@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;700&display=swap');

:root {
  --bg-primary: #0a0e17;
  --bg-secondary: #111827;
  --bg-tertiary: #1a2332;
  --bg-code: #0d1117;
  --text-primary: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent: #00d4aa;
  --accent-dim: #00a88a;
  --accent-glow: rgba(0, 212, 170, 0.15);
  --danger: #ef4444;
  --warning: #f59e0b;
  --success: #22c55e;
  --info: #3b82f6;
  --border: #1e293b;
  --border-light: #334155;
  --sidebar-width: 300px;
  --header-height: 60px;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Consolas', 'Courier New', monospace;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.75;
  font-size: 15px;
  overflow: hidden;
  height: 100vh;
}

* {
  scrollbar-width: thin;
  scrollbar-color: var(--border-light) var(--bg-primary);
}

::-webkit-scrollbar {
  width: 6px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--border-light);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

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

/* ========== SIDEBAR ========== */
#sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  background: var(--bg-secondary);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: transform 0.3s ease;
  z-index: 100;
}

.sidebar-header {
  padding: 20px;
  border-bottom: 1px solid var(--border);
  text-align: center;
}

.sidebar-header h1 {
  font-size: 16px;
  color: var(--accent);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.sidebar-header .subtitle {
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 1px;
}

.sidebar-progress {
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
}

.progress-bar-container {
  background: var(--bg-primary);
  border-radius: 4px;
  height: 6px;
  overflow: hidden;
  margin-bottom: 6px;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent-dim));
  border-radius: 4px;
  transition: width 0.5s ease;
  width: 0%;
}

.progress-text {
  font-size: 11px;
  color: var(--text-muted);
  text-align: center;
}

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 10px 0;
}

.nav-section-title {
  padding: 8px 20px;
  font-size: 10px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 2px;
  font-weight: 700;
}

.nav-item {
  display: flex;
  align-items: center;
  padding: 10px 20px;
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease;
  border-left: 3px solid transparent;
  gap: 10px;
}

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

.nav-item.active {
  background: var(--accent-glow);
  border-left-color: var(--accent);
  color: var(--accent);
}

.nav-item.completed .nav-icon {
  color: var(--success);
}

.nav-icon {
  font-size: 15px;
  width: 20px;
  text-align: center;
  flex-shrink: 0;
}

.nav-label {
  font-size: 14px;
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-check {
  width: 16px;
  height: 16px;
  border: 1px solid var(--border-light);
  border-radius: 3px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  transition: border-color 0.2s;
}

.nav-item.completed .nav-check {
  background: var(--success);
  border-color: var(--success);
  color: white;
}

.sidebar-footer {
  padding: 15px 20px;
  border-top: 1px solid var(--border);
  text-align: center;
}

.sidebar-footer button {
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 8px 16px;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-size: 11px;
  transition: border-color 0.2s, color 0.2s;
  width: 100%;
}

.sidebar-footer button:hover {
  border-color: var(--accent);
  color: var(--accent);
}

  .sidebar-close-mobile {
  display: none;
  position: absolute;
  top: 10px;
  right: 10px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  color: var(--text-muted);
  width: 32px;
  height: 32px;
  border-radius: 50%;
  font-size: 22px;
  cursor: pointer;
}

@media (max-width: 768px) {
  .sidebar-close-mobile {
    display: block;
  }
}

/* ========== MAIN CONTENT ========== */
#main {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  position: relative;
}

#topbar {
  height: var(--header-height);
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 24px;
  gap: 16px;
  flex-shrink: 0;
  position: relative;
}

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

.breadcrumb {
  font-size: 14px;
  color: var(--text-muted);
}

.breadcrumb span {
  color: var(--accent);
}

.topbar-actions {
  margin-left: auto;
  display: flex;
  gap: 10px;
  align-items: center;
}

.topbar-btn {
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 6px 14px;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-size: 12px;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 6px;
}

.topbar-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

#main-content {
  flex: 1;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

#scroll-fade {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 80px;
  background: linear-gradient(to bottom, transparent, var(--bg-primary));
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: 5;
}
#scroll-fade.visible {
  opacity: 1;
}

#content {
  padding: 36px 56px 60px;
  max-width: 860px;
  width: 100%;
  margin: 0 auto;
}

/* ========== CONTENT STYLES ========== */
.chapter-title {
  font-size: 28px;
  color: var(--accent);
  margin-bottom: 6px;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.chapter-subtitle {
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.chapter-intro {
  color: var(--text-secondary);
  line-height: 1.75;
  margin: 12px 0 28px;
  font-size: 14.5px;
}

.section {
  margin-bottom: 32px;
}

.section-title {
  font-size: 17px;
  color: var(--text-primary);
  margin-bottom: 14px;
  margin-top: 28px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.section-title .icon {
  color: var(--accent);
}

.section-title .number {
  background: var(--accent);
  color: var(--bg-primary);
  padding: 2px 8px;
  border-radius: 3px;
  font-size: 12px;
  font-weight: 700;
}

p, li {
  margin-bottom: 10px;
  color: var(--text-secondary);
  line-height: 1.75;
}

ul, ol {
  padding-left: 24px;
  margin-bottom: 12px;
}

li {
  margin-bottom: 6px;
}

strong {
  color: var(--text-primary);
  font-weight: 600;
}

/* ========== CALLOUTS ========== */
.callout {
  padding: 14px 18px;
  border-radius: 6px;
  margin-bottom: 18px;
  border-left: 4px solid;
}

