:root {
  --color-primary: #3B82F6;
  --color-primary-dark: #2563EB;
  --color-primary-light: #60A5FA;
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-danger: #EF4444;
  --color-info: #06B6D4;
  
  --color-white: #FFFFFF;
  --color-gray-50: #F9FAFB;
  --color-gray-100: #F3F4F6;
  --color-gray-200: #E5E7EB;
  --color-gray-300: #D1D5DB;
  --color-gray-400: #9CA3AF;
  --color-gray-500: #6B7280;
  --color-gray-600: #4B5563;
  --color-gray-700: #374151;
  --color-gray-800: #1F2937;
  --color-gray-900: #111827;
  
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;
  
  --text-xs: 12px;
  --text-sm: 14px;
  --text-base: 16px;
  --text-lg: 20px;
  --text-xl: 24px;
  --text-2xl: 32px;
  --text-3xl: 48px;
  
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  
  --radius-sm: 8px;
  --radius-md: 10px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 20px;
  
  --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-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  
  --transition-fast: 0.15s ease;
  --transition-normal: 0.2s ease;
  --transition-slow: 0.3s ease;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--color-gray-50);
  color: var(--color-gray-800);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  text-decoration: none;
  color: inherit;
}

button {
  font-family: inherit;
}

input, textarea, select {
  font-family: inherit;
}

.app-shell {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  width: 260px;
  background: var(--color-gray-900);
  color: var(--color-white);
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  position: fixed;
  left: 0;
  top: 0;
  height: 100vh;
  overflow-y: auto;
}

.sidebar::-webkit-scrollbar {
  width: 6px;
}

.sidebar::-webkit-scrollbar-track {
  background: transparent;
}

.sidebar::-webkit-scrollbar-thumb {
  background: var(--color-gray-700);
  border-radius: 3px;
}

.sidebar h2 {
  margin: 0 0 var(--space-md);
  font-size: var(--text-lg);
  font-weight: 700;
  letter-spacing: -0.5px;
}

.nav {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  color: var(--color-gray-300);
  font-size: var(--text-sm);
  font-weight: 500;
  transition: all var(--transition-normal);
  cursor: pointer;
}

.nav:hover {
  background: rgba(255, 255, 255, 0.05);
  color: var(--color-white);
}

.nav.active {
  background: rgba(59, 130, 246, 0.15);
  color: var(--color-primary-light);
}

.nav svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

.main {
  flex: 1;
  margin-left: 260px;
  padding: var(--space-xl);
  min-height: 100vh;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-xl);
}

.topbar h1 {
  margin: 0;
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-gray-900);
}

.topbar-actions {
  display: flex;
  gap: var(--space-sm);
}

.card {
  background: var(--color-white);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-gray-100);
  margin-bottom: var(--space-lg);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-lg);
}

.card-title {
  margin: 0;
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-gray-900);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-md);
  overflow: hidden;
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.grid-full {
  grid-template-columns: 1fr;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.form-group label {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-gray-700);
}

.form-group label.checkbox-label {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  cursor: pointer;
}

.form-group label.checkbox-label input {
  width: auto;
  margin: 0;
}

input, select, textarea {
  width: 100%;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  background: var(--color-white);
  color: var(--color-gray-900);
  transition: all var(--transition-fast);
}

input:focus, select:focus, textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

input::placeholder, textarea::placeholder {
  color: var(--color-gray-400);
}

textarea {
  min-height: 100px;
  resize: vertical;
}

input[type="checkbox"], input[type="radio"] {
  width: auto;
  cursor: pointer;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-lg);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: all var(--transition-fast);
}

.btn svg {
  width: 16px;
  height: 16px;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  color: var(--color-white);
  box-shadow: 0 4px 14px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(59, 130, 246, 0.4);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: var(--color-gray-100);
  color: var(--color-gray-700);
}

.btn-secondary:hover {
  background: var(--color-gray-200);
}

.btn-success {
  background: var(--color-success);
  color: var(--color-white);
}

.btn-success:hover {
  background: #059669;
}

.btn-danger {
  background: var(--color-danger);
  color: var(--color-white);
}

.btn-danger:hover {
  background: #DC2626;
}

.btn-warning {
  background: var(--color-warning);
  color: var(--color-white);
}

.btn-warning:hover {
  background: #D97706;
}

.btn-sm {
  padding: 6px 12px;
  font-size: var(--text-xs);
}

.btn-lg {
  padding: var(--space-md) var(--space-xl);
  font-size: var(--text-base);
}

.actions {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
  margin-top: var(--space-md);
}

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--color-white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

th {
  background: var(--color-gray-50);
  padding: var(--space-md);
  text-align: left;
  font-weight: 600;
  font-size: var(--text-sm);
  color: var(--color-gray-600);
  white-space: nowrap;
}

td {
  padding: var(--space-md);
  border-bottom: 1px solid var(--color-gray-100);
  font-size: var(--text-sm);
  color: var(--color-gray-700);
}

tbody tr {
  transition: background-color var(--transition-fast);
}

tbody tr:hover {
  background: var(--color-gray-50);
}

tbody tr:last-child td {
  border-bottom: none;
}

.login-wrap {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-xl);
  background: linear-gradient(135deg, #EEF2FF 0%, #F0F9FF 50%, #FDF4FF 100%);
}

