/* =====================================================
   R63 TUTORIAL REDESIGN - Modern Documentation Style
   ===================================================== */

/* Reset & Variables */
:root {
  /* Colors - GitHub-inspired */
  --color-bg-primary: #0d1117;
  --color-bg-secondary: #161b22;
  --color-bg-tertiary: #21262d;
  --color-border: #30363d;
  --color-border-light: #21262d;
  --color-text-primary: #e6edf3;
  --color-text-secondary: #8b949e;
  --color-text-muted: #6e7681;
  --color-accent-blue: #58a6ff;
  --color-accent-green: #3fb950;
  --color-accent-orange: #d29922;
  --color-accent-red: #f85149;
  --color-accent-purple: #a371f7;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  
  /* Layout */
  --sidebar-width: 280px;
  --topnav-height: 64px;
  --content-max-width: 1000px;
  
  /* Typography */
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Courier New', monospace;
  
  /* 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);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--topnav-height) + var(--spacing-lg));
}

body {
  font-family: var(--font-body);
  background: var(--color-bg-primary);
  color: var(--color-text-primary);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* =====================================================
   TOP NAVIGATION
   ===================================================== */

.top-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--topnav-height);
  background: var(--color-bg-secondary);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  backdrop-filter: blur(10px);
}

.nav-container {
  max-width: 100%;
  height: 100%;
  padding: 0 var(--spacing-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  text-decoration: none;
  color: var(--color-text-primary);
  font-weight: 600;
  transition: opacity 0.2s ease;
}

.nav-logo:hover {
  opacity: 0.8;
}

.nav-logo img {
  width: 32px;
  height: 32px;
  border-radius: 6px;
}

.nav-title {
  font-size: 1.1rem;
  font-weight: 600;
}

.nav-actions {
  display: flex;
  gap: var(--spacing-md);
}

.nav-button {
  padding: 0.5rem 1rem;
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  color: var(--color-text-primary);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.2s ease;
}

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

/* Mobile Menu Toggle */
.mobile-menu-toggle {
  display: none;
  position: fixed;
  top: calc(var(--topnav-height) + var(--spacing-md));
  left: var(--spacing-md);
  z-index: 1001;
  width: 40px;
  height: 40px;
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.mobile-menu-toggle:hover {
  background: var(--color-bg-tertiary);
}

.hamburger-icon {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-text-primary);
  margin: 0 auto;
  position: relative;
}

.hamburger-icon::before,
.hamburger-icon::after {
  content: '';
  position: absolute;
  width: 20px;
  height: 2px;
  background: var(--color-text-primary);
  left: 0;
}

.hamburger-icon::before {
  top: -6px;
}

.hamburger-icon::after {
  bottom: -6px;
}

/* =====================================================
   LAYOUT CONTAINER
   ===================================================== */

.layout-container {
  display: flex;
  margin-top: var(--topnav-height);
  min-height: calc(100vh - var(--topnav-height));
}

/* =====================================================
   SIDEBAR NAVIGATION
   ===================================================== */

.sidebar {
  position: fixed;
  top: var(--topnav-height);
  left: 0;
  width: var(--sidebar-width);
  height: calc(100vh - var(--topnav-height));
  background: var(--color-bg-secondary);
  border-right: 1px solid var(--color-border);
  overflow-y: auto;
  z-index: 100;
  transition: transform 0.3s ease;
}

.sidebar-content {
  padding: var(--spacing-xl) var(--spacing-lg);
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

.nav-section {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.nav-section-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  padding: var(--spacing-sm) var(--spacing-md);
  margin-bottom: var(--spacing-sm);
}

.nav-item {
  display: block;
  padding: 0.5rem var(--spacing-md);
  color: var(--color-text-secondary);
  text-decoration: none;
  border-radius: 6px;
  font-size: 0.9rem;
  transition: all 0.2s ease;
  border-left: 2px solid transparent;
}

.nav-item:hover {
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
}

.nav-item.active {
  background: var(--color-bg-tertiary);
  color: var(--color-accent-blue);
  border-left-color: var(--color-accent-blue);
  font-weight: 600;
}

.nav-item.sub-item {
  padding-left: var(--spacing-xl);
  font-size: 0.85rem;
}

/* =====================================================
   MAIN CONTENT AREA
   ===================================================== */

.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  padding: var(--spacing-2xl);
  max-width: calc(var(--content-max-width) + var(--sidebar-width));
}

.content-wrapper {
  max-width: var(--content-max-width);
}

/* =====================================================
   PAGE HEADER
   ===================================================== */

.page-header {
  margin-bottom: var(--spacing-2xl);
  padding-bottom: var(--spacing-xl);
  border-bottom: 1px solid var(--color-border);
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
}

.breadcrumb a {
  color: var(--color-accent-blue);
  text-decoration: none;
  transition: color 0.2s ease;
}

.breadcrumb a:hover {
  color: var(--color-text-primary);
  text-decoration: underline;
}