.callout-context {
  background: rgba(59, 130, 246, 0.08);
  border-color: var(--info);
}

.callout-context .callout-header {
  color: var(--info);
}

.callout-info {
  background: rgba(59, 130, 246, 0.08);
  border-color: var(--info);
}

.callout-info .callout-header {
  color: var(--info);
}

.callout-warning {
  background: rgba(245, 158, 11, 0.08);
  border-color: var(--warning);
}

.callout-warning .callout-header {
  color: var(--warning);
}

.callout-danger {
  background: rgba(239, 68, 68, 0.08);
  border-color: var(--danger);
}

.callout-danger .callout-header {
  color: var(--danger);
}

.callout-success {
  background: rgba(34, 197, 94, 0.08);
  border-color: var(--success);
}

.callout-success .callout-header {
  color: var(--success);
}

.callout-tip {
  background: rgba(0, 212, 170, 0.08);
  border-color: var(--accent);
}

.callout-tip .callout-header {
  color: var(--accent);
}

.callout-header {
  font-weight: 600;
  margin-bottom: 6px;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.8px;
}

.callout p, .callout li {
  color: var(--text-secondary);
  font-size: 13.5px;
  line-height: 1.7;
}

.exercise-start-banner {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 20px;
  margin: 24px 0 28px 0;
  border-radius: 8px;
  background: linear-gradient(135deg, rgba(0, 212, 170, 0.1), rgba(59, 130, 246, 0.06));
  border: 1px solid var(--accent);
  border-left: 4px solid var(--accent);
  box-shadow: 0 0 16px rgba(0, 212, 170, 0.1);
}

.exercise-start-icon {
  font-size: 28px;
  flex-shrink: 0;
}

.exercise-start-text {
  color: var(--text-primary);
  font-size: 14px;
  line-height: 1.6;
}

.exercise-start-text strong {
  color: var(--accent);
  font-size: 14px;
  display: block;
  margin-bottom: 2px;
}

.exercise-start-icon {
  font-size: 34px;
  flex-shrink: 0;
  animation: pulse-glow 2s ease-in-out infinite;
}
.exercise-start-text {
  color: var(--text-primary);
  font-size: 15px;
  line-height: 1.6;
}
.exercise-start-text strong {
  color: var(--accent);
  font-size: 16px;
  display: block;
}

.scenario-box {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 24px 28px;
  margin: 24px 0;
  border-radius: 10px;
  background: linear-gradient(135deg, rgba(245, 158, 11, 0.08), rgba(239, 68, 68, 0.06));
  border: 1px solid rgba(245, 158, 11, 0.2);
  border-left: 4px solid var(--warning);
}
.scenario-icon {
  font-size: 32px;
  flex-shrink: 0;
}

.scenario-label {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--warning);
  font-weight: 700;
}

.scenario-text {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.7;
}

.exercise-start-icon {
  font-size: 34px;
  flex-shrink: 0;
  animation: pulse-glow 2s ease-in-out infinite;
}

.exercise-start-text {
  color: var(--text-primary);
  font-size: 15px;
  line-height: 1.6;
}

.exercise-start-text strong {
  color: var(--accent);
  font-size: 16px;
  display: block;
  margin-bottom: 4px;
}

@keyframes pulse-glow {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.7; transform: scale(1.1); }
}

.output-block {
  border-left: 3px solid var(--success);
  background: rgba(34, 197, 94, 0.04);
}

.output-block .code-header .lang {
  color: var(--success);
}

.output-block .copy-btn {
  display: none;
}

/* ========== CODE BLOCKS ========== */
.code-block {
  position: relative;
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 18px;
  overflow: hidden;
}

.code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 14px;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border);
  font-size: 11px;
  color: var(--text-muted);
}

.code-header .lang {
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 600;
}

.copy-btn {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 3px 10px;
  border-radius: 3px;
  cursor: pointer;
  font-family: inherit;
  font-size: 11px;
  transition: all 0.2s;
}

.copy-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

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

pre {
  padding: 14px 16px;
  overflow-x: auto;
  font-size: 13px;
  line-height: 1.6;
}

code {
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
}

.inline-code {
  background: var(--bg-tertiary);
  padding: 1px 7px;
  border-radius: 3px;
  font-size: 13px;
  color: var(--accent);
  font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Consolas', 'Courier New', 'Monaco', monospace;
  border-left: 2px solid var(--accent-dim);
}

/* Syntax highlighting */
.cmd-prompt {
  color: var(--success);
  user-select: none;
}

.cmd-comment {
  color: var(--text-muted);
  font-style: italic;
}

.cmd-flag {
  color: var(--warning);
}

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

.cmd-string {
  color: #f472b6;
}

/* ========== TOGGLES ========== */
.toggle-container {
  margin-bottom: 16px;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.toggle-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: var(--bg-tertiary);
  cursor: pointer;
  transition: background 0.2s;
  user-select: none;
}

.toggle-header:hover {
  background: var(--bg-secondary);
}

.toggle-header .toggle-label {
  font-size: 14px;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 8px;
}

.toggle-header .toggle-arrow {
  transition: transform 0.3s;
  color: var(--text-muted);
}

.toggle-container.open .toggle-arrow {
  transform: rotate(90deg);
}

.toggle-content {
  display: none;
  padding: 16px;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
}

.toggle-container.open .toggle-content {
  display: block;
}

/* ========== EXERCISES ========== */
.exercise-box {
  background: var(--bg-secondary);
  border: 1px solid var(--accent-dim);
  border-radius: 8px;
  margin-bottom: 20px;
  overflow: hidden;
}

