/* ===================================
   CSS Custom Properties (Design Tokens)
   =================================== */

:root {
  /* Color Palette */
  --color-primary: #FF9900;
  --color-primary-dark: #E88B00;
  --color-secondary: #232F3E;
  --color-secondary-light: #37475A;
  --color-background: #F8F9FA;
  --color-background-alt: #FFFFFF;
  --color-text: #343A40;
  --color-text-light: #6C757D;
  --color-success: #28A745;
  --color-border: #E9ECEF;
  --color-accent: #146EB4;
  
  /* Spacing Scale */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  
  /* Border & Shadow */
  --border-radius: 12px;
  --border-radius-sm: 6px;
  --border-radius-lg: 16px;
  --box-shadow-light: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);
  --box-shadow-medium: 0 4px 6px rgba(0, 0, 0, 0.07), 0 2px 4px rgba(0, 0, 0, 0.06);
  --box-shadow-large: 0 10px 15px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);
  --box-shadow-hover: 0 20px 25px rgba(0, 0, 0, 0.1), 0 10px 10px rgba(0, 0, 0, 0.04);
  
  /* Typography */
  --font-family-base: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-family-mono: "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Consolas, "Courier New", monospace;
  
  --font-size-base: 1rem;
  --font-size-sm: 0.875rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2.25rem;
  --font-size-4xl: 3rem;
  
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  
  --line-height-tight: 1.25;
  --line-height-base: 1.5;
  --line-height-relaxed: 1.7;
}

/* ===================================
   CSS Reset & Base Styles
   =================================== */

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

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

body {
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  line-height: var(--line-height-base);
  color: var(--color-text);
  background: linear-gradient(135deg, #F8F9FA 0%, #E9ECEF 100%);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ===================================
   Typography
   =================================== */

h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--color-secondary);
  letter-spacing: -0.02em;
}

h1 {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--spacing-sm);
  font-weight: var(--font-weight-bold);
}

@media (min-width: 768px) {
  h1 {
    font-size: var(--font-size-4xl);
  }
}

h2 {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--spacing-md);
  font-weight: var(--font-weight-semibold);
}

h3 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--spacing-xs);
  font-weight: var(--font-weight-semibold);
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

a:focus {
  outline: 3px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: 2px;
}

a:focus-visible {
  outline: 3px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: 2px;
}

code {
  font-family: var(--font-family-mono);
  font-size: 0.9em;
  background-color: rgba(0, 0, 0, 0.05);
  padding: 0.125rem 0.25rem;
  border-radius: 3px;
}

/* ===================================
   Layout Components
   =================================== */

/* Header */
body > header[role="banner"] {
  background: linear-gradient(135deg, #232F3E 0%, #37475A 100%);
  color: var(--color-background-alt);
  padding: var(--spacing-2xl) var(--spacing-md);
  text-align: center;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  position: relative;
  overflow: hidden;
}

body > header[role="banner"]::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 20% 50%, rgba(255, 153, 0, 0.1) 0%, transparent 50%),
              radial-gradient(circle at 80% 50%, rgba(20, 110, 180, 0.1) 0%, transparent 50%);
  pointer-events: none;
}

body > header[role="banner"] h1 {
  color: var(--color-background-alt);
  margin-bottom: var(--spacing-sm);
  position: relative;
  z-index: 1;
  font-size: var(--font-size-3xl);
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

@media (min-width: 768px) {
  body > header[role="banner"] h1 {
    font-size: var(--font-size-4xl);
  }
}

body > header[role="banner"] p {
  color: rgba(255, 255, 255, 0.95);
  font-size: var(--font-size-lg);
  margin-bottom: 0;
  position: relative;
  z-index: 1;
  font-weight: var(--font-weight-normal);
  letter-spacing: 0.01em;
}

/* Main Content */
main {
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--spacing-2xl) var(--spacing-md);
  flex: 1;
}

.repository-collection h2 {
  text-align: center;
  margin-bottom: var(--spacing-xl);
  color: var(--color-secondary);
  position: relative;
  display: inline-block;
  left: 50%;
  transform: translateX(-50%);
}

