend-up { color: var(--success); }
.trend-down { color: var(--danger); }

/* Tables */
.table-wrapper {
  overflow-x: auto;
  width: 100%;
}
.data-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}
.data-table th {
  background-color: #F9FAFB;
  padding: 0.75rem 1rem;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-bottom: 1px solid #E5E7EB;
}
.data-table td {
  padding: 1rem;
  font-size: 0.875rem;
  color: var(--text-main);
  border-bottom: 1px solid #E5E7EB;
  vertical-align: middle;
}
.data-table tbody tr:hover {
  background-color: #F9FAFB;
}

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.125rem 0.625rem;
  font-size: 0.75rem;
  font-weight: 500;
  border-radius: 9999px;
}
.badge-success { background-color: #D1FAE5; color: #065F46; }
.badge-warning { background-color: #FEF3C7; color: #92400E; }
.badge-danger { background-color: #FEE2E2; color: #991B1B; }
.badge-info { background-color: #DBEAFE; color: #1E40AF; }

/* Modals */
.modal-overlay {
  position: fixed;
  top: 0; left: 0; width: 100%; height: 100%;
  background-color: rgba(17, 24, 39, 0.5);
  backdrop-filter: blur(4px);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 50;
  opacity: 0;
  transition: opacity var(--trans-normal);
}
.modal-overlay.active {
  display: flex;
  opacity: 1;
}
.modal-container {
  background-color: var(--surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 600px;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  transform: scale(0.95) translateY(10px);
  transition: transform var(--trans-normal);
}
.modal-container.modal-wide {
  width: min(96vw, 1200px);
  max-width: 1200px;
}
.modal-overlay.active .modal-container {
  transform: scale(1) translateY(0);
}
.modal-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid #E5E7EB;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.modal-body {
  padding: 1.5rem;
  overflow-y: auto;
}
.modal-footer {
  padding: 1.25rem 1.5rem;
  border-top: 1px solid #E5E7EB;
  display: flex;
  justify-content: flex-end;
  gap: 0.75rem;
}
.close-btn { background: none; border: none; font-size: 1.25rem; cursor: pointer; color: var(--text-muted); }
.close-btn:hover { color: var(--text-main); }

/* Toasts */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 100;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.toast {
  background-color: var(--text-main);
  color: white;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-md);
  font-size: 0.875rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-width: 300px;
  opacity: 0;
  transform: translateY(20px);
  animation: toast-slide-in 0.3s forwards;
}
@keyframes toast-slide-in {
  to { opacity: 1; transform: translateY(0); }
}

/* Utilities */
.hidden { display: none !important; }
.flex { display: flex; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: 0.5rem; }
.gap-4 { gap: 1rem; }
.mt-4 { margin-top: 1rem; }
.mb-4 { margin-bottom: 1rem; }
.text-right { text-align: right; }