/* ============================================
   GridMind - AI Training Platform for Utilities
   Design System & Styles
   ============================================ */

/* CSS Variables */
:root {
  /* Colors */
  --color-primary: #0066CC;
  --color-secondary: #1A2B4C;
  --color-success: #00875A;
  --color-warning: #F5A623;
  --color-text: #2D3748;
  --color-text-light: #718096;
  --color-background: #F7F9FC;
  --color-card: #FFFFFF;
  --color-border: #D1D9E3;

  /* Role Colors */
  --color-field-tech: #00875A;
  --color-csr: #0066CC;
  --color-grid-op: #F5A623;
  --color-billing: #9B59B6;
  --color-engineer: #E74C3C;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.05), 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
}

/* Reset & Base */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-background);
  min-height: 100vh;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
  color: var(--color-secondary);
}

h1 {
  font-size: 2.5rem;
  font-weight: 700;
}

h2 {
  font-size: 1.875rem;
  font-weight: 600;
}

h3 {
  font-size: 1.25rem;
  font-weight: 600;
}

h4 {
  font-size: 1.125rem;
  font-weight: 600;
}

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

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

a:hover {
  color: var(--color-secondary);
}

/* Layout */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.container-sm {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* Header */
.header {
  background: var(--color-card);
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-md) 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-secondary);
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-success));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--color-text-light);
  font-weight: 500;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.nav-link:hover {
  color: var(--color-primary);
  background: var(--color-background);
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, var(--color-secondary) 0%, #2d4a6f 100%);
  color: white;
  padding: var(--spacing-3xl) 0;
  text-align: center;
}

.hero h1 {
  color: white;
  margin-bottom: var(--spacing-lg);
  font-size: 2.75rem;
}

.hero-subtitle {
  font-size: 1.25rem;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto var(--spacing-xl);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: 12px 24px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

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

.btn-primary:hover {
  background: #0052a3;
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: var(--color-card);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

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

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

.btn-success:hover {
  background: #006b47;
  color: white;
  transform: translateY(-2px);
}

.btn-lg {
  padding: 16px 32px;
  font-size: 1.125rem;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 0.875rem;
}

/* Cards */
.card {
  background: var(--color-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  padding: var(--spacing-lg);
  transition: all var(--transition-normal);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.card-clickable {
  cursor: pointer;
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-md);
  color: white;
  font-size: 1.5rem;
}

.card-title {
  margin-bottom: var(--spacing-sm);
}

.card-description {
  color: var(--color-text-light);
  margin-bottom: var(--spacing-md);
}

/* Value Props Section */
.value-props {
  padding: var(--spacing-3xl) 0;
}

.value-props-title {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
}

.value-props-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-xl);
}

.value-prop-card {
  text-align: center;
  padding: var(--spacing-xl);
}

.value-prop-card .card-icon {
  margin: 0 auto var(--spacing-md);
}

/* Roles Grid */
.roles-section {
  padding: var(--spacing-3xl) 0;
}

.roles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--spacing-lg);
}

.role-card {
  display: flex;
  flex-direction: column;
}

.role-card .card-icon {
  width: 56px;
  height: 56px;
  font-size: 1.75rem;
}

.role-meta {
  display: flex;
  gap: var(--spacing-lg);
  margin-top: auto;
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--color-border);
  font-size: 0.875rem;
  color: var(--color-text-light);
}

.role-meta span {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

/* Progress Bar */
.progress-bar-container {
  background: var(--color-border);
  border-radius: var(--radius-full);
  height: 8px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-success));
  border-radius: var(--radius-full);
  transition: width var(--transition-normal);
}

.progress-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-sm);
  font-size: 0.875rem;
}

.progress-label {
  font-weight: 500;
}

.progress-percentage {
  color: var(--color-text-light);
}

/* Training Path Page */
.path-header {
  padding: var(--spacing-2xl) 0;
  background: var(--color-card);
  border-bottom: 1px solid var(--color-border);
}

.path-title {
  margin-bottom: var(--spacing-md);
}

.path-stats {
  display: flex;
  gap: var(--spacing-xl);
  color: var(--color-text-light);
  font-size: 0.875rem;
  margin-bottom: var(--spacing-lg);
}

.path-stats span {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.modules-section {
  padding: var(--spacing-2xl) 0;
}

.modules-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.module-card {
  display: flex;
  gap: var(--spacing-lg);
  align-items: flex-start;
}

.module-number {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.25rem;
  flex-shrink: 0;
}

.module-number.completed {
  background: var(--color-success);
  color: white;
}

.module-number.in-progress {
  background: var(--color-primary);
  color: white;
}

.module-number.locked {
  background: var(--color-border);
  color: var(--color-text-light);
}

.module-content {
  flex: 1;
}

.module-title {
  margin-bottom: var(--spacing-xs);
}

.module-description {
  color: var(--color-text-light);
  margin-bottom: var(--spacing-sm);
}

.module-meta {
  display: flex;
  gap: var(--spacing-md);
  font-size: 0.875rem;
  color: var(--color-text-light);
}

.module-meta span {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

/* Status Badge */
.status-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.status-badge.completed {
  background: rgba(0, 135, 90, 0.1);
  color: var(--color-success);
}

.status-badge.in-progress {
  background: rgba(0, 102, 204, 0.1);
  color: var(--color-primary);
}

.status-badge.locked {
  background: var(--color-background);
  color: var(--color-text-light);
}