.exercise-header {
  background: var(--accent-glow);
  padding: 14px 18px;
  border-bottom: 1px solid var(--accent-dim);
  display: flex;
  align-items: center;
  gap: 10px;
}

.exercise-header .exercise-badge {
  background: var(--accent);
  color: var(--bg-primary);
  padding: 2px 8px;
  border-radius: 3px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
}

.exercise-header .exercise-name {
  font-weight: 600;
  font-size: 15px;
}

.exercise-body {
  padding: 18px;
}

.exercise-goal {
  margin-bottom: 14px;
}

.exercise-goal .goal-label {
  color: var(--accent);
  font-weight: 700;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 4px;
}

.exercise-steps {
  margin-bottom: 14px;
}

.exercise-steps ol {
  padding-left: 20px;
}

.exercise-steps li {
  margin-bottom: 6px;
  font-size: 14px;
}

.exercise-intro {
  background: var(--bg-tertiary);
  border-left: 3px solid var(--accent);
  padding: 10px 14px;
  border-radius: 4px;
  margin-bottom: 14px;
  font-size: 14px;
  color: var(--text-secondary);
}

.exercise-hint {
  display: block;
  color: var(--text-muted);
  font-size: 12px;
  font-style: italic;
  margin-top: 4px;
  margin-bottom: 8px;
  padding-left: 4px;
}

/* ========== LAB SECTION ========== */
.lab-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px;
  margin-bottom: 16px;
  transition: border-color 0.2s;
}

.lab-card:hover {
  border-color: var(--accent-dim);
}

.lab-card h3 {
  color: var(--accent);
  margin-bottom: 8px;
  font-size: 16px;
}

.lab-card p {
  font-size: 14px;
  margin-bottom: 12px;
}

.lab-meta {
  display: flex;
  gap: 16px;
  margin-bottom: 12px;
  font-size: 12px;
}

.lab-meta span {
  display: flex;
  align-items: center;
  gap: 4px;
  color: var(--text-muted);
}

.difficulty-badge {
  padding: 2px 8px;
  border-radius: 3px;
  font-size: 11px;
  font-weight: 600;
}

.difficulty-easy {
  background: rgba(34, 197, 94, 0.15);
  color: var(--success);
}

.difficulty-medium {
  background: rgba(245, 158, 11, 0.15);
  color: var(--warning);
}

.difficulty-hard {
  background: rgba(239, 68, 68, 0.15);
  color: var(--danger);
}

.download-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--bg-tertiary);
  border: 1px solid var(--accent-dim);
  color: var(--accent);
  padding: 8px 16px;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-size: 12px;
  transition: all 0.2s;
  text-decoration: none;
}

.download-btn:hover {
  background: var(--accent-glow);
}

/* ========== TABLES ========== */
.table-container {
  overflow-x: auto;
  margin-bottom: 18px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

th {
  background: var(--bg-tertiary);
  text-align: left;
  padding: 8px 12px;
  border: 1px solid var(--border);
  color: var(--accent);
  font-weight: 600;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

td {
  padding: 7px 12px;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ========== CASE STUDY STEPPER ========== */
.stepper {
  display: flex;
  gap: 4px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.step-indicator {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 11px;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.2s;
}

.step-indicator.active {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-glow);
}

.step-indicator.completed {
  border-color: var(--success);
  color: var(--success);
}

.step-indicator .step-num {
  font-weight: 700;
}

.step-content {
  display: none;
}

.step-content.active {
  display: block;
}

/* ========== CHEATSHEET PANEL ========== */
#cheatsheet-panel {
  position: fixed;
  right: -400px;
  top: 0;
  width: 400px;
  height: 100vh;
  background: var(--bg-secondary);
  border-left: 1px solid var(--border);
  z-index: 200;
  transition: right 0.3s ease;
  display: flex;
  flex-direction: column;
}

#cheatsheet-panel.open {
  right: 0;
}

.cheatsheet-header {
  padding: 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.cheatsheet-header h2 {
  font-size: 15px;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.cheatsheet-close {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 18px;
  cursor: pointer;
}

.cheatsheet-body {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
}

.cheatsheet-section {
  margin-bottom: 16px;
}

.cheatsheet-section h3 {
  font-size: 12px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 8px;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--border);
}

.cheatsheet-cmd {
  background: var(--bg-code);
  padding: 6px 10px;
  border-radius: 3px;
  font-size: 12px;
  margin-bottom: 4px;
  color: var(--accent);
  cursor: pointer;
  position: relative;
}

.cheatsheet-cmd:hover::after {
  content: 'Click to copy';
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 10px;
  color: var(--text-muted);
}

.cheatsheet-desc {
  font-size: 11px;
  color: var(--text-muted);
  margin-bottom: 8px;
  padding-left: 10px;
}

/* ========== GENERIC PANEL ========== */
.panel {
  position: fixed;
  right: -480px;
  top: 0;
  width: 480px;
  height: 100vh;
  background: var(--bg-secondary);
  border-left: 1px solid var(--border);
  z-index: 200;
  transition: right 0.3s ease;
  display: flex;
  flex-direction: column;
  box-shadow: -4px 0 24px rgba(0, 0, 0, 0.3);
}

.panel.open {
  right: 0;
}

.panel-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.panel-header h2 {
  font-size: 14px;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.panel-close {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 22px;
  cursor: pointer;
  padding: 2px 8px;
  border-radius: 4px;
  transition: all 0.2s;
}