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

.page-title {
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

.page-description {
  font-size: 1.1rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: var(--spacing-lg);
}

.page-meta {
  display: flex;
  gap: var(--spacing-lg);
  flex-wrap: wrap;
}

.meta-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.meta-item svg {
  opacity: 0.7;
}

/* =====================================================
   ALERT BOXES
   ===================================================== */

.alert {
  display: flex;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  border-radius: 8px;
  margin-bottom: var(--spacing-xl);
  border-left: 4px solid;
}

.alert-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
  line-height: 1;
}

.alert-content {
  flex: 1;
}

.alert-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
}

.alert-list {
  margin-top: var(--spacing-md);
  padding-left: var(--spacing-lg);
  list-style: disc;
}

.alert-list li {
  margin-bottom: var(--spacing-sm);
}

.alert-danger {
  background: rgba(248, 81, 73, 0.1);
  border-color: var(--color-accent-red);
}

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

.alert-warning {
  background: rgba(210, 153, 34, 0.1);
  border-color: var(--color-accent-orange);
}

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

/* =====================================================
   INFO CARD
   ===================================================== */

.info-card {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  overflow: hidden;
  margin-bottom: var(--spacing-xl);
}

.info-card-header {
  padding: var(--spacing-lg);
  background: var(--color-bg-tertiary);
  border-bottom: 1px solid var(--color-border);
}

.info-card-header h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-accent-blue);
}

.info-card-body {
  padding: var(--spacing-lg);
}

.support-contact {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.support-image {
  max-width: 200px;
  border-radius: 8px;
  border: 1px solid var(--color-border);
}

.support-link {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: 0.75rem 1.5rem;
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  color: var(--color-accent-blue);
  text-decoration: none;
  font-weight: 600;
  transition: all 0.2s ease;
}

.support-link:hover {
  background: var(--color-bg-primary);
  border-color: var(--color-accent-blue);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* =====================================================
   CONTENT SECTIONS
   ===================================================== */

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

.section-title {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: var(--spacing-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  color: var(--color-text-primary);
  padding-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--color-border);
}

.title-icon {
  font-size: 1.5rem;
}

.section-intro {
  font-size: 1.05rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
}

/* =====================================================
   CHECKLIST
   ===================================================== */

.checklist {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.checklist-item {
  display: flex;
  gap: var(--spacing-lg);
  padding: var(--spacing-lg);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  transition: all 0.2s ease;
}

.checklist-item:hover {
  background: var(--color-bg-tertiary);
  border-color: var(--color-accent-blue);
}

.checklist-icon {
  font-size: 2rem;
  flex-shrink: 0;
  line-height: 1;
}

.checklist-content h4 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  color: var(--color-text-primary);
}

.checklist-content p {
  color: var(--color-text-secondary);
  font-size: 0.95rem;
}

.checklist-content a {
  color: var(--color-accent-blue);
  text-decoration: none;
}

.checklist-content a:hover {
  text-decoration: underline;
}

/* =====================================================
   DOWNLOAD SECTION
   ===================================================== */

.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
  margin-top: var(--spacing-lg);
}

.download-card {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  overflow: hidden;
  transition: all 0.2s ease;
}

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

.download-card-image {
  width: 100%;
  height: 200px;
  overflow: hidden;
  background: var(--color-bg-primary);
}

.download-card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.download-card:hover .download-card-image img {
  transform: scale(1.05);
}

.download-card-header {
  padding: var(--spacing-lg);
  background: var(--color-bg-tertiary);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.download-card-header h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-text-primary);
}

.download-badge {
  padding: 0.25rem 0.75rem;
  background: rgba(88, 166, 255, 0.2);
  border: 1px solid var(--color-accent-blue);
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-accent-blue);
}

.download-card-body {
  padding: var(--spacing-lg);
}

.download-card-body p {
  color: var(--color-text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

.download-card-footer {
  padding: var(--spacing-lg);
  padding-top: 0;
}

.download-button {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  width: 100%;
  padding: 0.75rem 1.5rem;
  background: var(--color-accent-blue);
  color: white;
  border: none;
  border-radius: 6px;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.2s ease;
}

.download-button:hover {
  background: #4a8dd8;
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

/* =====================================================
   INSTALLATION STEPS
   ===================================================== */

.step-container {
  margin-bottom: var(--spacing-xl);
  padding: var(--spacing-xl);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  scroll-margin-top: calc(var(--topnav-height) + var(--spacing-lg));
}

.step-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
  padding-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--color-border);
}

.step-number {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-blue);
  color: white;
  font-size: 1.5rem;
  font-weight: 700;
  border-radius: 50%;
  flex-shrink: 0;
}

.step-title {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--color-text-primary);
}

.step-content {
  padding-left: calc(48px + var(--spacing-lg));
}

.step-content p {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
  line-height: 1.7;
}

.step-note {
  padding: var(--spacing-md);
  background: rgba(88, 166, 255, 0.1);
  border-left: 3px solid var(--color-accent-blue);
  border-radius: 4px;
  margin-top: var(--spacing-lg);
  font-size: 0.95rem;
  color: var(--color-text-secondary);
}

