/* ============================================
   GLOBAL STYLES
   Purpose: Core styles used across all pages
   GitHub Dark Mode + VS Code Aesthetic
   ============================================ */

/* ============================================
   CSS VARIABLES
   ============================================ */
:root {
  /* GitHub Dark Mode Colors */
  --bg-primary: #0d1117;
  --bg-secondary: #161b22;
  --bg-tertiary: #21262d;
  --bg-overlay: rgba(13, 17, 23, 0.95);
  
  /* Borders */
  --border-primary: #30363d;
  --border-secondary: #21262d;
  --border-glow: rgba(88, 166, 255, 0.4);
  
  /* Text Colors */
  --text-primary: #c9d1d9;
  --text-secondary: #8b949e;
  --text-tertiary: #6e7681;
  --text-white: #ffffff;
  
  /* Accent Colors (VS Code inspired) */
  --accent-blue: #58a6ff;
  --accent-green: #7ee787;
  --accent-purple: #bc8cff;
  --accent-orange: #ffa657;
  --accent-red: #ff7b72;
  --accent-yellow: #d29922;
  
  /* Typography */
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', 'Monaco', monospace;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
  
  /* Font Sizes */
  --font-hero: 48px;
  --font-title: 32px;
  --font-heading: 24px;
  --font-subheading: 18px;
  --font-body: 16px;
  --font-small: 14px;
  --font-tiny: 12px;
  
  /* Spacing */
  --spacing-xs: 8px;
  --spacing-sm: 16px;
  --spacing-md: 24px;
  --spacing-lg: 32px;
  --spacing-xl: 48px;
  --spacing-xxl: 64px;
  
  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  
  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 20px rgba(88, 166, 255, 0.3);
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  
  /* Z-index */
  --z-background: -1;
  --z-content: 1;
  --z-nav: 100;
  --z-modal: 1000;
}

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

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

body {
  font-family: var(--font-sans);
  font-size: var(--font-body);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-mono);
  font-weight: 600;
  line-height: 1.2;
  color: var(--text-white);
}

/* Mobile first - smaller sizes */
h1 {
  font-size: 28px;
  word-break: break-word;
}

h2 {
  font-size: 24px;
  word-break: break-word;
}

h3 {
  font-size: 20px;
  word-break: break-word;
}

h4 {
  font-size: 18px;
  word-break: break-word;
}

/* Desktop - larger sizes */
@media (min-width: 768px) {
  h1 {
    font-size: 48px;
  }
  
  h2 {
    font-size: 32px;
  }
  
  h3 {
    font-size: 24px;
  }
  
  h4 {
    font-size: 20px;
  }
}

@media (min-width: 1024px) {
  h1 {
    font-size: 56px;
  }
  
  h2 {
    font-size: 40px;
  }
  
  h3 {
    font-size: 28px;
  }
}

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

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

a:hover {
  color: var(--accent-green);
}

code {
  font-family: var(--font-mono);
  background: var(--bg-tertiary);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.9em;
  color: var(--accent-orange);
  word-break: break-word;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: 12px 24px;
  font-family: var(--font-mono);
  font-size: var(--font-body);
  font-weight: 500;
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  color: var(--text-primary);
  cursor: pointer;
  transition: all var(--transition-normal);
  text-align: center;
  min-height: 44px;
}

.btn:hover {
  background: var(--bg-tertiary);
  border-color: var(--accent-blue);
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

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

.btn-primary {
  background: var(--accent-blue);
  border-color: var(--accent-blue);
  color: var(--bg-primary);
}

.btn-primary:hover {
  background: var(--accent-green);
  border-color: var(--accent-green);
}

.btn-secondary {
  background: transparent;
  border-color: var(--border-primary);
  color: var(--text-primary);
}

.btn-success {
  background: var(--accent-green);
  border-color: var(--accent-green);
  color: var(--bg-primary);
}

