/* index.css - Custom Styling System for Interactive Python Platform */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@300;400;500;600;700;800&family=Fira+Code:wght@400;500&display=swap');

/* Default Theme variables (Dark Theme) */
:root {
  --bg-primary: #090d16;
  --bg-secondary: #111827;
  --bg-tertiary: #1f2937;
  --border-color: #374151;
  --text-primary: #f3f4f6;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  
  --accent-primary: #6366f1; /* Indigo */
  --accent-secondary: #06b6d4; /* Cyan */
  --accent-hover: #4f46e5;
  
  --color-success: #10b981; /* Emerald */
  --color-danger: #ef4444; /* Rose */
  --color-warning: #f59e0b; /* Amber */
  
  --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-heading: 'Outfit', sans-serif;
  --font-body: 'Inter', sans-serif;
  --font-mono: 'Fira Code', monospace;
  
  --transition-smooth: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Light Theme overrides */
body.light-theme {
  --bg-primary: #f9fafb;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f3f4f6;
  --border-color: #e5e7eb;
  --text-primary: #111827;
  --text-secondary: #4b5563;
  --text-muted: #9ca3af;
  
  --accent-primary: #4f46e5;
  --accent-secondary: #0891b2;
  --accent-hover: #3730a3;
  
  --color-success: #059669;
  --color-danger: #dc2626;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

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

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.3s, color 0.3s, border-color 0.3s;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.25;
}

body.light-theme h1, body.light-theme h2, body.light-theme h3, body.light-theme h4, body.light-theme h5, body.light-theme h6 {
  color: #000000;
}

a {
  color: var(--accent-secondary);
  text-decoration: none;
  transition: var(--transition-smooth);
}

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

/* Layout Containers */
.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

/* Header & Navbar */
header {
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-secondary);
  position: sticky;
  top: 0;
  z-index: 50;
  padding: 1rem 0;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.logo {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo span {
  font-size: 0.8rem;
  background: var(--bg-tertiary);
  color: var(--text-primary);
  padding: 0.2rem 0.6rem;
  border-radius: 9999px;
  border: 1px solid var(--border-color);
  -webkit-text-fill-color: initial;
}

/* Theme Switcher Button */
.theme-toggle {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 0.5rem 0.75rem;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 500;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: var(--transition-smooth);
}

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

/* Dashboard Elements */
.dashboard-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 2rem;
  margin-top: 2rem;
}

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

/* Cards & Glassmorphism */
.card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: var(--shadow-md);
  transition: var(--transition-smooth);
}

.card:hover {
  border-color: rgba(99, 102, 241, 0.4);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
}

.card-title {
  font-size: 1.25rem;
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Progress Rings and Stats */
.progress-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 1rem 0;
}

.progress-ring-wrapper {
  position: relative;
  width: 150px;
  height: 150px;
}

.progress-ring {
  transform: rotate(-90deg);
}

.progress-ring-circle-bg {
  fill: none;
  stroke: var(--bg-tertiary);
  stroke-width: 10;
}

.progress-ring-circle {
  fill: none;
  stroke: var(--accent-primary);
  stroke-width: 10;
  stroke-linecap: round;
  transition: stroke-dashoffset 0.35s;
  transform-origin: 50% 50%;
}

.progress-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--font-heading);
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text-primary);
}

.stats-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  width: 100%;
  margin-top: 1.5rem;
}

.stat-item {
  background: var(--bg-tertiary);
  border-radius: 8px;
  padding: 0.75rem;
  text-align: center;
}

.stat-value {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent-secondary);
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* Syllabus Timeline */
.timeline {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.timeline-module {
  border-left: 2px solid var(--border-color);
  padding-left: 1.5rem;
  margin-left: 0.75rem;
  position: relative;
}

.timeline-module::before {
  content: '';
  position: absolute;
  left: -7px;
  top: 0;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent-primary);
  box-shadow: 0 0 10px var(--accent-primary);
}

