/* Codelab Web App CSS - Premium Design System */
@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:ital,wght@0,400;0,700;1,400&family=Outfit:wght@300;400;500;600;700;800&family=Plus+Jakarta+Sans:ital,wght@0,400;0,500;0,600;0,700;1,400&display=swap');

:root {
  /* Common variables */
  --font-heading: 'Outfit', sans-serif;
  --font-body: 'Plus Jakarta Sans', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  --sidebar-width: 320px;
  --header-height: 72px;
  --border-radius-sm: 8px;
  --border-radius-md: 12px;
  --border-radius-lg: 20px;
  --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 8px 30px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 20px 40px rgba(0, 0, 0, 0.12);
  --gradient-primary: linear-gradient(135deg, #2563eb, #7c3aed);
  --gradient-accent: linear-gradient(135deg, #3b82f6, #8b5cf6, #ec4899);

  /* Light Theme Variables */
  --bg-app: #f8fafc;
  --bg-sidebar: #ffffff;
  --bg-card: #ffffff;
  --bg-header: rgba(255, 255, 255, 0.8);
  --bg-code: #0f172a; /* Keep code block dark for readability */
  --bg-code-header: #1e293b;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --border-color: #e2e8f0;
  --accent-color: #4f46e5;
  --accent-light: rgba(79, 70, 229, 0.1);
  --success-color: #10b981;
  --success-bg: rgba(16, 185, 129, 0.1);
  --warning-color: #f59e0b;
  --warning-bg: rgba(245, 158, 11, 0.1);
}

[data-theme="dark"] {
  /* Dark Theme Variables */
  --bg-app: #090d16;
  --bg-sidebar: #0f1524;
  --bg-card: #151d30;
  --bg-header: rgba(15, 21, 36, 0.8);
  --bg-code: #0b0f19;
  --bg-code-header: #131b2d;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border-color: #1e293b;
  --accent-color: #818cf8;
  --accent-light: rgba(129, 140, 248, 0.15);
  --success-color: #34d399;
  --success-bg: rgba(52, 211, 153, 0.15);
  --warning-color: #fbbf24;
  --warning-bg: rgba(251, 191, 36, 0.15);
  --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 12px 36px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 24px 48px rgba(0, 0, 0, 0.5);
  --gradient-primary: linear-gradient(135deg, #6366f1, #a855f7);
}

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

body {
  font-family: var(--font-body);
  background-color: var(--bg-app);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  transition: background-color 0.4s ease, color 0.4s ease;
  line-height: 1.6;
}

/* Custom Scrollbars */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* App Shell Layout */
#header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background-color: var(--bg-header);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  z-index: 100;
  transition: var(--transition-smooth);
}

.header-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.header-logo-container {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: var(--gradient-primary);
  border-radius: var(--border-radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  font-family: var(--font-heading);
}

.header-title-wrapper {
  display: flex;
  flex-direction: column;
}

.header-tag {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-color);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 2px;
}

.header-title {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-primary);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

/* Progress indicator in Header */
.progress-container {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.25rem;
}

.progress-info {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.progress-bar-bg {
  width: 160px;
  height: 6px;
  background: var(--border-color);
  border-radius: 3px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: var(--gradient-primary);
  border-radius: 3px;
  transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Theme Toggle Button */
.btn-theme-toggle {
  background: none;
  border: 1px solid var(--border-color);
  width: 40px;
  height: 40px;
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: var(--transition-smooth);
}

.btn-theme-toggle:hover {
  background-color: var(--accent-light);
  border-color: var(--accent-color);
  color: var(--accent-color);
}

.btn-theme-toggle svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
}

/* Main Container: Sidebar + Content */
.main-wrapper {
  display: flex;
  margin-top: var(--header-height);
  min-height: calc(100vh - var(--header-height));
  position: relative;
}

/* Hamburger Menu (Mobile Navigation Toggle) */
.mobile-nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
}

/* Sidebar Styling */
#sidebar {
  width: var(--sidebar-width);
  background-color: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  position: fixed;
  top: var(--header-height);
  bottom: 0;
  left: 0;
  overflow-y: auto;
  z-index: 90;
  transition: var(--transition-smooth);
  display: flex;
  flex-direction: column;
}

.sidebar-header {
  padding: 1.5rem;
  border-bottom: 1px solid var(--border-color);
}

.sidebar-title {
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-secondary);
}

.sidebar-steps-list {
  list-style: none;
  padding: 1rem 0;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.step-item {
  display: flex;
  align-items: center;
  padding: 0.85rem 1.5rem;
  cursor: pointer;
  transition: var(--transition-smooth);
  border-left: 4px solid transparent;
  gap: 1rem;
  position: relative;
}

.step-item:hover {
  background-color: var(--accent-light);
}

.step-item.active {
  background-color: var(--accent-light);
  border-left-color: var(--accent-color);
  font-weight: 600;
}