.btn-danger {
  background: var(--accent-red);
  border-color: var(--accent-red);
  color: var(--text-white);
}

.btn-icon {
  padding: 10px;
  min-width: 44px;
}

.btn-large {
  padding: 16px 32px;
  font-size: var(--font-subheading);
  min-height: 56px;
}

@media (min-width: 768px) {
  .btn {
    padding: 14px 28px;
  }
  
  .btn-large {
    padding: 18px 40px;
    font-size: var(--font-heading);
    min-height: 64px;
  }
}

/* ============================================
   INPUTS & FORMS
   ============================================ */
input,
textarea,
select {
  width: 100%;
  padding: 12px 16px;
  font-family: var(--font-sans);
  font-size: var(--font-body);
  color: var(--text-primary);
  background: var(--bg-secondary);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

input:focus,
textarea:focus,
select:focus {
  outline: none;
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.1);
}

input::placeholder,
textarea::placeholder {
  color: var(--text-tertiary);
}

label {
  display: block;
  margin-bottom: var(--spacing-xs);
  font-size: var(--font-small);
  font-weight: 500;
  color: var(--text-secondary);
}

.form-group {
  margin-bottom: var(--spacing-md);
}

/* ============================================
   CARDS
   ============================================ */
.card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  transition: all var(--transition-normal);
}

.card:hover {
  border-color: var(--accent-blue);
  box-shadow: var(--shadow-glow);
  transform: translateY(-4px);
}

@media (min-width: 768px) {
  .card {
    padding: var(--spacing-lg);
  }
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

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

.text-center {
  text-align: center;
}

.text-mono {
  font-family: var(--font-mono);
}

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

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

.text-accent {
  color: var(--accent-blue);
}

.text-success {
  color: var(--accent-green);
}

.text-warning {
  color: var(--accent-orange);
}

.text-danger {
  color: var(--accent-red);
}

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }

/* ============================================
   BACK BUTTON
   ============================================ */
.back-button {
  position: fixed;
  top: var(--spacing-md);
  left: var(--spacing-md);
  z-index: var(--z-nav);
}

.back-button .btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: 10px 16px;
  font-size: var(--font-small);
}

@media (min-width: 768px) {
  .back-button {
    top: var(--spacing-lg);
    left: var(--spacing-lg);
  }
  
  .back-button .btn {
    padding: 12px 20px;
    font-size: var(--font-body);
  }
}

/* ============================================
   LANGUAGE TOGGLE
   ============================================ */
.language-toggle {
  position: fixed;
  top: var(--spacing-md);
  right: var(--spacing-md);
  display: flex;
  gap: var(--spacing-xs);
  z-index: var(--z-nav);
}

.language-toggle .btn {
  padding: 8px 16px;
  font-size: var(--font-small);
  min-height: auto;
}

.language-toggle .btn.active {
  background: var(--accent-blue);
  border-color: var(--accent-blue);
  color: var(--bg-primary);
}

@media (min-width: 768px) {
  .language-toggle {
    top: var(--spacing-lg);
    right: var(--spacing-lg);
  }
}

/* ============================================
   LOADING OVERLAY
   ============================================ */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--bg-overlay);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.loading-overlay.active {
  opacity: 1;
  visibility: visible;
}

.loading-spinner {
  width: 48px;
  height: 48px;
  border: 3px solid var(--border-primary);
  border-top-color: var(--accent-blue);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

/* ============================================
   TOAST NOTIFICATIONS
   ============================================ */
.toast-container {
  position: fixed;
  top: var(--spacing-md);
  right: var(--spacing-md);
  z-index: var(--z-modal);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  max-width: calc(100vw - 32px);
}

.toast {
  background: var(--bg-secondary);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-md);
  padding: var(--spacing-sm) var(--spacing-md);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  min-width: 280px;
  max-width: 400px;
  animation: slideIn 0.3s ease;
}

