/* ═══════════════════════════════════════════
   Docker Dojo — Design System & Styles
   ═══════════════════════════════════════════ */

:root {
  /* Colors */
  --bg-primary: #0a0e1a;
  --bg-secondary: #111827;
  --bg-card: #1a2035;
  --bg-card-hover: #1e2740;
  --bg-sidebar: #0d1220;
  --bg-terminal: #0c1017;

  --docker-blue: #2496ed;
  --docker-blue-light: #4fb3ff;
  --docker-blue-dark: #1a7ad4;
  --accent-cyan: #06d6a0;
  --accent-orange: #ff8c42;
  --accent-purple: #a78bfa;
  --accent-pink: #f472b6;
  --accent-red: #ef4444;
  --accent-yellow: #fbbf24;
  --accent-green: #34d399;

  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --border-color: rgba(148, 163, 184, 0.1);
  --border-glow: rgba(36, 150, 237, 0.3);

  /* Spacing */
  --sidebar-width: 280px;

  /* Typography */
  --font-sans: 'Inter', -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 30px rgba(36, 150, 237, 0.15);

  /* Transitions */
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  overflow: hidden;
  height: 100vh;
}

/* ═══════════════════════════════════════════
   Layout
   ═══════════════════════════════════════════ */

#app {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

/* ═══════════════════════════════════════════
   Sidebar
   ═══════════════════════════════════════════ */

#sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  transition: transform var(--transition);
  z-index: 100;
}

.sidebar-header {
  padding: 24px 20px 16px;
  border-bottom: 1px solid var(--border-color);
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
}

.logo-icon {
  font-size: 28px;
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

.logo-text {
  font-size: 20px;
  font-weight: 800;
  background: linear-gradient(135deg, var(--docker-blue), var(--accent-cyan));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -0.3px;
}

.progress-bar-container {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 10px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--docker-blue), var(--accent-cyan));
  border-radius: 10px;
  transition: width 0.5s ease;
}

.progress-label {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  color: var(--text-muted);
  font-weight: 500;
}

.nav-list {
  list-style: none;
  flex: 1;
  overflow-y: auto;
  padding: 12px 10px;
}

.nav-item {
  margin-bottom: 2px;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border-radius: 10px;
  cursor: pointer;
  color: var(--text-secondary);
  font-size: 13.5px;
  font-weight: 500;
  transition: all var(--transition);
  user-select: none;
  position: relative;
}

.nav-link:hover {
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-primary);
}

.nav-link.active {
  background: rgba(36, 150, 237, 0.12);
  color: var(--docker-blue-light);
  font-weight: 600;
}

.nav-link.active::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 60%;
  background: var(--docker-blue);
  border-radius: 0 4px 4px 0;
}

.nav-link.completed {
  color: var(--accent-green);
}

.nav-icon {
  font-size: 16px;
  width: 24px;
  text-align: center;
  flex-shrink: 0;
}

.nav-check {
  margin-left: auto;
  font-size: 14px;
  opacity: 0;
  transition: opacity var(--transition);
}

.nav-link.completed .nav-check {
  opacity: 1;
}

.nav-section-title {
  padding: 16px 14px 6px;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-muted);
  font-weight: 700;
}

.sidebar-footer {
  padding: 12px 14px;
  border-top: 1px solid var(--border-color);
}

.btn-reset {
  width: 100%;
  padding: 8px;
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  border-radius: 8px;
  font-family: var(--font-sans);
  font-size: 12px;
  cursor: pointer;
  transition: all var(--transition);
}

.btn-reset:hover {
  border-color: var(--accent-red);
  color: var(--accent-red);
  background: rgba(239, 68, 68, 0.08);
}

/* ═══════════════════════════════════════════
   Main Content
   ═══════════════════════════════════════════ */

#mainContent {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.topbar {
  display: none;
  align-items: center;
  gap: 12px;
  padding: 12px 20px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
}