.panel-close:hover {
  color: var(--text-primary);
  border-color: var(--text-muted);
}

.panel-body {
  flex: 1;
  overflow-y: auto;
  padding: 16px 20px;
}

.terminal-panel-body {
  padding: 0;
  display: flex;
  flex-direction: column;
  height: 100%;
}

.terminal-container {
  background: #000;
  border-radius: 8px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  height: 100%;
  min-height: 0;
}

.t-header {
  background: var(--bg-tertiary);
  padding: 8px 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.t-title {
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  font-family: var(--font-mono);
}

.t-status {
  font-size: 10px;
  color: var(--accent);
}

.t-header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.t-minimize-btn {
  background: none;
  border: 1px solid #444;
  color: var(--text-muted);
  width: 24px;
  height: 24px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
  line-height: 1;
}

.t-minimize-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-glow);
}

.t-body {
  flex: 1;
  overflow-y: auto;
  min-height: 0;
  padding: 12px;
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-secondary);
  background: #000;
}

.t-line {
  margin-bottom: 2px;
}

.t-line .t-prompt {
  color: var(--success);
}

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

.t-output {
  margin-bottom: 4px;
  white-space: pre-wrap;
  word-break: break-all;
}

.t-output.t-success { color: var(--accent); }
.t-output.t-error { color: var(--danger); }
.t-output.t-warning { color: var(--warning); }
.t-output.t-info { color: var(--info); }

.t-input-wrap {
  display: flex;
  align-items: center;
  padding: 8px 14px;
  background: #0a0a0a;
  border-top: 1px solid #222;
  flex-shrink: 0;
}

.t-prompt-label {
  color: var(--success);
  font-family: var(--font-mono);
  font-size: 14px;
  white-space: nowrap;
  user-select: none;
}

.t-input-field {
  position: relative;
  flex: 1;
  display: inline-flex;
  align-items: center;
  margin-left: 6px;
  min-width: 60px;
}

.t-text-mirror {
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 14px;
  white-space: pre;
  pointer-events: none;
}

.t-input-field:not(:focus-within) .t-text-mirror:empty::after {
  content: 'Befehl eingeben...';
  color: var(--text-muted);
  opacity: 0.4;
}

.t-block-cursor {
  display: inline-block;
  width: 8px;
  height: 17px;
  background: var(--accent);
  flex-shrink: 0;
  pointer-events: none;
  margin-left: 1px;
  vertical-align: text-bottom;
}

.t-input-field:focus-within .t-block-cursor {
  animation: blockBlink 1s step-end infinite;
}

.t-input-field:not(:focus-within) .t-block-cursor {
  display: none;
}

.t-input {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background: none;
  border: none;
  color: transparent;
  caret-color: transparent;
  font-family: var(--font-mono);
  font-size: 14px;
  outline: none;
  padding: 0;
  cursor: text;
  z-index: 1;
}

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

.inline-terminal {
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-top: 16px;
  height: 280px;
  display: flex;
  flex-direction: column;
  background: #000;
  overflow: hidden;
  flex-shrink: 0;
}

.it-header {
  background: var(--bg-tertiary);
  padding: 6px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.it-title {
  font-size: 10px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  font-family: var(--font-mono);
}

.it-suggestion {
  display: none;
  padding: 5px 12px;
  background: rgba(0, 212, 170, 0.06);
  border-bottom: 1px solid rgba(0, 212, 170, 0.15);
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
  transition: background 0.2s;
  flex-shrink: 0;
  align-items: center;
  gap: 6px;
}

.it-suggestion.visible {
  display: flex;
}

.it-suggestion:hover {
  background: rgba(0, 212, 170, 0.12);
}

.it-body {
  flex: 1;
  overflow-y: auto;
  padding: 8px 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-secondary);
  background: #000;
}

.it-body .t-line,
.it-body .it-line { margin-bottom: 1px; }
.it-body .t-line .t-prompt,
.it-body .it-line .it-prompt { color: var(--success); }
.it-body .t-line .t-cmd,
.it-body .it-line .it-cmd { color: var(--text-primary); }
.it-body .t-output,
.it-body .it-output { margin-bottom: 2px; white-space: pre-wrap; word-break: break-all; }
.it-body .t-output.t-success,
.it-body .it-output.it-success { color: var(--accent); }
.it-body .t-output.t-error,
.it-body .it-output.it-error { color: var(--danger); }
.it-body .t-output.t-warning,
.it-body .it-output.it-warning { color: var(--warning); }
.it-body .t-output.t-info,
.it-body .it-output.it-info { color: var(--info); }

.it-input-wrap {
  display: flex;
  align-items: center;
  padding: 6px 12px;
  background: #000;
  flex-shrink: 0;
}

.it-prompt {
  color: var(--success);
  font-family: var(--font-mono);
  font-size: 13px;
  white-space: nowrap;
  user-select: none;
}

.it-input {
  flex: 1;
  background: none;
  border: none;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 13px;
  outline: none;
  margin-left: 4px;
  padding: 3px 0;
  caret-color: var(--accent);
  text-shadow: 0 0 1px var(--accent);
  cursor: text;
}

.it-input::placeholder {
  color: var(--text-muted);
  opacity: 0.5;
}

.ref-search-wrap {
  margin-bottom: 16px;
  position: sticky;
  top: 0;
  background: var(--bg-secondary);
  padding: 8px 0;
  z-index: 5;
}

.ref-search {
  width: 100%;
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px 14px;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 14px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.ref-search:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(0, 212, 170, 0.12);
}