.toast-success {
  border-color: var(--accent-green);
  background: rgba(126, 231, 135, 0.1);
}

.toast-error {
  border-color: var(--accent-red);
  background: rgba(255, 123, 114, 0.1);
}

.toast-warning {
  border-color: var(--accent-orange);
  background: rgba(255, 166, 87, 0.1);
}

.toast-message {
  flex: 1;
  font-size: var(--font-small);
  color: var(--text-primary);
  word-break: break-word;
}

.toast-close {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 20px;
  padding: 0;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--transition-fast);
  flex-shrink: 0;
}

.toast-close:hover {
  color: var(--text-primary);
}

@keyframes slideIn {
  from {
    transform: translateX(400px);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

@media (min-width: 768px) {
  .toast-container {
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    max-width: 400px;
  }
  
  .toast {
    min-width: 300px;
  }
}

/* ============================================
   ANIMATIONS
   ============================================ */
@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

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

@keyframes glow {
  0%, 100% {
    box-shadow: 0 0 10px rgba(88, 166, 255, 0.3);
  }
  50% {
    box-shadow: 0 0 20px rgba(88, 166, 255, 0.6);
  }
}

.fade-in {
  animation: fadeIn var(--transition-slow);
}

.fade-in-up {
  animation: fadeInUp var(--transition-slow);
}

/* ============================================
   SCROLLBAR STYLING
   ============================================ */
::-webkit-scrollbar {
  width: 12px;
}

::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
  background: var(--bg-tertiary);
  border-radius: 6px;
  border: 2px solid var(--bg-primary);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--border-primary);
}

/* Firefox */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--bg-tertiary) var(--bg-primary);
}

/* ============================================
   ACCESSIBILITY
   ============================================ */
.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;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--accent-blue);
  color: var(--bg-primary);
  padding: var(--spacing-sm) var(--spacing-md);
  z-index: var(--z-modal);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 0;
}

/* Focus visible for keyboard navigation */
*:focus-visible {
  outline: 2px solid var(--accent-blue);
  outline-offset: 2px;
}

/* ============================================
   PRINT STYLES
   ============================================ */
@media print {
  body {
    background: white;
    color: black;
  }
  
  .language-toggle,
  .back-button,
  .loading-overlay,
  .toast-container {
    display: none;
  }
}

/* ============================================
   BACKGROUND CANVAS
   ============================================ */
#bg-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: var(--z-background);
  opacity: 0.6;
}

/* ============================================
   CODE BLOCK HEADER (Used across all pages)
   ============================================ */
.code-block-header {
  background: var(--bg-secondary);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  font-family: var(--font-mono);
  font-size: var(--font-tiny);
  line-height: 1.8;
  margin-bottom: var(--spacing-lg);
  text-align: left;
  overflow-x: auto;
}

@media (min-width: 768px) {
  .code-block-header {
    padding: var(--spacing-lg);
    font-size: var(--font-small);
  }
}

@media (min-width: 1024px) {
  .code-block-header {
    font-size: var(--font-body);
    margin-bottom: var(--spacing-xl);
  }
}

.code-block-header .code-line {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
}

.code-block-header .code-indent {
  padding-left: var(--spacing-sm);
}

@media (min-width: 768px) {
  .code-block-header .code-indent {
    padding-left: var(--spacing-md);
  }
}

@media (min-width: 1024px) {
  .code-block-header .code-indent {
    padding-left: var(--spacing-lg);
  }
}

.code-key {
  color: var(--accent-purple);
  font-weight: 500;
}

.code-variable {
  color: var(--text-white);
}

.code-bracket {
  color: var(--accent-yellow);
}

.code-symbol {
  color: var(--text-secondary);
}

.code-number {
  color: var(--accent-orange);
}

.code-string {
  color: var(--accent-green);
}

.code-comment {
  color: var(--text-tertiary);
  font-style: italic;
}

.code-value {
  color: var(--accent-blue);
}