.btn-menu {
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 22px;
  cursor: pointer;
  padding: 4px;
}

.topbar-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
}

.lesson-container {
  flex: 1;
  overflow-y: auto;
  padding: 40px;
  scroll-behavior: smooth;
}

.lesson-nav {
  display: flex;
  justify-content: space-between;
  padding: 16px 40px;
  border-top: 1px solid var(--border-color);
  background: var(--bg-secondary);
}

.btn {
  padding: 10px 24px;
  border-radius: 10px;
  border: none;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  display: flex;
  align-items: center;
  gap: 6px;
}

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

.btn-prev:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
}

.btn-next {
  background: linear-gradient(135deg, var(--docker-blue), var(--docker-blue-dark));
  color: white;
  box-shadow: 0 4px 15px rgba(36, 150, 237, 0.3);
}

.btn-next:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(36, 150, 237, 0.4);
}

.btn:disabled {
  opacity: 0.3;
  cursor: not-allowed;
  transform: none !important;
}

/* ═══════════════════════════════════════════
   Lesson Content Styles
   ═══════════════════════════════════════════ */

.lesson {
  max-width: 860px;
  margin: 0 auto;
  animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.lesson-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  background: rgba(36, 150, 237, 0.1);
  border: 1px solid rgba(36, 150, 237, 0.2);
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  color: var(--docker-blue-light);
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.lesson h1 {
  font-size: 36px;
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 12px;
  letter-spacing: -0.5px;
}

.lesson h1 .emoji {
  margin-right: 10px;
}

.lesson-subtitle {
  font-size: 17px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 36px;
}

.lesson h2 {
  font-size: 22px;
  font-weight: 700;
  margin: 36px 0 16px;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
}

.lesson h3 {
  font-size: 17px;
  font-weight: 700;
  margin: 24px 0 10px;
  color: var(--text-primary);
}

.lesson p {
  margin-bottom: 16px;
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.8;
}

.lesson ul, .lesson ol {
  margin: 0 0 16px 20px;
  color: var(--text-secondary);
}

.lesson li {
  margin-bottom: 8px;
  font-size: 15px;
  line-height: 1.7;
}

/* ═══════════════════════════════════════════
   Visual Cards & Boxes
   ═══════════════════════════════════════════ */

.visual-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 28px;
  margin: 24px 0;
  position: relative;
  overflow: hidden;
}

.visual-box::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--docker-blue), var(--accent-cyan), var(--accent-purple));
}

.visual-box.green::before {
  background: linear-gradient(90deg, var(--accent-green), var(--accent-cyan));
}

.visual-box.orange::before {
  background: linear-gradient(90deg, var(--accent-orange), var(--accent-yellow));
}

.visual-box.purple::before {
  background: linear-gradient(90deg, var(--accent-purple), var(--accent-pink));
}

.analogy-box {
  background: linear-gradient(135deg, rgba(36, 150, 237, 0.08), rgba(6, 214, 160, 0.05));
  border: 1px solid rgba(36, 150, 237, 0.15);
  border-radius: 14px;
  padding: 24px;
  margin: 24px 0;
  position: relative;
}

.analogy-box .analogy-emoji {
  font-size: 36px;
  margin-bottom: 12px;
  display: block;
}

.analogy-box .analogy-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--docker-blue-light);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 8px;
}

.analogy-box p {
  color: var(--text-primary);
  font-size: 15px;
}

/* ═══════════════════════════════════════════
   Terminal / Code Blocks
   ═══════════════════════════════════════════ */

.terminal {
  background: var(--bg-terminal);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 12px;
  margin: 20px 0;
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.terminal-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  background: rgba(255, 255, 255, 0.03);
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.terminal-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.terminal-dot.red { background: #ff5f57; }
.terminal-dot.yellow { background: #febc2e; }
.terminal-dot.green { background: #28c840; }

.terminal-title {
  margin-left: 8px;
  font-size: 12px;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.terminal-body {
  padding: 18px 20px;
  overflow-x: auto;
}

