/* CSS Design System — Interactive Python Course Web App (Revised) */

:root {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --bg-card: #ffffff;
  --bg-sidebar: #0f172a;
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --text-inverse: #f8fafc;
  
  --brand-primary: #2563eb;
  --brand-primary-hover: #1d4ed8;
  --brand-light: #eff6ff;
  --brand-accent: #3b82f6;
  
  --success: #16a34a;
  --success-light: #f0fdf4;
  --warning: #d97706;
  --warning-light: #fffbeb;
  --danger: #dc2626;
  --danger-light: #fef2f2;
  
  --border-color: #e2e8f0;
  --border-focus: #3b82f6;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg-primary: #0b0f19;
  --bg-secondary: #1e293b;
  --bg-tertiary: #0f172a;
  --bg-card: #1e293b;
  --bg-sidebar: #020617;
  
  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --text-inverse: #0f172a;
  
  --brand-primary: #3b82f6;
  --brand-primary-hover: #60a5fa;
  --brand-light: #1e3a8a;
  --brand-accent: #60a5fa;
  
  --border-color: #334155;
  --border-focus: #60a5fa;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.5);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--brand-primary);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  text-decoration: underline;
}

#app-container {
  display: flex;
  flex: 1;
  min-height: 100vh;
}

/* Sidebar Navigation */
.sidebar {
  width: 310px;
  background-color: var(--bg-sidebar);
  color: #94a3b8;
  display: flex;
  flex-direction: column;
  border-right: 1px solid rgba(255, 255, 255, 0.1);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  z-index: 50;
  transition: var(--transition);
}

.sidebar-header {
  padding: 1.5rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.15rem;
  font-weight: 700;
  color: #f8fafc;
}

.sidebar-brand svg {
  color: #3b82f6;
}

.nav-section-title {
  padding: 0.75rem 1.5rem 0.25rem 1.5rem;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #64748b;
}

.nav-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.5rem;
  color: #cbd5e1;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  border-left: 3px solid transparent;
  transition: var(--transition);
}

.nav-item:hover {
  background: rgba(255, 255, 255, 0.05);
  color: #f8fafc;
}

.nav-item.active {
  background: rgba(59, 130, 246, 0.15);
  color: #60a5fa;
  border-left-color: #3b82f6;
  font-weight: 600;
}

.nav-badge {
  font-size: 0.7rem;
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.1);
  color: #94a3b8;
}

.nav-item.active .nav-badge {
  background: rgba(59, 130, 246, 0.3);
  color: #93c5fd;
}

/* Main Content Area */
.main-wrapper {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.top-bar {
  height: 64px;
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 40;
}

.mobile-nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
}

.bar-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.theme-toggle-btn {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 0.5rem 0.9rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: var(--transition);
}

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

.main-content {
  padding: 2.5rem;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

/* Cards & Hero */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
  margin-bottom: 2rem;
  transition: var(--transition);
}

.card-header {
  margin-bottom: 1.5rem;
}

[data-theme="dark"] .card h3[style*="var(--brand-primary)"],
[data-theme="dark"] .card h3[style*="--brand-primary"] {
  color: #60a5fa !important;
}

[data-theme="dark"] .card h3[style*="var(--warning)"],
[data-theme="dark"] .card h3[style*="--warning"] {
  color: #fbbf24 !important;
}

.hero {
  background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
  color: white;
  border-radius: var(--radius-lg);
  padding: 3rem 2.5rem;
  margin-bottom: 2.5rem;
  box-shadow: var(--shadow-md);
}

.hero h1 {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 1rem;
  line-height: 1.2;
}

.hero p {
  font-size: 1.1rem;
  color: #94a3b8;
  max-width: 800px;
}

/* Module Grid */
.module-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
}

.module-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

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

.module-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 1rem;
}

.module-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.module-card-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
}

.badge-primary {
  background: var(--brand-light);
  color: var(--brand-primary);
}