.ref-search::placeholder {
  color: var(--text-muted);
  opacity: 0.6;
}

.ref-section-block {
  margin-bottom: 16px;
}

.ref-section-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ========== OVERLAY ========== */
.overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 150;
}

.overlay.active {
  display: block;
}

/* ========== DECISION CARDS ========== */
.decision-card {
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 18px;
  margin-bottom: 18px;
  margin-top: 24px;
}

.decision-card .question {
  color: var(--warning);
  font-weight: 600;
  margin-bottom: 12px;
  font-size: 14px;
  line-height: 1.6;
}

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

.decision-option {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 10px 14px;
  cursor: pointer;
  transition: all 0.2s;
  font-size: 13.5px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.decision-option:hover {
  border-color: var(--accent);
}

.decision-option.correct {
  border-color: var(--success);
  background: rgba(34, 197, 94, 0.08);
}

.decision-option.wrong {
  border-color: var(--danger);
  background: rgba(239, 68, 68, 0.08);
}

.decision-feedback {
  margin-top: 10px;
  padding: 10px 14px;
  border-radius: 4px;
  font-size: 13px;
  line-height: 1.6;
  display: none;
}

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

.decision-feedback.correct {
  background: rgba(34, 197, 94, 0.08);
  color: var(--success);
  border: 1px solid rgba(34, 197, 94, 0.3);
}

.decision-feedback.wrong {
  background: rgba(239, 68, 68, 0.08);
  color: var(--danger);
  border: 1px solid rgba(239, 68, 68, 0.3);
}

/* ========== MARK COMPLETE BTN ========== */
.complete-section-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  padding: 11px;
  background: var(--bg-tertiary);
  border: 1px solid var(--accent-dim);
  color: var(--accent);
  border-radius: 6px;
  cursor: pointer;
  font-family: inherit;
  font-size: 13px;
  font-weight: 600;
  transition: all 0.2s;
  margin-top: 28px;
}

.complete-section-btn:hover {
  background: var(--accent-glow);
}

.complete-section-btn.done {
  background: rgba(34, 197, 94, 0.1);
  border-color: var(--success);
  color: var(--success);
}

/* ========== NAV BUTTONS ========== */
.nav-buttons {
  display: flex;
  justify-content: space-between;
  margin-top: 36px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

.nav-btn {
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 10px 20px;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-size: 13px;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-glow);
}

/* ========== RESPONSIVE ========== */
@media (max-width: 768px) {
  #sidebar {
    position: fixed;
    transform: translateX(-100%);
    height: 100vh;
  }

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

  #sidebar.open #sidebar-nav {
    padding-bottom: 60px;
  }

  #menu-toggle {
    display: block;
  }

  #content {
    padding: 5px 16px;
  }

  .chapter-title {
    font-size: 22px;
  }

  #terminal-bottom {
    height: 50vh;
    flex-shrink: 0;
    overflow: hidden;
    border-top: 2px solid var(--border);
    transition: height 0.2s ease;
  }

  #terminal-bottom.open {
    height: 320px;
  }

  #terminal-bottom .terminal-container {
    border-radius: 0;
  }
}

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

.fade-in {
  animation: fadeIn 0.3s ease forwards;
}

/* ========== WELCOME ========== */
.welcome-hero {
  text-align: center;
  padding: 32px 24px 24px;
}

.welcome-hero-eyebrow {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 3px;
  color: var(--accent);
  margin-bottom: 12px;
  font-family: var(--font-mono);
}

.welcome-hero h1 {
  font-size: 32px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
  line-height: 1.2;
}

.welcome-hero-desc {
  color: var(--text-secondary);
  font-size: 14px;
  max-width: 480px;
  margin: 0 auto 24px;
  line-height: 1.65;
}

.welcome-cta {
  background: var(--accent);
  color: #0a0e17;
  font-size: 13px;
  font-weight: 600;
  padding: 9px 24px;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}

.welcome-cta:hover {
  background: var(--accent-dim);
  transform: translateY(-1px);
}

.welcome-note {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  margin-bottom: 28px;
  color: var(--text-muted);
  font-size: 12px;
  line-height: 1.4;
  border-left: 2px solid var(--border-light);
}

.welcome-note svg {
  flex-shrink: 0;
  color: var(--text-muted);
  opacity: 0.6;
}

.welcome-modules {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.welcome-module {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 18px 20px;
  cursor: pointer;
  transition: border-color 0.2s;
}

.welcome-module:hover {
  border-color: var(--accent);
}

.welcome-module-left {
  flex-shrink: 0;
}

.welcome-module-num {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: var(--bg-tertiary);
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
  font-family: var(--font-mono);
}

.welcome-module-body {
  flex: 1;
  min-width: 0;
}

.welcome-module-body h2 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0 0 3px;
}

.welcome-module-body p {
  font-size: 12.5px;
  color: var(--text-muted);
  margin: 0;
  line-height: 1.4;
}

.welcome-module-arrow {
  color: var(--accent);
  font-size: 16px;
  flex-shrink: 0;
  opacity: 0;
  transition: opacity 0.15s;
}

.welcome-module:hover .welcome-module-arrow {
  opacity: 1;
}

.feature-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin: 20px 0 28px;
}

.feature-card {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 14px;
  transition: all 0.2s;
}

.feature-card:hover {
  border-color: var(--accent);
  box-shadow: 0 0 12px rgba(0, 212, 170, 0.08);
}

.feature-card .feature-icon {
  font-size: 20px;
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-tertiary);
  border-radius: 8px;
}