.module-header {
  margin-bottom: 1rem;
}

.module-tag {
  display: inline-block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: rgba(99, 102, 241, 0.15);
  color: var(--accent-primary);
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  margin-bottom: 0.25rem;
  font-weight: bold;
}

.lessons-list {
  display: grid;
  gap: 0.75rem;
}

.lesson-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  transition: var(--transition-smooth);
}

.lesson-row:hover {
  border-color: var(--accent-secondary);
  transform: translateX(4px);
}

.lesson-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-grow: 1;
}

.lesson-checkbox {
  appearance: none;
  width: 1.25rem;
  height: 1.25rem;
  border: 2px solid var(--border-color);
  border-radius: 4px;
  background: transparent;
  cursor: pointer;
  display: flex !important; /* Force flex display to override inline block styles */
  align-items: center;
  justify-content: center;
  transition: var(--transition-smooth);
}

.lesson-checkbox:checked {
  background: var(--color-success);
  border-color: var(--color-success);
}

.lesson-checkbox:checked::after {
  content: '✓';
  color: #ffffff;
  font-size: 0.8rem;
  font-weight: bold;
}

/* Sidebar progress status checkbox styling to keep it centered and looking nice */
#lesson-status-chk.lesson-checkbox {
  width: 2.5rem !important;
  height: 2.5rem !important;
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  margin: 0 auto !important;
}

#lesson-status-chk.lesson-checkbox:checked::after {
  font-size: 1.5rem !important;
}

.lesson-title {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-primary);
}

.lesson-meta {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Lesson Interface Styles with Tabs */
.lesson-layout {
  display: grid;
  grid-template-columns: 3fr 1fr;
  gap: 2rem;
}

@media (max-width: 900px) {
  .lesson-layout {
    grid-template-columns: 1fr;
  }
}

.lesson-content {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 2rem;
  box-shadow: var(--shadow-lg);
}

.lesson-meta-header {
  display: flex;
  gap: 0.75rem;
  align-items: center;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* Tabs Navigation */
.tabs-container {
  margin-top: 1.5rem;
}

.tab-buttons {
  display: flex;
  gap: 0.5rem;
  border-bottom: 2px solid var(--border-color);
  margin-bottom: 1.5rem;
  padding-bottom: 0.1rem;
  overflow-x: auto;
}

.tab-btn {
  background: transparent;
  color: var(--text-secondary);
  border: none;
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 600;
  padding: 0.75rem 1.25rem;
  cursor: pointer;
  border-radius: 8px 8px 0 0;
  border-bottom: 3px solid transparent;
  transition: var(--transition-smooth);
  white-space: nowrap;
}

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

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

.tab-content {
  display: none;
  animation: fadeIn 0.2s ease-in-out;
}

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

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(5px); }
  to { opacity: 1; transform: translateY(0); }
}

.lesson-body p {
  margin-bottom: 1.25rem;
  color: var(--text-secondary);
}

.lesson-body ul, .lesson-body ol {
  margin-left: 1.5rem;
  margin-bottom: 1.25rem;
  color: var(--text-secondary);
}

.lesson-body li {
  margin-bottom: 0.5rem;
}

.lesson-body h2 {
  font-size: 1.5rem;
  margin: 2rem 0 1rem 0;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5rem;
}

.lesson-body h3 {
  font-size: 1.2rem;
  margin: 1.5rem 0 0.75rem 0;
}

/* Callout Alerts (GitHub format) */
.alert {
  padding: 1rem;
  border-left: 4px solid;
  border-radius: 4px;
  background: var(--bg-tertiary);
  margin: 1.5rem 0;
}

.alert-note {
  border-color: var(--accent-primary);
}

.alert-tip {
  border-color: var(--accent-secondary);
}

.alert-warning {
  border-color: var(--color-warning);
}

.alert-title {
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.25rem;
  color: var(--text-primary);
}