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

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

[data-theme="dark"] .badge-primary {
  background: rgba(59, 130, 246, 0.2);
  color: #60a5fa;
  border: 1px solid rgba(59, 130, 246, 0.35);
}

[data-theme="dark"] .badge-warning {
  background: rgba(245, 158, 11, 0.2);
  color: #fbbf24;
  border: 1px solid rgba(245, 158, 11, 0.35);
}

[data-theme="dark"] .badge-success {
  background: rgba(16, 185, 129, 0.2);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.35);
}

/* Deep Theoretical Content Styling */
.theory-block {
  margin-bottom: 2.5rem;
}

.theory-block h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 0.85rem;
  color: var(--text-primary);
  border-left: 4px solid var(--brand-primary);
  padding-left: 0.75rem;
}

.theory-block h4 {
  font-size: 1.05rem;
  font-weight: 700;
  margin: 1.25rem 0 0.5rem 0;
  color: var(--brand-primary);
}

[data-theme="dark"] .theory-block h4 {
  color: #60a5fa !important;
}

.theory-block p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  font-size: 1.02rem;
  line-height: 1.7;
}

.theory-block ul, .theory-block ol {
  margin-left: 1.75rem;
  margin-bottom: 1.25rem;
  color: var(--text-secondary);
}

.theory-block li {
  margin-bottom: 0.4rem;
}

/* Callout Boxes */
.callout-box {
  padding: 1.25rem;
  border-radius: var(--radius-md);
  margin: 1.25rem 0;
  border-left: 4px solid;
}

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

.callout-warning {
  background: var(--warning-light);
  border-color: var(--warning);
  color: var(--text-primary);
}

.callout-danger {
  background: var(--danger-light);
  border-color: var(--danger);
  color: var(--text-primary);
}

[data-theme="dark"] .callout-info {
  background: var(--brand-light);
  border-color: var(--brand-primary);
  color: var(--text-primary);
}

[data-theme="dark"] .callout-info strong {
  color: #ffffff;
}

[data-theme="dark"] .callout-info p,
[data-theme="dark"] .callout-info ul,
[data-theme="dark"] .callout-info ol,
[data-theme="dark"] .callout-info li {
  color: #e2e8f0;
}

[data-theme="dark"] .callout-info code {
  color: #93c5fd;
  background: rgba(255, 255, 255, 0.12);
}

[data-theme="dark"] .callout-warning {
  color: #0f172a;
}

[data-theme="dark"] .callout-warning h4,
[data-theme="dark"] .callout-warning p,
[data-theme="dark"] .callout-warning ul,
[data-theme="dark"] .callout-warning ol,
[data-theme="dark"] .callout-warning li {
  color: #0f172a;
}

[data-theme="dark"] .callout-warning strong {
  color: #0f172a;
  font-weight: 700;
}

[data-theme="dark"] .callout-warning em {
  color: #334155;
}

[data-theme="dark"] .callout-warning code {
  color: #0f172a !important;
  background: rgba(0, 0, 0, 0.07) !important;
}

[data-theme="dark"] .callout-danger {
  color: #0f172a;
}

[data-theme="dark"] .callout-danger h4,
[data-theme="dark"] .callout-danger p,
[data-theme="dark"] .callout-danger ul,
[data-theme="dark"] .callout-danger ol,
[data-theme="dark"] .callout-danger li {
  color: #0f172a;
}

[data-theme="dark"] .callout-danger strong {
  color: #0f172a;
  font-weight: 700;
}

[data-theme="dark"] .callout-danger em {
  color: #334155;
}

[data-theme="dark"] .callout-danger code {
  color: #0f172a !important;
  background: rgba(0, 0, 0, 0.07) !important;
}

/* Code Example Box */
.code-example-block {
  background: #0f172a;
  color: #f8fafc;
  padding: 1.25rem;
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  margin: 1.25rem 0;
  overflow-x: auto;
  border: 1px solid #1e293b;
}