.feature-card .feature-text {
  min-width: 0;
}

.feature-card h3 {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0 0 2px;
  letter-spacing: 0.2px;
}

.feature-card p {
  font-size: 11.5px;
  color: var(--text-muted);
  margin: 0;
  line-height: 1.35;
}

.chapter-preview-card {
  cursor: default;
  pointer-events: none;
}

.chapter-preview-card:hover {
  border-color: var(--border);
}

.slide-nav-hint {
  text-align: center;
  color: var(--text-muted);
  font-size: 13px;
  margin-top: 20px;
  padding: 10px 16px;
  border: 1px dashed var(--accent);
  border-radius: 8px;
  letter-spacing: 0.2px;
  background: var(--accent-glow);
}

/* ========== LISTS ========== */
.styled-list {
  list-style: none;
  padding-left: 0;
}

.styled-list li {
  padding-left: 20px;
  position: relative;
  margin-bottom: 8px;
}

.styled-list li::before {
  content: '>';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

.numbered-list {
  padding-left: 24px;
}

.numbered-list li {
  margin-bottom: 10px;
}

/* ========== TAB COMPONENT ========== */
.tabs {
  display: flex;
  gap: 2px;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.tab-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  padding: 8px 16px;
  cursor: pointer;
  font-family: inherit;
  font-size: 12px;
  transition: all 0.2s;
  border-bottom: 2px solid transparent;
}

.tab-btn.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

/* ========== HIGHLIGHT KEYWORD ========== */
.kw {
  color: var(--warning);
  font-weight: 600;
}

.file {
  color: #f472b6;
}

.path {
  color: #a78bfa;
}

.tool {
  color: var(--accent);
  font-weight: 600;
}

.code-block pre {
  white-space: pre;
  word-break: normal;
  overflow-wrap: normal;
}

.code-block code {
  font-size: 14px;
}

.lab-card .download-btn {
  margin-top: 10px;
}

.exercise-box .toggle-container {
  margin-top: 12px;
  margin-bottom: 8px;
}

.step-content {
  animation: fadeIn 0.3s ease;
}

#content img {
  max-width: 100%;
  border-radius: 6px;
}

.lab-card h3 {
  color: var(--accent);
  margin-bottom: 8px;
  font-size: 16px;
}

.callout ul {
  padding-left: 20px;
}

.callout li {
  font-size: 14px;
  color: var(--text-secondary);
}

@media (max-width: 768px) {
  .stepper {
    gap: 2px;
  }
  .step-indicator {
    font-size: 10px;
    padding: 4px 8px;
  }
  .feature-grid {
    grid-template-columns: 1fr;
  }
  .welcome-hero h1 {
    font-size: 28px;
  }
  .welcome-stats {
    grid-template-columns: repeat(2, 1fr);
  }
  .welcome-module-tags span {
    font-size: 11px;
    padding: 3px 8px;
  }
}

/* ========== SIDEBAR TABS ========== */
.sidebar-tabs {
  display: flex;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.sidebar-tab {
  flex: 1;
  padding: 10px 8px;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-muted);
  font-family: inherit;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  cursor: pointer;
  transition: all 0.2s;
}

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

.sidebar-tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.sidebar-tab-content {
  display: none;
  flex-direction: column;
  flex: 1;
  overflow: hidden;
}

.sidebar-tab-content.active {
  display: flex;
}

#sidebar-tab-ref {
  overflow-y: auto;
  padding: 0;
}

#sidebar-tab-ref .ref-search-wrap {
  padding: 12px 12px 8px;
  flex-shrink: 0;
}

.ref-commands-list {
  overflow-y: auto;
  flex: 1;
  padding: 0 8px 8px;
}

.ref-cmd {
  display: flex;
  flex-direction: column;
  padding: 8px 10px;
  cursor: pointer;
  border-radius: 4px;
  transition: background 0.15s;
  border-bottom: 1px solid rgba(255,255,255,0.03);
}

.ref-cmd:hover {
  background: var(--bg-tertiary);
}

.ref-cmd-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-primary);
  font-family: var(--font-mono);
}

.ref-cmd-preview {
  font-size: 10px;
  color: var(--text-muted);
  font-family: var(--font-mono);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin-top: 2px;
}

.ref-detail-panel {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg-primary);
  z-index: 10;
  overflow-y: auto;
  padding: 12px;
}

.ref-detail-close {
  position: sticky;
  top: 0;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  width: 28px;
  height: 28px;
  border-radius: 50%;
  cursor: pointer;
  font-size: 15px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 8px;
}

.ref-detail-close:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.ref-detail-title {
  color: var(--accent);
  font-size: 15px;
  margin-bottom: 10px;
}

.ref-detail-section {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.ref-detail-panel .s-code {
  margin: 8px 0;
}

.ref-detail-panel .s-table-wrap {
  margin: 8px 0;
}

.ref-detail-panel .s-text {
  font-size: 12px;
  line-height: 1.5;
  color: var(--text-secondary);
}

/* ========== SLIDE NAV BAR ========== */
/* ========== SLIDE NAV IN TOPBAR ========== */
#slide-nav-topbar {
  display: none;
  align-items: center;
  gap: 6px;
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 4px 8px;
}

.slide-prev,
.slide-next {
  height: 32px;
  border-radius: 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  transition: all 0.2s;
  flex-shrink: 0;
  padding: 0 14px;
  white-space: nowrap;
  font-family: inherit;
}