.step-note strong {
  color: var(--color-accent-blue);
}

/* =====================================================
   CODE BLOCKS
   ===================================================== */

.code-block {
  margin: var(--spacing-lg) 0;
  background: var(--color-bg-primary);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  overflow: hidden;
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) var(--spacing-md);
  background: var(--color-bg-tertiary);
  border-bottom: 1px solid var(--color-border);
}

.code-lang {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--color-text-muted);
  letter-spacing: 0.05em;
}

.code-copy {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.25rem 0.5rem;
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  color: var(--color-text-secondary);
  font-size: 0.8rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.code-copy:hover {
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
}

.code-block pre {
  padding: var(--spacing-lg);
  margin: 0;
  overflow-x: auto;
}

.code-block code {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-accent-blue);
  line-height: 1.6;
}

code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  padding: 0.2em 0.4em;
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  color: var(--color-accent-blue);
}

/* =====================================================
   FOLDER TREE
   ===================================================== */

.folder-tree {
  padding: var(--spacing-lg);
  background: var(--color-bg-primary);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  margin: var(--spacing-lg) 0;
}

.tree-item {
  padding: 0.25rem 0;
  color: var(--color-text-secondary);
}

.tree-icon {
  margin-right: 0.5rem;
}

.tree-children {
  margin-left: 1.5rem;
  border-left: 1px solid var(--color-border);
  padding-left: var(--spacing-md);
}

.tree-note {
  color: var(--color-accent-green);
  font-style: italic;
  margin-left: var(--spacing-sm);
}

/* =====================================================
   FILE LIST
   ===================================================== */

.file-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  padding: var(--spacing-lg);
  background: var(--color-bg-primary);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  margin: var(--spacing-lg) 0;
}

.file-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm);
  background: var(--color-bg-secondary);
  border-radius: 4px;
}

.file-icon {
  font-size: 1.2rem;
}

.file-name {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-accent-blue);
}

/* =====================================================
   IMAGE GALLERY
   ===================================================== */

.image-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
  margin: var(--spacing-lg) 0;
}

.image-figure {
  margin: 0;
}

.tutorial-image {
  width: 100%;
  height: auto;
  border-radius: 8px;
  border: 1px solid var(--color-border);
  transition: all 0.2s ease;
}

.tutorial-image:hover {
  border-color: var(--color-accent-blue);
  box-shadow: var(--shadow-md);
}

figcaption {
  margin-top: var(--spacing-sm);
  font-size: 0.85rem;
  color: var(--color-text-muted);
  text-align: center;
  font-style: italic;
}

/* =====================================================
   TIPS GRID
   ===================================================== */

.tips-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
  margin-top: var(--spacing-lg);
}

.tip-card {
  padding: var(--spacing-lg);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  transition: all 0.2s ease;
}

.tip-card:hover {
  border-color: var(--color-accent-green);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.tip-icon {
  font-size: 2rem;
  margin-bottom: var(--spacing-md);
  display: block;
}

.tip-card h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-primary);
}

.tip-card p {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
}

/* =====================================================
   TOAST NOTIFICATION
   ===================================================== */

.toast {
  position: fixed;
  bottom: var(--spacing-xl);
  right: var(--spacing-xl);
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-accent-green);
  border-radius: 8px;
  box-shadow: var(--shadow-lg);
  transform: translateY(200%);
  transition: transform 0.3s ease;
  z-index: 2000;
  max-width: 400px;
  font-size: 0.95rem;
}

.toast.show {
  transform: translateY(0);
}

/* =====================================================
   RESPONSIVE DESIGN
   ===================================================== */

@media (max-width: 1024px) {
  :root {
    --sidebar-width: 240px;
  }
  
  .page-title {
    font-size: 2rem;
  }
}

@media (max-width: 768px) {
  .mobile-menu-toggle {
    display: block;
  }
  
  .sidebar {
    transform: translateX(-100%);
  }
  
  .sidebar.active {
    transform: translateX(0);
  }
  
  .main-content {
    margin-left: 0;
    padding: var(--spacing-lg);
  }
  
  .nav-title {
    display: none;
  }
  
  .page-title {
    font-size: 1.75rem;
  }
  
  .section-title {
    font-size: 1.5rem;
  }
  
  .step-content {
    padding-left: 0;
  }
  
  .download-grid,
  .tips-grid {
    grid-template-columns: 1fr;
  }
  
  .toast {
    bottom: var(--spacing-md);
    right: var(--spacing-md);
    left: var(--spacing-md);
    max-width: none;
  }
}

/* =====================================================
   ACCESSIBILITY
   ===================================================== */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Focus Styles */
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--color-accent-blue);
  outline-offset: 2px;
}

/* Selection */
::selection {
  background: rgba(88, 166, 255, 0.3);
  color: var(--color-text-primary);
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 12px;
  height: 12px;
}

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

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

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