.code-example-block .code-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #94a3b8;
  margin-bottom: 0.5rem;
  border-bottom: 1px solid #334155;
  padding-bottom: 0.25rem;
}

/* Comparison Tables */
.comparison-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.25rem 0;
  font-size: 0.95rem;
}

.comparison-table th, .comparison-table td {
  padding: 0.75rem 1rem;
  border: 1px solid var(--border-color);
  text-align: left;
}

.comparison-table th {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  font-weight: 700;
}

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

.comparison-table td strong {
  color: var(--text-primary);
}

.table-wrapper {
  overflow-x: auto;
  margin: 1.25rem 0;
}

.styled-list {
  margin-left: 1.5rem;
  margin-bottom: 1.25rem;
  color: var(--text-secondary);
}

.styled-list li {
  margin-bottom: 0.4rem;
}

.styled-list li strong {
  color: var(--text-primary);
}

/* Output Preview Block */
.output-block {
  background: #090d16;
  border: 1px solid #1e293b;
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  margin: 1rem 0 1.5rem 0;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: #38bdf8;
}

.output-block .output-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #94a3b8;
  margin-bottom: 0.4rem;
  border-bottom: 1px solid #1e293b;
  padding-bottom: 0.25rem;
}

.output-block pre {
  margin: 0;
  white-space: pre-wrap;
  color: #a7f3d0;
}

/* Step-by-step breakdown */
.step-explanation {
  background: var(--bg-tertiary);
  border-left: 3px solid var(--brand-accent);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 1rem 0;
}

.step-explanation ol {
  margin-left: 1.25rem;
  margin-bottom: 0;
}

.step-explanation li {
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

.step-explanation li strong {
  color: var(--text-primary);
}

/* Mistake Cards Grid */
.mistake-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin: 1rem 0;
}

@media (max-width: 768px) {
  .mistake-grid {
    grid-template-columns: 1fr;
  }
}

.mistake-box {
  padding: 1rem;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
}

.mistake-bad {
  background: var(--danger-light);
  border: 1px solid rgba(220, 38, 38, 0.3);
  color: var(--text-primary);
}

.mistake-bad .mistake-title {
  font-weight: 700;
  color: #dc2626;
  margin-bottom: 0.4rem;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.mistake-good {
  background: var(--success-light);
  border: 1px solid rgba(22, 163, 74, 0.3);
  color: var(--text-primary);
}

.mistake-good .mistake-title {
  font-weight: 700;
  color: #16a34a;
  margin-bottom: 0.4rem;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

/* Inline Code Styling */
code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  padding: 0.15rem 0.35rem;
  border-radius: 4px;
  background: rgba(0, 0, 0, 0.05);
  color: var(--text-primary);
}

[data-theme="dark"] code {
  background: rgba(255, 255, 255, 0.08);
  color: #93c5fd;
}

/* Reset code blocks that manage their own styling */
pre code,
.code-example-block pre code,
.solution-box code,
.output-block code,
.terminal-screen-pre code {
  background: transparent !important;
  color: inherit !important;
  padding: 0 !important;
  font-size: inherit !important;
  border-radius: 0 !important;
}

.mistake-box code {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  background: rgba(0, 0, 0, 0.06);
  padding: 0.15rem 0.35rem;
  border-radius: 4px;
  display: inline-block;
  margin: 0.25rem 0;
}

[data-theme="dark"] .mistake-box {
  color: #0f172a;
}

[data-theme="dark"] .mistake-box p {
  color: #0f172a;
}

[data-theme="dark"] .mistake-box p[style*="color"],
[data-theme="dark"] .mistake-box p[style*="--text-muted"] {
  color: #475569 !important;
}

[data-theme="dark"] .mistake-box strong {
  color: #0f172a;
  font-weight: 700;
}

[data-theme="dark"] .mistake-box em {
  color: #334155;
}

[data-theme="dark"] .mistake-box code {
  color: #0f172a !important;
  background: rgba(0, 0, 0, 0.07) !important;
}