.terminal-body code {
  font-family: var(--font-mono);
  font-size: 13.5px;
  line-height: 1.8;
  color: #e2e8f0;
  white-space: pre;
  display: block;
}

.terminal-body .comment { color: #64748b; }
.terminal-body .command { color: var(--accent-cyan); }
.terminal-body .flag { color: var(--accent-orange); }
.terminal-body .string { color: var(--accent-yellow); }
.terminal-body .output { color: var(--text-muted); }
.terminal-body .keyword { color: var(--accent-purple); }
.terminal-body .success { color: var(--accent-green); }

.copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  padding: 4px 10px;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 6px;
  color: var(--text-muted);
  font-size: 11px;
  font-family: var(--font-mono);
  cursor: pointer;
  transition: all var(--transition);
}

.copy-btn:hover {
  background: rgba(255,255,255,0.12);
  color: var(--text-primary);
}

.inline-code {
  font-family: var(--font-mono);
  font-size: 13px;
  background: rgba(36, 150, 237, 0.12);
  color: var(--docker-blue-light);
  padding: 2px 8px;
  border-radius: 5px;
  border: 1px solid rgba(36, 150, 237, 0.15);
}

/* ═══════════════════════════════════════════
   Diagrams — ASCII-style Visuals
   ═══════════════════════════════════════════ */

.diagram {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 30px;
  margin: 24px 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  overflow-x: auto;
}

.diagram-title {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.diagram-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: center;
}

.diagram-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 16px 20px;
  border-radius: 12px;
  font-size: 13px;
  font-weight: 600;
  min-width: 100px;
  text-align: center;
  transition: transform 0.3s ease;
  position: relative;
}

.diagram-box:hover {
  transform: translateY(-3px);
}

.diagram-box.blue {
  background: rgba(36, 150, 237, 0.15);
  border: 1px solid rgba(36, 150, 237, 0.3);
  color: var(--docker-blue-light);
}

.diagram-box.green {
  background: rgba(6, 214, 160, 0.12);
  border: 1px solid rgba(6, 214, 160, 0.25);
  color: var(--accent-green);
}

.diagram-box.orange {
  background: rgba(255, 140, 66, 0.12);
  border: 1px solid rgba(255, 140, 66, 0.25);
  color: var(--accent-orange);
}

.diagram-box.purple {
  background: rgba(167, 139, 250, 0.12);
  border: 1px solid rgba(167, 139, 250, 0.25);
  color: var(--accent-purple);
}

.diagram-box.pink {
  background: rgba(244, 114, 182, 0.12);
  border: 1px solid rgba(244, 114, 182, 0.25);
  color: var(--accent-pink);
}

.diagram-box .box-icon {
  font-size: 24px;
}

.diagram-arrow {
  font-size: 20px;
  color: var(--text-muted);
}

.diagram-arrow.down {
  transform: rotate(90deg);
}

/* ═══════════════════════════════════════════
   Comparison Table
   ═══════════════════════════════════════════ */

.compare-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  margin: 20px 0;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--border-color);
}

.compare-table th {
  background: rgba(36, 150, 237, 0.1);
  color: var(--docker-blue-light);
  padding: 14px 18px;
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  text-align: left;
}

.compare-table td {
  padding: 12px 18px;
  font-size: 14px;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-card);
}

.compare-table tr:last-child td {
  border-bottom: none;
}

.compare-table tr:hover td {
  background: var(--bg-card-hover);
}

/* ═══════════════════════════════════════════
   Interactive Quiz
   ═══════════════════════════════════════════ */

.quiz {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 28px;
  margin: 28px 0;
}

.quiz-title {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.quiz-question {
  color: var(--text-secondary);
  font-size: 15px;
  margin-bottom: 16px;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.quiz-option {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-radius: 10px;
  border: 1px solid var(--border-color);
  cursor: pointer;
  transition: all var(--transition);
  font-size: 14px;
  color: var(--text-secondary);
}