.repository-collection h2::after {
  content: '';
  position: absolute;
  bottom: -0.5rem;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary) 0%, var(--color-accent) 100%);
  border-radius: 2px;
}

/* Footer */
footer {
  background: linear-gradient(135deg, #232F3E 0%, #37475A 100%);
  color: var(--color-background-alt);
  padding: var(--spacing-lg) var(--spacing-md);
  text-align: center;
  margin-top: auto;
  box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.05);
}

footer p {
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: 0;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
}

/* ===================================
   Responsive Grid Layout (Mobile-First)
   =================================== */

.repository-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
  padding: 0;
}

/* Tablet breakpoint: 768px and up */
@media (min-width: 768px) {
  .repository-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
  }
  
  main {
    padding: var(--spacing-2xl) var(--spacing-lg);
  }
  
  body > header[role="banner"] {
    padding: var(--spacing-2xl) var(--spacing-lg);
  }
  
  body > header[role="banner"] h1 {
    font-size: var(--font-size-4xl);
  }
}

/* Desktop breakpoint: 1024px and up */
@media (min-width: 1024px) {
  .repository-grid {
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-xl);
  }
  
  main {
    padding: var(--spacing-2xl);
  }
  
  body > header[role="banner"] {
    padding: var(--spacing-2xl);
  }
}

/* ===================================
   Repository Card Component
   =================================== */

.repository-card {
  background: var(--color-background-alt);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--box-shadow-medium);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), 
              box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  height: 100%;
  border: 1px solid var(--color-border);
  position: relative;
  overflow: hidden;
}

.repository-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary) 0%, var(--color-accent) 100%);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.repository-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--box-shadow-hover);
  border-color: var(--color-primary);
}

.repository-card:hover::before {
  transform: scaleX(1);
}

/* Card Header */
.repository-header {
  margin-bottom: var(--spacing-md);
}

.repository-title {
  color: var(--color-secondary);
  margin: 0 0 var(--spacing-sm) 0;
  font-size: var(--font-size-2xl);
  line-height: var(--line-height-tight);
  font-weight: var(--font-weight-bold);
  transition: color 0.2s ease;
}

.repository-card:hover .repository-title {
  color: var(--color-primary);
}

.repository-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-sm);
}

.tag {
  display: inline-block;
  padding: 0.25rem 0.625rem;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  border-radius: var(--border-radius-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.tag-aws {
  background-color: #FF9900;
  color: #FFFFFF;
}

.tag-feature {
  background-color: #8B5CF6;
  color: #FFFFFF;
}

.tag-framework {
  background-color: #146EB4;
  color: #FFFFFF;
}

.tag-iac {
  background-color: #28A745;
  color: #FFFFFF;
}

.repository-card:hover .tag {
  transform: translateY(-2px);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.15);
}

.repository-name {
  color: var(--color-text-light);
  margin: 0;
  font-size: var(--font-size-sm);
  line-height: var(--line-height-base);
  font-weight: var(--font-weight-normal);
  font-family: var(--font-family-mono);
  word-break: break-word;
  opacity: 0.8;
}

/* Card Description */
.repository-description {
  color: var(--color-text);
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  margin: 0 0 var(--spacing-lg) 0;
  flex-grow: 1;
}

/* Card Footer */
.repository-footer {
  margin-top: auto;
  padding-top: var(--spacing-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.github-link {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-lg);
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: var(--color-background-alt);
  border-radius: var(--border-radius);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  text-decoration: none;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 2px 4px rgba(255, 153, 0, 0.2);
  position: relative;
  overflow: hidden;
}

.github-link::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, var(--color-secondary) 0%, var(--color-secondary-light) 100%);
  opacity: 0;
  transition: opacity 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  border-radius: var(--border-radius);
}

.github-link:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(255, 153, 0, 0.3);
}

.github-link:hover::before {
  opacity: 1;
}

.github-link span:not(.sr-only) {
  position: relative;
  z-index: 1;
}

.github-link::after {
  content: '→';
  position: relative;
  z-index: 1;
  font-size: var(--font-size-lg);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  display: inline-block;
}