.slide-prev:hover,
.slide-next:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-glow);
  box-shadow: 0 0 12px rgba(0, 212, 170, 0.15);
}

.slide-next-primary {
  background: var(--accent);
  color: var(--bg-primary);
  border-color: var(--accent);
  font-weight: 600;
}

.slide-next-primary:hover {
  background: var(--accent-dim);
  color: var(--bg-primary);
  box-shadow: 0 0 16px rgba(0, 212, 170, 0.3);
}

.slide-dots {
  display: flex;
  gap: 5px;
  align-items: center;
  padding: 0 6px;
}

.slide-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--border-light);
  cursor: pointer;
  transition: all 0.25s;
}

.slide-dot:hover {
  background: var(--text-muted);
  transform: scale(1.4);
}

.slide-dot.active {
  background: var(--accent);
  transform: scale(1.5);
  box-shadow: 0 0 8px rgba(0, 212, 170, 0.5);
}

.slide-counter {
  display: none;
}

.slide-center {
  display: none;
}

/* ========== TERMINAL BOTTOM ========== */
#terminal-bottom {
  height: 0;
  flex-shrink: 0;
  background: #000;
  overflow: hidden;
  transition: height 0.25s ease;
  display: flex;
  flex-direction: column;
}

#terminal-bottom.open {
  height: 320px;
}

#terminal-container {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

#terminal-bottom .terminal-container {
  border-radius: 0;
  flex: 1;
  min-height: 0;
}

.terminal-resize-handle {
  height: 6px;
  background: var(--bg-tertiary);
  cursor: ns-resize;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
}

.terminal-resize-handle::after {
  content: '';
  width: 40px;
  height: 3px;
  background: var(--border-light);
  border-radius: 2px;
  transition: background 0.2s;
}

.terminal-resize-handle:hover {
  background: var(--bg-secondary);
}

.terminal-resize-handle:hover::after {
  background: var(--accent);
}

/* ========== SLIDE SYSTEM ========== */
.slide-container {
  position: relative;
}

.slide {
  display: none;
}

.slide.active {
  display: block;
  animation: slideFadeIn 0.25s ease;
}

@keyframes slideFadeIn {
  from { opacity: 0; transform: translateX(16px); }
  to { opacity: 1; transform: translateX(0); }
}

.slide-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 0;
  margin-top: 20px;
  border-top: 1px solid var(--border);
  gap: 12px;
}

/* ========== TRY BUTTON ========== */
.exercise-solution {
  margin-top: 16px;
  padding: 12px 16px;
  background: rgba(0, 212, 170, 0.06);
  border: 1px solid var(--accent-dim);
  border-radius: 6px;
}

.exercise-solution .solution-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 8px;
}

.exercise-solution p {
  margin: 4px 0;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.5;
}

.exercise-lock-msg {
  margin: 12px 0;
  padding: 10px 14px;
  background: rgba(255, 180, 0, 0.08);
  border: 1px solid rgba(255, 180, 0, 0.2);
  border-radius: 6px;
  font-size: 14px;
  color: var(--warning);
  line-height: 1.5;
}

.slide-next:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.slide-next:disabled:hover {
  border-color: var(--border);
  color: var(--text-secondary);
  background: var(--bg-tertiary);
  box-shadow: none;
}

/* ========== TRY BUTTON ========== */
.try-btn {
  background: rgba(0, 212, 170, 0.08);
  border: 1px solid var(--accent-dim);
  color: var(--accent);
  padding: 3px 10px;
  border-radius: 3px;
  cursor: pointer;
  font-family: inherit;
  font-size: 11px;
  transition: all 0.2s;
}

.try-btn:hover {
  background: var(--accent-glow);
  border-color: var(--accent);
}

/* ========== SIDEBAR FOOTER ========== */
.sidebar-footer {
  padding: 12px 16px;
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

/* ========== CHALLENGE UI ========== */
.lab-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px;
  margin-bottom: 24px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.lab-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
  flex-wrap: wrap;
  gap: 8px;
}

.difficulty-badge {
  padding: 4px 12px;
  border-radius: 3px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
}

.difficulty-easy {
  background: rgba(34, 197, 94, 0.15);
  color: #22c55e;
}

.difficulty-medium {
  background: rgba(234, 179, 8, 0.15);
  color: #eab308;
}

.difficulty-hard {
  background: rgba(234, 88, 12, 0.15);
  color: #ef4444;
}

.challenge-status {
  font-size: 12px;
  font-weight: 600;
}

.challenge-questions {
  margin: 16px 0;
}

.challenge-question {
  margin-bottom: 16px;
}

.question-text {
  font-size: 15px;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.challenge-select {
  width: 100%;
  padding: 8px 12px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-primary);
  font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Consolas', 'Courier New', 'Monaco', monospace;
  font-size: 15px;
}

.challenge-select:focus {
  outline: none;
  border-color: var(--accent);
}

.challenge-input {
  margin: 16px 0;
}

.challenge-input-field {
  width: 100%;
  padding: 8px 12px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-primary);
  font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Consolas', 'Courier New', 'Monaco', monospace;
  font-size: 15px;
  margin-bottom: 12px;
}

.challenge-input-field:focus {
  outline: none;
  border-color: var(--accent);
}

.challenge-check-btn {
  background: var(--accent);
  color: var(--bg-primary);
  border: none;
  border-radius: 4px;
  padding: 8px 16px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}

.challenge-check-btn:hover {
  background: var(--accent-dim);
  transform: translateY(-1px);
}

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

.challenge-feedback {
  margin: 16px 0;
  padding: 12px 16px;
  border-radius: 6px;
  font-size: 15px;
}