.quiz-option:hover {
  border-color: var(--docker-blue);
  background: rgba(36, 150, 237, 0.06);
  color: var(--text-primary);
}

.quiz-option.selected {
  border-color: var(--docker-blue);
  background: rgba(36, 150, 237, 0.1);
  color: var(--text-primary);
}

.quiz-option.correct {
  border-color: var(--accent-green);
  background: rgba(6, 214, 160, 0.1);
  color: var(--accent-green);
}

.quiz-option.wrong {
  border-color: var(--accent-red);
  background: rgba(239, 68, 68, 0.1);
  color: var(--accent-red);
}

.quiz-option .option-letter {
  width: 26px;
  height: 26px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 7px;
  background: rgba(255, 255, 255, 0.04);
  font-weight: 700;
  font-size: 12px;
  flex-shrink: 0;
}

.quiz-feedback {
  margin-top: 14px;
  padding: 12px 16px;
  border-radius: 10px;
  font-size: 14px;
  display: none;
}

.quiz-feedback.show { display: block; }

.quiz-feedback.correct {
  background: rgba(6, 214, 160, 0.08);
  border: 1px solid rgba(6, 214, 160, 0.2);
  color: var(--accent-green);
}

.quiz-feedback.wrong {
  background: rgba(239, 68, 68, 0.08);
  border: 1px solid rgba(239, 68, 68, 0.2);
  color: var(--accent-red);
}

/* ═══════════════════════════════════════════
   Tip / Warning / Info Boxes
   ═══════════════════════════════════════════ */

.callout {
  padding: 18px 20px;
  border-radius: 12px;
  margin: 20px 0;
  font-size: 14px;
  line-height: 1.7;
  display: flex;
  gap: 12px;
}

.callout-icon {
  font-size: 20px;
  flex-shrink: 0;
  margin-top: 2px;
}

.callout.tip {
  background: rgba(6, 214, 160, 0.06);
  border: 1px solid rgba(6, 214, 160, 0.15);
  color: var(--accent-green);
}

.callout.warn {
  background: rgba(251, 191, 36, 0.06);
  border: 1px solid rgba(251, 191, 36, 0.15);
  color: var(--accent-yellow);
}

.callout.info {
  background: rgba(36, 150, 237, 0.06);
  border: 1px solid rgba(36, 150, 237, 0.15);
  color: var(--docker-blue-light);
}

/* ═══════════════════════════════════════════
   Step Cards (Numbered Steps)
   ═══════════════════════════════════════════ */

.steps {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin: 20px 0;
}

.step-card {
  display: flex;
  gap: 16px;
  padding: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  transition: all var(--transition);
}

.step-card:hover {
  border-color: var(--border-glow);
  box-shadow: var(--shadow-glow);
}

.step-number {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--docker-blue), var(--docker-blue-dark));
  color: white;
  font-weight: 800;
  font-size: 14px;
  flex-shrink: 0;
}

.step-content h4 {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 4px;
  color: var(--text-primary);
}

.step-content p {
  font-size: 14px;
  color: var(--text-secondary);
  margin: 0;
}

/* ═══════════════════════════════════════════
   Welcome / Completion Cards
   ═══════════════════════════════════════════ */

.hero-card {
  text-align: center;
  padding: 60px 40px;
  background: linear-gradient(135deg, rgba(36, 150, 237, 0.08), rgba(6, 214, 160, 0.04), rgba(167, 139, 250, 0.04));
  border: 1px solid rgba(36, 150, 237, 0.15);
  border-radius: 20px;
  margin-bottom: 36px;
}

.hero-whale {
  font-size: 72px;
  display: block;
  margin-bottom: 16px;
  animation: float 3s ease-in-out infinite;
}

.hero-card h1 {
  font-size: 42px;
  font-weight: 900;
  margin-bottom: 12px;
  background: linear-gradient(135deg, var(--docker-blue-light), var(--accent-cyan));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin: 24px 0;
}