[data-theme="dark"] .mistake-box pre {
  color: #0f172a;
}

[data-theme="dark"] .mistake-box ul,
[data-theme="dark"] .mistake-box ol,
[data-theme="dark"] .mistake-box li {
  color: #0f172a;
}

/* Comprehension Check Box */
.check-box {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin: 1.5rem 0;
}

.check-box-title {
  font-weight: 700;
  color: var(--brand-primary);
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

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

.check-box-answer {
  margin-top: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px dashed var(--border-color);
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Guided Lab Box */
.guided-lab-box {
  background: var(--brand-light);
  border: 1px solid rgba(59, 130, 246, 0.2);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-bottom: 2rem;
}

[data-theme="dark"] .guided-lab-box {
  background: rgba(30, 58, 138, 0.3);
}

.guided-lab-box h3 {
  font-size: 1.15rem;
  color: var(--brand-primary);
  margin-bottom: 0.75rem;
}

.guided-steps {
  margin-left: 1.5rem;
  color: var(--text-secondary);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

/* Exercise Tabs Bar */
.exercise-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  border-bottom: 2px solid var(--border-color);
  padding-bottom: 0.5rem;
}

.ex-tab-btn {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.ex-tab-btn:hover {
  background: var(--border-color);
  color: var(--text-primary);
}

.ex-tab-btn.active {
  background: var(--brand-primary);
  color: white;
  border-color: var(--brand-primary);
}

/* Code Editor Suite */
.editor-container {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--bg-card);
  margin-bottom: 1.5rem;
}

.editor-header {
  background: var(--bg-tertiary);
  padding: 0.85rem 1.25rem;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.editor-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.code-area {
  position: relative;
  min-height: 220px;
}

textarea.python-editor {
  width: 100%;
  min-height: 220px;
  padding: 1rem;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  line-height: 1.5;
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
  border: none;
  resize: vertical;
  outline: none;
}

.CodeMirror {
  height: 260px !important;
  font-family: var(--font-mono) !important;
  font-size: 0.95rem !important;
}

/* Action Toolbar */
.action-toolbar {
  padding: 1rem 1.25rem;
  background: var(--bg-card);
  border-top: 1px solid var(--border-color);
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

.btn {
  padding: 0.6rem 1.2rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  border: 1px solid transparent;
  transition: var(--transition);
}

.btn-primary {
  background: var(--brand-primary);
  color: white;
}

.btn-primary:hover {
  background: var(--brand-primary-hover);
}

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

.btn-success:hover {
  background: #15803d;
}

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

.btn-secondary:hover {
  background: var(--border-color);
}

.btn-warning {
  background: var(--warning-light);
  color: var(--warning);
  border-color: rgba(217, 119, 6, 0.3);
}

[data-theme="dark"] .btn-warning {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
  border-color: rgba(245, 158, 11, 0.35);
}

[data-theme="dark"] .btn-warning:hover {
  background: rgba(245, 158, 11, 0.25);
  color: #fef3c7;
}

/* Interactive Terminal Styling */
.terminal-container {
  background: #090d16;
  border: 1px solid #1e293b;
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-top: 1.5rem;
  margin-bottom: 1.5rem;
  font-family: var(--font-mono);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
}

.terminal-header {
  background: #111827;
  padding: 0.6rem 1rem;
  font-size: 0.82rem;
  font-weight: 700;
  color: #cbd5e1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid #1f2937;
}

.terminal-status-tag {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.15rem 0.6rem;
  border-radius: var(--radius-full);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: var(--transition);
}

.status-ready {
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.status-running {
  background: rgba(59, 130, 246, 0.15);
  color: #60a5fa;
  border: 1px solid rgba(59, 130, 246, 0.3);
}