.feedback-success {
  background: rgba(34, 197, 94, 0.1);
  border-left: 4px solid #22c55e;
  color: #16a34a;
}

.feedback-error {
  background: rgba(234, 88, 12, 0.1);
  border-left: 4px solid #ef4444;
  color: #b91c1c;
}

.feedback-warning {
  background: rgba(245, 158, 11, 0.1);
  border-left: 4px solid #eab308;
  color: #a16207;
}

.challenge-stats {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  background: var(--bg-tertiary);
  border-radius: 6px;
  font-size: 14px;
}

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

.challenge-completed {
  color: #22c55e;
  font-weight: 600;
}

.challenge-hint-btn {
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 6px 12px;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
  margin-top: 12px;
}

.challenge-hint-btn:hover {
  background: var(--accent-glow);
  color: var(--accent);
  border-color: var(--accent);
}

.challenge-hint {
  margin: 12px 0;
  padding: 12px 16px;
  background: rgba(245, 158, 11, 0.08);
  border-left: 4px solid #eab308;
  border-radius: 6px;
  font-size: 14px;
  color: var(--text-secondary);
}

.download-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  background: var(--accent-glow);
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 4px;
  font-size: 14px;
  text-decoration: none;
  transition: all 0.2s;
  font-family: inherit;
}

.download-btn:hover {
  background: var(--accent);
  color: var(--bg-primary);
  transform: translateY(-1px);
}

@media (max-width: 768px) {
  .lab-meta {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .challenge-stats {
    flex-direction: column;
    gap: 8px;
    align-items: flex-start;
  }
  
  .challenge-input-field {
    font-size: 16px;
  }
}

/* ========== REFERENCE DETAIL STYLES ========== */
.ref-detail-panel .s-code {
  background: #111;
  border-radius: 6px;
  margin: 8px 0;
  overflow: hidden;
}

.ref-detail-panel .s-code pre {
  padding: 10px 12px;
  margin: 0;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.5;
  color: var(--text-secondary);
}

.ref-detail-panel .s-code pre code {
  color: var(--text-primary);
}

.ref-detail-panel .s-code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px 12px;
  background: #1a1a1a;
  border-bottom: 1px solid #333;
}

.ref-detail-panel .s-code-label {
  font-size: 11px;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.ref-detail-panel .s-copy {
  background: rgba(0, 212, 170, 0.08);
  border: 1px solid var(--accent-dim);
  color: var(--accent);
  padding: 3px 10px;
  border-radius: 3px;
  cursor: pointer;
  font-family: inherit;
  font-size: 11px;
  transition: all 0.2s;
}

.ref-detail-panel .s-copy:hover {
  background: var(--accent-glow);
  border-color: var(--accent);
}

.ref-detail-panel .s-table-wrap {
  margin: 8px 0;
  overflow-x: auto;
}

.ref-detail-panel .s-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 12px;
}

.ref-detail-panel .s-table th,
.ref-detail-panel .s-table td {
  padding: 6px 10px;
  border: 1px solid var(--border);
  text-align: left;
}

.ref-detail-panel .s-table th {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  font-weight: 600;
}

.ref-detail-panel .s-inline {
  font-family: var(--font-mono);
  font-size: 12px;
  background: rgba(0, 212, 170, 0.08);
  padding: 1px 5px;
  border-radius: 3px;
  color: var(--accent);
}

/* ========== HUB VIEW ========== */
.hub-header {
  text-align: center;
  padding: 60px 20px 40px;
}

.hub-eyebrow {
  font-size: 12px;
  letter-spacing: 3px;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 8px;
}

.hub-title {
  font-size: 36px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.hub-desc {
  font-size: 15px;
  color: var(--text-secondary);
  max-width: 500px;
  margin: 0 auto;
}

.hub-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  max-width: 700px;
  margin: 0 auto 40px;
  padding: 0 20px;
}

.hub-card {
  display: flex;
  align-items: center;
  gap: 20px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  cursor: pointer;
  transition: all 0.2s;
}

.hub-card:hover {
  border-color: var(--lab-accent, var(--accent));
  box-shadow: 0 0 20px rgba(0, 212, 170, 0.08);
  transform: translateY(-1px);
}

.hub-card-icon {
  font-size: 36px;
  width: 64px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-tertiary);
  border-radius: 12px;
  flex-shrink: 0;
}

.hub-card-body {
  flex: 1;
  min-width: 0;
}

.hub-card-body h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0 0 6px;
}

.hub-card-body p {
  font-size: 13px;
  color: var(--text-muted);
  margin: 0 0 12px;
  line-height: 1.4;
}

.hub-card-progress {
  display: flex;
  align-items: center;
  gap: 12px;
}

.hub-card-progress .progress-bar-container {
  flex: 1;
  height: 4px;
}

.hub-progress-text {
  font-size: 11px;
  color: var(--text-muted);
  white-space: nowrap;
}

.nav-back-btn {
  padding: 10px 20px;
  color: var(--accent);
  font-size: 13px;
  cursor: pointer;
  border-bottom: 1px solid var(--border);
  margin-bottom: 4px;
  transition: background 0.2s;
}

.nav-back-btn:hover {
  background: var(--bg-tertiary);
}

@media (max-width: 768px) {
  .hub-title {
    font-size: 26px;
  }
  .hub-card {
    flex-direction: column;
    text-align: center;
    gap: 12px;
  }
  .hub-card-progress {
    justify-content: center;
  }
}