.feature-item {
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  text-align: center;
  transition: all var(--transition);
}

.feature-item:hover {
  border-color: var(--border-glow);
  transform: translateY(-3px);
  box-shadow: var(--shadow-glow);
}

.feature-item .fi-icon {
  font-size: 32px;
  display: block;
  margin-bottom: 12px;
}

.feature-item .fi-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.feature-item .fi-desc {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ═══════════════════════════════════════════
   Interactive Visual: Container Layers
   ═══════════════════════════════════════════ */

.layer-stack {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin: 20px auto;
  max-width: 420px;
}

.layer {
  padding: 14px 20px;
  border-radius: 10px;
  font-size: 13px;
  font-weight: 600;
  text-align: center;
  transition: all 0.3s ease;
  cursor: default;
  position: relative;
  overflow: hidden;
}

.layer:hover {
  transform: scale(1.03);
  z-index: 1;
}

.layer.rw {
  background: rgba(6, 214, 160, 0.15);
  border: 1px dashed rgba(6, 214, 160, 0.4);
  color: var(--accent-green);
}

.layer.ro {
  background: rgba(36, 150, 237, 0.1);
  border: 1px solid rgba(36, 150, 237, 0.2);
  color: var(--docker-blue-light);
}

.layer-label {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 10px;
  opacity: 0.6;
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* ═══════════════════════════════════════════
   Cheat Sheet Grid
   ═══════════════════════════════════════════ */

.cheat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin: 20px 0;
}

.cheat-item {
  padding: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  transition: all var(--transition);
}

.cheat-item:hover {
  border-color: var(--border-glow);
}

.cheat-cmd {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent-cyan);
  margin-bottom: 6px;
  font-weight: 600;
}

.cheat-desc {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ═══════════════════════════════════════════
   Animated Container Demo
   ═══════════════════════════════════════════ */

.container-demo {
  position: relative;
  padding: 30px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  margin: 24px 0;
  min-height: 200px;
  overflow: hidden;
}

.container-demo .demo-label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.mini-container {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 600;
  margin: 4px;
  animation: slideIn 0.5s ease forwards;
  opacity: 0;
}

.mini-container:nth-child(2) { animation-delay: 0.1s; }
.mini-container:nth-child(3) { animation-delay: 0.2s; }
.mini-container:nth-child(4) { animation-delay: 0.3s; }
.mini-container:nth-child(5) { animation-delay: 0.4s; }

@keyframes slideIn {
  from { opacity: 0; transform: translateX(-20px); }
  to { opacity: 1; transform: translateX(0); }
}

.mini-container.running {
  background: rgba(6, 214, 160, 0.12);
  border: 1px solid rgba(6, 214, 160, 0.25);
  color: var(--accent-green);
}

.mini-container.stopped {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.2);
  color: var(--accent-red);
}

.mini-container .status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
}

.mini-container.running .status-dot {
  background: var(--accent-green);
  box-shadow: 0 0 8px var(--accent-green);
  animation: pulse 2s ease-in-out infinite;
}

.mini-container.stopped .status-dot {
  background: var(--accent-red);
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

/* ═══════════════════════════════════════════
   Responsive
   ═══════════════════════════════════════════ */

@media (max-width: 900px) {
  #sidebar {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    transform: translateX(-100%);
    box-shadow: var(--shadow-lg);
  }

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

  .topbar {
    display: flex;
  }

  .lesson-container {
    padding: 24px 20px;
  }

  .lesson-nav {
    padding: 12px 20px;
  }

  .hero-card {
    padding: 40px 20px;
  }

  .hero-card h1 {
    font-size: 28px;
  }

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

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

/* Overlay for mobile sidebar */
.sidebar-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.6);
  z-index: 99;
  backdrop-filter: blur(4px);
}

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

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.08);
  border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.15);
}