.github-link:hover::after {
  transform: translateX(4px);
}

.github-link:focus {
  outline: 3px solid var(--color-secondary);
  outline-offset: 3px;
  box-shadow: 0 0 0 3px rgba(255, 153, 0, 0.3);
}

.github-link:focus-visible {
  outline: 3px solid var(--color-secondary);
  outline-offset: 3px;
  box-shadow: 0 0 0 3px rgba(255, 153, 0, 0.3);
}

/* ===================================
   Accessibility Enhancements
   =================================== */

/* Skip to main content link for screen readers and keyboard users */
.skip-to-content {
  position: absolute;
  top: -100px;
  left: 0;
  background-color: var(--color-primary);
  color: var(--color-white);
  padding: var(--spacing-sm) var(--spacing-md);
  text-decoration: none;
  font-weight: 600;
  z-index: 9999;
  border-radius: 0 0 var(--border-radius) 0;
}

.skip-to-content:focus {
  top: 0;
  outline: 3px solid var(--color-secondary);
  outline-offset: 3px;
}

/* Enhanced focus indicators for all interactive elements */
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: 2px;
}

/* Ensure sufficient color contrast for all text */
/* Primary text on white background: #343A40 on #FFFFFF = 11.24:1 (Passes AAA) */
/* Secondary text on white background: #232F3E on #FFFFFF = 13.54:1 (Passes AAA) */
/* White text on secondary background: #FFFFFF on #232F3E = 13.54:1 (Passes AAA) */
/* Primary orange on white: #FF9900 on #FFFFFF = 2.93:1 (Fails - needs adjustment for text) */

/* Adjusted link color for better contrast when used as text */
.accessible-link-text {
  color: #D97706; /* Darker orange for 4.5:1 contrast ratio */
}

/* Repository card hover state maintains accessibility */
.repository-card:focus-within {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --color-primary: #CC7A00;
    --color-text: #000000;
    --box-shadow-light: 0 2px 4px rgba(0, 0, 0, 0.3);
    --box-shadow-medium: 0 4px 8px rgba(0, 0, 0, 0.4);
  }
  
  .repository-card {
    border: 2px solid var(--color-secondary);
  }
  
  a:focus,
  a:focus-visible,
  button:focus-visible {
    outline-width: 4px;
  }
}

/* Reduced motion support for users with vestibular disorders */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  
  html {
    scroll-behavior: auto;
  }
  
  .repository-card {
    animation: none;
  }
  
  .repository-card:hover {
    transform: none;
  }
  
  .github-link:hover {
    transform: none;
  }
  
  .github-link:hover::after {
    transform: none;
  }
}

/* Screen reader only content */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* Focus visible polyfill for older browsers */
.js-focus-visible :focus:not(.focus-visible) {
  outline: none;
}

/* ===================================
   Animations & Visual Enhancements
   =================================== */

/* Fade in animation for cards */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.repository-card {
  animation: fadeInUp 0.6s cubic-bezier(0.4, 0, 0.2, 1) backwards;
}

.repository-card:nth-child(1) { animation-delay: 0.1s; }
.repository-card:nth-child(2) { animation-delay: 0.2s; }
.repository-card:nth-child(3) { animation-delay: 0.3s; }
.repository-card:nth-child(4) { animation-delay: 0.4s; }
.repository-card:nth-child(5) { animation-delay: 0.5s; }
.repository-card:nth-child(6) { animation-delay: 0.6s; }

/* Smooth scroll behavior */
html {
  scroll-behavior: smooth;
}

/* Selection styling */
::selection {
  background-color: var(--color-primary);
  color: var(--color-background-alt);
}

::-moz-selection {
  background-color: var(--color-primary);
  color: var(--color-background-alt);
}

/* Loading state for images */
img {
  display: block;
  max-width: 100%;
  height: auto;
}

/* Badge/Tag styling (for future use) */
.badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  border-radius: var(--border-radius-sm);
  background-color: var(--color-background);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

/* Utility classes */
.text-center {
  text-align: center;
}

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

.mt-auto {
  margin-top: auto;
}