.status-waiting {
  background: rgba(245, 158, 11, 0.2);
  color: #fbbf24;
  border: 1px solid rgba(245, 158, 11, 0.4);
  animation: pulse-waiting 1.5s infinite;
}

.status-stopped {
  background: rgba(148, 163, 184, 0.15);
  color: #94a3b8;
  border: 1px solid rgba(148, 163, 184, 0.3);
}

.status-error {
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
  border: 1px solid rgba(239, 68, 68, 0.3);
}

@keyframes pulse-waiting {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.65; }
}

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

.terminal-dot.red { background: #ef4444; }
.terminal-dot.yellow { background: #f59e0b; }
.terminal-dot.green { background: #10b981; }

.terminal-body {
  position: relative;
  min-height: 190px;
  max-height: 320px;
  padding: 1rem 1.25rem;
  overflow-y: auto;
  font-size: 0.92rem;
  color: #34d399;
  line-height: 1.6;
  outline: none;
  cursor: text;
  user-select: text;
}

.terminal-body:focus {
  background: #0b1120;
}

.terminal-screen-pre {
  margin: 0;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 0.92rem;
  line-height: 1.6;
  white-space: pre-wrap;
  word-break: break-all;
  color: #34d399;
  font-variant-ligatures: none;
}

.terminal-hidden-capture {
  position: absolute;
  top: 0;
  left: 0;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
  border: none;
  outline: none;
  padding: 0;
  margin: 0;
  resize: none;
}

.terminal-output-text {
  color: #34d399;
}

.terminal-err-text {
  color: #f87171;
  font-weight: 500;
}

.terminal-user-input-text {
  color: #38bdf8;
  font-weight: 700;
}

.terminal-active-chars {
  color: #38bdf8;
  font-weight: 700;
}

.terminal-cursor-indicator {
  display: inline-block;
  color: #38bdf8;
  font-weight: 700;
  animation: terminal-blink 1s step-start infinite;
  margin-left: 1px;
}

@keyframes terminal-blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

/* Test Results & Feedback */
.test-results-panel {
  margin-top: 1.25rem;
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius-md);
  animation: fadeIn 0.25s ease-in-out;
}

.test-results-panel.passed {
  background: var(--success-light);
  border: 1px solid rgba(22, 163, 74, 0.3);
  border-left: 5px solid var(--success);
}

.test-results-panel.failed {
  background: var(--danger-light);
  border: 1px solid rgba(220, 38, 38, 0.3);
  border-left: 5px solid var(--danger);
}

[data-theme="dark"] .test-results-panel {
  color: #0f172a;
}

[data-theme="dark"] .test-results-panel .feedback-item-label {
  color: #0f172a;
  font-weight: 700;
}

[data-theme="dark"] .test-results-panel .feedback-item-value {
  color: #334155;
}

[data-theme="dark"] .test-results-panel .feedback-item-code {
  color: #0f172a !important;
  background: rgba(0, 0, 0, 0.06) !important;
  border: 1px solid rgba(0, 0, 0, 0.12) !important;
  padding: 0.45rem 0.75rem !important;
}

[data-theme="dark"] .test-results-panel code {
  color: #0f172a !important;
  background: rgba(0, 0, 0, 0.07) !important;
}

[data-theme="dark"] .test-results-panel .feedback-tip {
  color: #0f172a;
}

.feedback-success-banner {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--success);
}

.feedback-success-icon {
  font-size: 1.35rem;
  line-height: 1;
}

.feedback-error-container {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.feedback-error-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--danger);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.feedback-item {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  font-size: 0.92rem;
}

.feedback-item-label {
  font-weight: 700;
  color: var(--text-primary);
  font-size: 0.92rem;
}

.feedback-item-value {
  color: var(--text-secondary);
  font-size: 0.92rem;
}

.feedback-item-code {
  font-family: var(--font-mono);
  background: rgba(0, 0, 0, 0.05);
  border: 1px solid var(--border-color);
  padding: 0.45rem 0.75rem;
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.88rem;
  white-space: pre-wrap;
  margin: 0;
  display: block;
}