.step-status-icon {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 2px solid var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-muted);
  transition: var(--transition-smooth);
  flex-shrink: 0;
}

.step-item.active .step-status-icon {
  border-color: var(--accent-color);
  color: var(--accent-color);
  background: var(--bg-sidebar);
}

.step-item.completed .step-status-icon {
  background-color: var(--success-color);
  border-color: var(--success-color);
  color: #ffffff;
}

.step-item.completed .step-status-icon::before {
  content: "✓";
  font-size: 0.8rem;
}

.step-info {
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.step-title {
  font-size: 0.9rem;
  color: var(--text-primary);
  white-space: nowrap;
  text-overflow: ellipsis;
  overflow: hidden;
  transition: var(--transition-smooth);
}

.step-item.active .step-title {
  color: var(--text-primary);
}

.step-duration {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 2px;
}

/* Content Panel Container */
#content-panel {
  flex: 1;
  margin-left: var(--sidebar-width);
  padding: 3rem 4rem 8rem 4rem;
  overflow-y: auto;
  transition: var(--transition-smooth);
  display: flex;
  justify-content: center;
}

#sidebar.hidden + #content-panel {
  margin-left: 0;
}


.content-inner {
  max-width: 800px;
  width: 100%;
  animation: fadeIn 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Markdown/Codelab Content Styling */
.codelab-step-header {
  margin-bottom: 2.5rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1.5rem;
}

.codelab-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.75rem;
}

.badge {
  padding: 0.25rem 0.75rem;
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 600;
}

.badge-time {
  background-color: var(--accent-light);
  color: var(--accent-color);
}

.badge-step {
  background-color: var(--border-color);
  color: var(--text-secondary);
}

.codelab-step-title {
  font-family: var(--font-heading);
  font-size: 2.25rem;
  font-weight: 800;
  line-height: 1.2;
  color: var(--text-primary);
}

.codelab-step-body {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.codelab-step-body p {
  margin-bottom: 1.5rem;
}

.codelab-step-body h2 {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  margin: 2.5rem 0 1rem 0;
  color: var(--text-primary);
}

.codelab-step-body h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 600;
  margin: 2rem 0 1rem 0;
  color: var(--text-primary);
}

/* Alert Boxes in Codelab Body */
.alert {
  padding: 1.25rem 1.5rem;
  border-radius: var(--border-radius-md);
  margin: 1.5rem 0;
  border-left: 4px solid;
  display: flex;
  gap: 1rem;
}

.alert-icon {
  font-size: 1.25rem;
  flex-shrink: 0;
  line-height: 1;
}

.alert-content {
  flex: 1;
}

.alert-content p:last-child {
  margin-bottom: 0;
}

.alert-info {
  background-color: var(--accent-light);
  border-color: var(--accent-color);
  color: var(--text-primary);
}

.alert-success {
  background-color: var(--success-bg);
  border-color: var(--success-color);
  color: var(--text-primary);
}

.alert-warning {
  background-color: var(--warning-bg);
  border-color: var(--warning-color);
  color: var(--text-primary);
}

/* Inline Code and Code Blocks */
code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background-color: var(--border-color);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  color: var(--accent-color);
}

pre {
  margin: 1.5rem 0;
  background-color: var(--bg-code);
  border-radius: var(--border-radius-md);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

pre code {
  display: block;
  padding: 1.25rem 1.5rem;
  overflow-x: auto;
  background-color: transparent;
  color: #f8fafc;
  line-height: 1.5;
  font-size: 0.9rem;
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.5rem 1.5rem;
  background-color: var(--bg-code-header);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 0.8rem;
  color: #94a3b8;
}

.code-lang {
  text-transform: uppercase;
  font-weight: 600;
  letter-spacing: 0.5px;
}

.btn-copy {
  background: rgba(255, 255, 255, 0.1);
  border: none;
  border-radius: 4px;
  color: #f8fafc;
  padding: 0.25rem 0.75rem;
  font-size: 0.75rem;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.btn-copy:hover {
  background: rgba(255, 255, 255, 0.2);
}

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

/* Checklists */
.checklist-item {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
  cursor: pointer;
}

.checklist-checkbox {
  margin-top: 0.25rem;
  width: 1.2rem;
  height: 1.2rem;
  accent-color: var(--accent-color);
  cursor: pointer;
}

.checklist-text {
  font-size: 1rem;
}

.checklist-item.checked .checklist-text {
  text-decoration: line-through;
  color: var(--text-muted);
}

/* Footer Control Bar */
#footer-controls {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 72px;
  background-color: var(--bg-sidebar);
  border-top: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 4rem;
  z-index: 95;
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.02);
}

.control-btn {
  padding: 0.75rem 1.5rem;
  border-radius: var(--border-radius-sm);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: var(--transition-smooth);
  border: 1px solid transparent;
}

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

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

.btn-prev:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-next {
  background: var(--gradient-primary);
  color: white;
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.25);
}