/* Lesson Page */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) 0;
  font-size: 0.875rem;
  color: var(--color-text-light);
}

.breadcrumb a {
  color: var(--color-primary);
}

.breadcrumb-separator {
  opacity: 0.5;
}

.lesson-header {
  padding: var(--spacing-xl) 0;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-card);
}

.lesson-context {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-bottom: var(--spacing-sm);
}

.lesson-title {
  margin-bottom: var(--spacing-md);
}

.lesson-progress {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  font-size: 0.875rem;
  color: var(--color-text-light);
}

.lesson-content {
  padding: var(--spacing-2xl) 0;
}

.lesson-body {
  max-width: 720px;
}

.lesson-intro {
  font-size: 1.125rem;
  color: var(--color-text);
  margin-bottom: var(--spacing-xl);
  line-height: 1.7;
}

.lesson-section {
  margin-bottom: var(--spacing-2xl);
}

.lesson-section h3 {
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-bottom: 2px solid var(--color-border);
}

.key-points-list {
  list-style: none;
}

.key-points-list li {
  padding: var(--spacing-sm) 0;
  padding-left: var(--spacing-lg);
  position: relative;
}

.key-points-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 8px;
  height: 8px;
  background: var(--color-primary);
  border-radius: var(--radius-full);
}

/* AI Prompt Card */
.prompt-card {
  background: var(--color-background);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
  border-left: 4px solid var(--color-primary);
}

.prompt-card-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
}

.prompt-card-icon {
  width: 32px;
  height: 32px;
  background: var(--color-primary);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 0.875rem;
}

.prompt-card-title {
  font-weight: 600;
  color: var(--color-secondary);
}

.prompt-text {
  background: var(--color-secondary);
  color: #e2e8f0;
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
  font-size: 0.875rem;
  line-height: 1.6;
  margin-bottom: var(--spacing-md);
  white-space: pre-wrap;
  word-wrap: break-word;
}

.prompt-explanation {
  font-size: 0.875rem;
  color: var(--color-text-light);
  font-style: italic;
}

/* Tips Section */
.tips-list {
  background: rgba(0, 135, 90, 0.05);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  border-left: 4px solid var(--color-success);
}

.tips-list-title {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
  color: var(--color-success);
  font-weight: 600;
}

.tips-list ul {
  list-style: none;
}

.tips-list li {
  padding: var(--spacing-sm) 0;
  padding-left: var(--spacing-lg);
  position: relative;
  color: var(--color-text);
}

.tips-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: calc(var(--spacing-sm) + 8px);
  width: 6px;
  height: 6px;
  background: var(--color-success);
  border-radius: var(--radius-full);
}

/* Lesson Navigation */
.lesson-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-xl) 0;
  border-top: 1px solid var(--color-border);
  margin-top: var(--spacing-2xl);
  gap: var(--spacing-md);
}

.lesson-nav-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--radius-md);
  font-weight: 500;
  transition: all var(--transition-fast);
}

.lesson-nav-btn.prev {
  color: var(--color-text-light);
}

.lesson-nav-btn.prev:hover {
  color: var(--color-text);
  background: var(--color-background);
}

.lesson-nav-btn.disabled {
  opacity: 0.5;
  pointer-events: none;
}

/* CTA Section */
.cta-section {
  padding: var(--spacing-3xl) 0;
  text-align: center;
  background: var(--color-card);
  border-top: 1px solid var(--color-border);
}

.cta-title {
  margin-bottom: var(--spacing-md);
}

.cta-description {
  color: var(--color-text-light);
  max-width: 500px;
  margin: 0 auto var(--spacing-xl);
}

/* Footer */
.footer {
  background: var(--color-secondary);
  color: rgba(255, 255, 255, 0.7);
  padding: var(--spacing-xl) 0;
  text-align: center;
}

.footer-content {
  font-size: 0.875rem;
}

/* Loading State */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-3xl);
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: var(--radius-full);
  animation: spin 1s linear infinite;
}

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

/* Empty State */
.empty-state {
  text-align: center;
  padding: var(--spacing-3xl);
  color: var(--color-text-light);
}

.empty-state-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-md);
  opacity: 0.5;
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.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-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 !important; }

/* Responsive Design */
@media (max-width: 768px) {
  h1 {
    font-size: 2rem;
  }

  h2 {
    font-size: 1.5rem;
  }

  .hero {
    padding: var(--spacing-2xl) 0;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .container {
    padding: 0 var(--spacing-md);
  }

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

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

  .module-card {
    flex-direction: column;
    align-items: stretch;
  }

  .module-number {
    width: 40px;
    height: 40px;
    font-size: 1rem;
  }

  .lesson-nav {
    flex-direction: column;
  }

  .lesson-nav-btn {
    width: 100%;
    justify-content: center;
  }

  .path-stats {
    flex-direction: column;
    gap: var(--spacing-sm);
  }
}

@media (max-width: 480px) {
  .header-content {
    flex-direction: column;
    gap: var(--spacing-md);
  }

  .btn-lg {
    width: 100%;
  }

  .role-meta {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .prompt-text {
    font-size: 0.8rem;
  }
}

/* Icon utilities (SVG inline styling) */
.icon {
  width: 1em;
  height: 1em;
  display: inline-block;
  vertical-align: middle;
}

.icon-sm { font-size: 1rem; }
.icon-md { font-size: 1.5rem; }
.icon-lg { font-size: 2rem; }