/* ============================================
   CSS VARIABLES - Design Tokens
   ============================================ */
:root {
  /* Colors */
  --color-primary: #6366f1;
  --color-primary-dark: #4f46e5;
  --color-primary-light: #818cf8;
  --color-secondary: #8b5cf6;
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-danger: #ef4444;
  --color-info: #3b82f6;

  /* Grayscale */
  --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;

  /* Background */
  --bg-primary: #ffffff;
  --bg-secondary: var(--color-gray-50);
  --bg-tertiary: var(--color-gray-100);

  /* Text */
  --text-primary: var(--color-gray-900);
  --text-secondary: var(--color-gray-600);
  --text-tertiary: var(--color-gray-500);

  /* Borders */
  --border-color: var(--color-gray-200);
  --border-radius: 8px;
  --border-radius-sm: 4px;
  --border-radius-lg: 12px;

  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;

  /* Typography */
  --font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
    Arial, sans-serif;
  --font-size-xs: 12px;
  --font-size-sm: 14px;
  --font-size-base: 16px;
  --font-size-lg: 18px;
  --font-size-xl: 20px;
  --font-size-2xl: 24px;
  --font-size-3xl: 30px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --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);

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 200ms ease-in-out;
  --transition-slow: 300ms ease-in-out;
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-secondary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
}

h1 {
  font-size: var(--font-size-3xl);
}
h2 {
  font-size: var(--font-size-2xl);
}
h3 {
  font-size: var(--font-size-xl);
}
h4 {
  font-size: var(--font-size-lg);
}
h5 {
  font-size: var(--font-size-base);
}
h6 {
  font-size: var(--font-size-sm);
}

p {
  margin-bottom: var(--spacing-md);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-dark);
}

/* ============================================
   LAYOUT
   ============================================ */
.container {
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.app-header {
  background: linear-gradient(135deg, #8b5cf6 0%, #6366f1 100%);
  border-bottom: none;
  padding: var(--spacing-lg) 0;
  box-shadow: 0 4px 12px rgba(139, 92, 246, 0.2);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.app-title {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin: 0;
  font-size: var(--font-size-2xl);
  color: white;
  font-weight: 700;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.app-title i {
  font-size: var(--font-size-xl);
}

.breadcrumbs {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-base);
  color: white;
  font-weight: 600;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

.breadcrumbs a {
  color: white;
  transition: all var(--transition-fast);
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

.breadcrumbs a:hover {
  color: white;
  text-decoration: underline;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.breadcrumbs .separator {
  color: rgba(255, 255, 255, 0.7);
}

.app-main {
  flex: 1;
  padding: var(--spacing-2xl) 0;
}

.app-footer {
  background-color: var(--bg-primary);
  border-top: 1px solid var(--border-color);
  padding: var(--spacing-lg) 0;
  text-align: center;
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
}

.app-footer p {
  margin: 0;
}

/* ============================================
   LOADING & ERROR STATES
   ============================================ */
.loading-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2xl);
  min-height: 400px;
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--color-gray-200);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.loading-container p {
  margin-top: var(--spacing-md);
  color: var(--text-secondary);
}

.error-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2xl);
  min-height: 400px;
  text-align: center;
}

.error-container i {
  font-size: var(--font-size-3xl);
  color: var(--color-danger);
  margin-bottom: var(--spacing-md);
}

.error-container p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
  max-width: 600px;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: var(--font-size-sm);
  font-weight: 500;
  border: none;
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-dark);
}

.btn-secondary {
  background-color: rgba(255, 255, 255, 0.2);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover:not(:disabled) {
  background-color: rgba(255, 255, 255, 0.3);
  border-color: rgba(255, 255, 255, 0.5);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

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

.btn-success:hover:not(:disabled) {
  background-color: #059669;
}

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

.btn-danger:hover:not(:disabled) {
  background-color: #dc2626;
}

.btn-sm {
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: var(--font-size-xs);
}

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

/* ============================================
   GRID SYSTEM
   ============================================ */
.grid {
  display: grid;
  gap: var(--spacing-lg);
}

.grid-cols-1 {
  grid-template-columns: repeat(1, 1fr);
}
.grid-cols-2 {
  grid-template-columns: repeat(2, 1fr);
}
.grid-cols-3 {
  grid-template-columns: repeat(3, 1fr);
}
.grid-cols-4 {
  grid-template-columns: repeat(4, 1fr);
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.text-center {
  text-align: center;
}
.text-left {
  text-align: left;
}
.text-right {
  text-align: right;
}

.text-primary {
  color: var(--text-primary);
}
.text-secondary {
  color: var(--text-secondary);
}
.text-tertiary {
  color: var(--text-tertiary);
}

.text-success {
  color: var(--color-success);
}
.text-warning {
  color: var(--color-warning);
}
.text-danger {
  color: var(--color-danger);
}
.text-info {
  color: var(--color-info);
}

.font-bold {
  font-weight: 600;
}
.font-normal {
  font-weight: 400;
}

.mt-xs {
  margin-top: var(--spacing-xs);
}
.mt-sm {
  margin-top: var(--spacing-sm);
}
.mt-md {
  margin-top: var(--spacing-md);
}
.mt-lg {
  margin-top: var(--spacing-lg);
}
.mt-xl {
  margin-top: var(--spacing-xl);
}

.mb-xs {
  margin-bottom: var(--spacing-xs);
}
.mb-sm {
  margin-bottom: var(--spacing-sm);
}
.mb-md {
  margin-bottom: var(--spacing-md);
}
.mb-lg {
  margin-bottom: var(--spacing-lg);
}
.mb-xl {
  margin-bottom: var(--spacing-xl);
}

.hidden {
  display: none;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 1024px) {
  .grid-cols-4 {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacing-md);
  }

  .header-content {
    flex-direction: column;
    align-items: flex-start;
  }

  .grid-cols-3,
  .grid-cols-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .grid-cols-2,
  .grid-cols-3,
  .grid-cols-4 {
    grid-template-columns: 1fr;
  }

  .app-title {
    font-size: var(--font-size-xl);
  }
}