.login-card {
  width: min(420px, 100%);
  background: var(--color-white);
  border-radius: var(--radius-2xl);
  padding: var(--space-2xl);
  box-shadow: var(--shadow-xl);
}

.login-card-header {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.login-card-title {
  margin: 0 0 var(--space-sm);
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-gray-900);
}

.login-card-subtitle {
  margin: 0;
  font-size: var(--text-sm);
  color: var(--color-gray-500);
}

.toast {
  position: fixed;
  top: var(--space-xl);
  right: var(--space-xl);
  padding: var(--space-md);
  border-radius: var(--radius-lg);
  color: var(--color-white);
  font-size: var(--text-sm);
  font-weight: 500;
  z-index: 9999;
  animation: toastSlideIn 0.3s ease;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  min-width: 280px;
  max-width: 400px;
}

.toast svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.toast-success {
  background: var(--color-success);
}

.toast-error {
  background: var(--color-danger);
}

.toast-info {
  background: var(--color-info);
}

@keyframes toastSlideIn {
  from {
    opacity: 0;
    transform: translateX(20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes toastFadeOut {
  from {
    opacity: 1;
    transform: translateX(0);
  }
  to {
    opacity: 0;
    transform: translateX(20px);
  }
}

.toast {
  opacity: 0;
  transform: translateX(20px);
}

.toast.show {
  opacity: 1;
  transform: translateX(0);
  animation: toastSlideIn 0.3s ease;
}

.toast.hide {
  animation: toastFadeOut 0.25s ease forwards;
}

.muted {
  color: var(--color-gray-500);
  font-size: var(--text-sm);
}

.code-slab {
  background: var(--color-gray-900);
  color: var(--color-gray-100);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.6;
  max-width: 100%;
  -webkit-overflow-scrolling: touch;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border-radius: 20px;
  font-size: var(--text-xs);
  font-weight: 500;
}

.badge-success {
  background: rgba(16, 185, 129, 0.1);
  color: var(--color-success);
}

.badge-danger {
  background: rgba(239, 68, 68, 0.1);
  color: var(--color-danger);
}

.badge-warning {
  background: rgba(245, 158, 11, 0.1);
  color: var(--color-warning);
}

.badge-info {
  background: rgba(59, 130, 246, 0.1);
  color: var(--color-primary);
}

.divider {
  height: 1px;
  background: var(--color-gray-200);
  margin: var(--space-lg) 0;
}

.mobile-topbar {
  display: none;
}

.hamburger-btn {
  display: none;
}

.sidebar-overlay {
  display: none;
}

@media (max-width: 1024px) {
  .sidebar {
    width: 220px;
  }
  
  .main {
    margin-left: 220px;
    padding: var(--space-lg);
  }
  
  .grid {
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  }
}

@media (max-width: 768px) {
  .app-shell {
    flex-direction: column;
  }

  .sidebar {
    position: fixed;
    width: 280px;
    height: 100vh;
    padding: var(--space-lg);
    flex-direction: column;
    z-index: 100;
    transform: translateX(-100%);
    transition: transform var(--transition-normal);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 99;
  }

  .sidebar-overlay.open {
    display: block;
  }

  .mobile-topbar {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md);
    background: var(--color-gray-900);
    position: sticky;
    top: 0;
    z-index: 98;
  }

  .mobile-topbar h2 {
    margin: 0;
    font-size: var(--text-lg);
    font-weight: 700;
    color: var(--color-white);
  }

  .hamburger-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: none;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: var(--color-white);
    cursor: pointer;
    flex-shrink: 0;
  }

  .hamburger-btn svg {
    width: 22px;
    height: 22px;
  }

  .main {
    margin-left: 0;
    padding: var(--space-md);
  }

  .topbar {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-sm);
  }

  .grid {
    grid-template-columns: 1fr;
  }

  .login-card {
    padding: var(--space-lg);
  }

  .toast {
    right: var(--space-md);
    left: var(--space-md);
    min-width: auto;
  }

  table {
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
}

/* ===== Modal ===== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-md);
}

.modal {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.25);
  width: 100%;
  max-width: 480px;
  max-height: 90vh;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-lg);
  border-bottom: 1px solid var(--color-gray-200);
}

.modal-header h3 {
  margin: 0;
  font-size: var(--text-lg);
  font-weight: 600;
}

.modal-close {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1.2rem;
  color: var(--color-gray-400);
  padding: 4px;
  line-height: 1;
  border-radius: var(--radius-sm);
}

.modal-close:hover {
  background: var(--color-gray-100);
  color: var(--color-gray-700);
}

.modal-body {
  padding: var(--space-lg);
  flex: 1;
}

.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-lg);
  border-top: 1px solid var(--color-gray-200);
}