.btn-next:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(79, 70, 229, 0.35);
}

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

/* Completion/Celebration View */
.celebration-view {
  text-align: center;
  padding: 2rem 0;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.celebration-icon {
  font-size: 4rem;
  margin-bottom: 1.5rem;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.celebration-title {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 800;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 1rem;
}

.celebration-text {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 500px;
  margin-bottom: 2rem;
  line-height: 1.7;
}

.btn-share {
  background: var(--gradient-accent);
  color: white;
  padding: 0.85rem 2rem;
  border-radius: var(--border-radius-sm);
  border: none;
  font-family: var(--font-heading);
  font-weight: 700;
  cursor: pointer;
  box-shadow: var(--shadow-md);
  transition: var(--transition-smooth);
}

.btn-share:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* Confetti Canvas Overlay */
#confetti-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 1000;
}

/* Media Queries for Responsiveness */
@media (max-width: 992px) {
  :root {
    --sidebar-width: 280px;
  }
  #content-panel {
    padding: 2.5rem 2.5rem 7rem 2.5rem;
  }
  #footer-controls {
    padding: 0 2.5rem;
  }
}

@media (max-width: 768px) {
  /* Sidebar Mobile Layout Overlay */
  #sidebar {
    transform: translateX(-100%);
    width: 280px;
    box-shadow: var(--shadow-lg);
  }

  #sidebar.open {
    transform: translateX(0);
  }

  #content-panel {
    margin-left: 0;
    padding: 2rem 1.5rem 7rem 1.5rem;
  }

  #footer-controls {
    padding: 0 1.5rem;
    margin-left: 0;
    left: 0;
  }

  .mobile-nav-toggle {
    display: block;
    margin-right: 0.5rem;
  }

  .header-logo-container span {
    font-size: 1.1rem;
  }

  .progress-container {
    display: none; /* Hide progress bar on small devices header */
  }

  /* Overlay cover when sidebar is open */
  .sidebar-overlay {
    display: none;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.4);
    z-index: 85;
    backdrop-filter: blur(4px);
  }

  .sidebar-overlay.active {
    display: block;
  }
}

/* Blackstar Codelabs Homepage styling */
.hidden {
  display: none !important;
}

.home-view {
  margin-top: var(--header-height);
  min-height: calc(100vh - var(--header-height));
  padding: 3rem 2rem 5rem 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  width: 100%;
  box-sizing: border-box;
}

.home-hero {
  text-align: center;
  margin-bottom: 3.5rem;
  max-width: 700px;
}

.home-hero h1 {
  font-family: var(--font-heading);
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.2;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 1rem;
  letter-spacing: -0.5px;
}

.home-hero p {
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.search-filter-wrapper {
  width: 100%;
  max-width: 800px;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-bottom: 3rem;
  background-color: var(--bg-sidebar);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  box-sizing: border-box;
}

.search-input-container {
  position: relative;
  width: 100%;
}

.search-input {
  width: 100%;
  background-color: var(--bg-app);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-sm);
  padding: 0.85rem 1rem 0.85rem 2.75rem;
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--text-primary);
  transition: var(--transition-smooth);
  box-sizing: border-box;
}

.search-input:focus {
  outline: none;
  border-color: var(--accent-color);
  box-shadow: 0 0 0 3px var(--accent-light);
}

.search-icon-svg {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  width: 18px;
  height: 18px;
  fill: var(--text-muted);
  pointer-events: none;
}

.filter-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

.filter-label {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-secondary);
  margin-right: 0.5rem;
}

.filter-pill {
  background-color: var(--bg-app);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 0.4rem 1rem;
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.filter-pill:hover {
  background-color: var(--accent-light);
  color: var(--accent-color);
  border-color: var(--accent-color);
}

.filter-pill.active {
  background: var(--gradient-primary);
  color: white;
  border-color: transparent;
}

.codelabs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 2rem;
  width: 100%;
}

.no-results {
  grid-column: 1 / -1;
  text-align: center;
  padding: 4rem 2rem;
  color: var(--text-secondary);
}

.no-results-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.codelab-card {
  background-color: var(--bg-sidebar);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  height: 100%;
  cursor: pointer;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s ease, border-color 0.3s ease;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
  box-sizing: border-box;
}

.codelab-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--gradient-primary);
  opacity: 0;
  transition: var(--transition-smooth);
}

.codelab-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent-color);
}

.codelab-card:hover::before {
  opacity: 1;
}

.card-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 1.25rem;
  width: 100%;
}

.card-icon {
  width: 44px;
  height: 44px;
  background-color: var(--accent-light);
  border-radius: var(--border-radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}

.card-badge {
  background-color: var(--border-color);
  color: var(--text-secondary);
  padding: 0.25rem 0.75rem;
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.codelab-card h2 {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 1.5rem;
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 1rem;
  margin-top: auto;
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 600;
  width: 100%;
}

.card-duration {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.card-author {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 150px;
}