.feedback-tip {
  margin-top: 0.35rem;
  padding: 0.65rem 0.9rem;
  background: var(--warning-light);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.88rem;
  line-height: 1.45;
  border-left: 3px solid var(--warning);
}

[data-theme="dark"] .feedback-tip {
  color: #0f172a;
}

[data-theme="dark"] .feedback-tip strong {
  color: #0f172a;
  font-weight: 700;
}

[data-theme="dark"] .feedback-tip code {
  color: #0f172a !important;
  background: rgba(0, 0, 0, 0.07) !important;
}

/* Hints & Solution */
.hints-container {
  margin-top: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.hint-box {
  background: var(--warning-light);
  border: 1px solid rgba(217, 119, 6, 0.2);
  border-radius: var(--radius-sm);
  padding: 1rem;
  font-size: 0.9rem;
}

[data-theme="dark"] .hint-box {
  color: #0f172a;
}

[data-theme="dark"] .hint-box p,
[data-theme="dark"] .hint-box ul,
[data-theme="dark"] .hint-box ol,
[data-theme="dark"] .hint-box li {
  color: #0f172a;
}

[data-theme="dark"] .hint-box strong {
  color: #0f172a;
  font-weight: 700;
}

[data-theme="dark"] .hint-box code {
  color: #0f172a !important;
  background: rgba(0, 0, 0, 0.07) !important;
}

.solution-box {
  background: #0f172a;
  color: #f8fafc;
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin-top: 1rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  white-space: pre-wrap;
}

/* Footer Module Navigation */
.module-nav-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-color);
}

/* Modal Confirmation */
.modal-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  opacity: 0;
  pointer-events: none;
  transition: var(--transition);
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  max-width: 480px;
  width: 90%;
  box-shadow: var(--shadow-lg);
}

.modal-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

@media (max-width: 992px) {
  .sidebar {
    position: fixed;
    transform: translateX(-100%);
  }
  .sidebar.mobile-open {
    transform: translateX(0);
  }
  .mobile-nav-toggle {
    display: block;
  }
  .main-content {
    padding: 1.5rem;
  }
}

/* Progressive Hint Accordion for Seminars & Practice */
.hint-accordion {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 0.85rem;
  overflow: hidden;
  transition: var(--transition);
}

.hint-accordion summary {
  padding: 0.9rem 1.2rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--brand-primary);
  user-select: none;
  list-style: none;
}

.hint-accordion summary::-webkit-details-marker {
  display: none;
}

.hint-accordion summary::after {
  content: '▼';
  margin-left: auto;
  font-size: 0.75rem;
  transition: transform 0.2s ease;
}

.hint-accordion[open] summary::after {
  transform: rotate(180deg);
}

.hint-accordion .hint-content {
  padding: 1rem 1.2rem;
  border-top: 1px solid var(--border-color);
  background: var(--bg-card);
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.hint-accordion[open] {
  border-color: var(--brand-primary);
  box-shadow: var(--shadow-sm);
}

/* Rubric and Requirements Tables */
.rubric-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0 1.5rem 0;
  font-size: 0.92rem;
}

.rubric-table th {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  font-weight: 700;
  text-align: left;
  padding: 0.85rem 1rem;
  border-bottom: 2px solid var(--border-color);
}

.rubric-table td {
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-secondary);
}

.rubric-table tr:hover td {
  background: rgba(0, 0, 0, 0.015);
}

[data-theme="dark"] .rubric-table tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

.rubric-table .total-row td {
  font-weight: 700;
  color: var(--brand-primary);
  background: var(--bg-tertiary);
  border-top: 2px solid var(--brand-primary);
}

body, pre, code, kbd, samp, var {
    font-variant-ligatures: no-common-ligatures !important;
    font-feature-settings: "liga" off, "calt" off, "clig" off, "dlig" off !important;
}