/* Interactive Playground & Code Blocks */
pre {
  background: #0d1117;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1rem;
  overflow-x: auto;
  margin: 1rem 0;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  position: relative;
}

code {
  font-family: var(--font-mono);
  background: var(--bg-tertiary);
  padding: 0.15rem 0.35rem;
  border-radius: 4px;
  font-size: 0.85em;
  color: #f43f5e;
}

pre code {
  background: transparent;
  padding: 0;
  font-size: inherit;
  color: #e2e8f0;
}

body.light-theme code {
  color: #be123c;
  background: #f1f5f9;
}

.code-header {
  background: var(--bg-tertiary);
  border-top-left-radius: 8px;
  border-top-right-radius: 8px;
  padding: 0.5rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  border-bottom: none;
  margin-top: 1rem;
  margin-bottom: -1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Sandbox and output validation */
.playground-box {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.25rem;
  margin-bottom: 1.5rem;
}

.sandbox-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--accent-secondary);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.sandbox-console {
  background: #090d16;
  border: 1px solid #1f2937;
  border-radius: 6px;
  padding: 1rem;
  font-family: var(--font-mono);
  color: var(--color-success);
}

.sandbox-input-row {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.sandbox-input {
  flex-grow: 1;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  padding: 0.5rem;
  color: var(--text-primary);
  font-family: var(--font-mono);
  resize: vertical;
}

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

.btn {
  background: var(--accent-primary);
  color: #ffffff;
  border: none;
  padding: 0.5rem 1.25rem;
  border-radius: 4px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-smooth);
}

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

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

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

/* Quizzes (Desirable Difficulty Rules) */
.quiz-section {
  margin: 0;
}

.quiz-card {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.quiz-question {
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.quiz-options {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.5rem;
}

.quiz-option {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 0.75rem 1rem;
  cursor: pointer;
  transition: var(--transition-smooth);
  text-align: left;
  color: var(--text-primary);
  font-family: var(--font-body);
  width: 100%;
}

.quiz-option:hover {
  border-color: var(--accent-primary);
  background: rgba(99, 102, 241, 0.05);
}

/* Selected states */
.quiz-option.correct {
  background: rgba(16, 185, 129, 0.15) !important;
  border-color: var(--color-success) !important;
  color: var(--color-success) !important;
  font-weight: 600;
}

.quiz-option.incorrect {
  background: rgba(239, 68, 68, 0.15) !important;
  border-color: var(--color-danger) !important;
  color: var(--color-danger) !important;
}

.quiz-explanation {
  margin-top: 1rem;
  padding: 0.75rem;
  background: var(--bg-secondary);
  border-left: 3px solid var(--accent-secondary);
  border-radius: 4px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  display: none;
}

/* Floating Navigation Dock */
.navigation-dock {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 9999px;
  padding: 0.5rem 1.5rem;
  display: flex;
  gap: 1rem;
  align-items: center;
  box-shadow: var(--shadow-lg);
  z-index: 100;
}

.dock-btn {
  background: transparent;
  color: var(--text-secondary);
  border: none;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1rem;
  border-radius: 9999px;
  transition: var(--transition-smooth);
}

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

.dock-btn-primary {
  background: var(--accent-primary);
  color: #ffffff;
}

.dock-btn-primary:hover {
  background: var(--accent-hover);
  color: #ffffff;
}

.dock-divider {
  width: 1px;
  height: 1.5rem;
  background: var(--border-color);
}

/* Tables in Lesson Body */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
}

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

th {
  background: var(--bg-tertiary);
  font-weight: 600;
}

tr:nth-child(even) {
  background: rgba(31, 41, 55, 0.1);
}

body.light-theme tr:nth-child(even) {
  background: rgba(229, 231, 235, 0.3);
}

/* Cheat Sheet Quick Search */
.search-container {
  margin-bottom: 2rem;
}

.search-input {
  width: 100%;
  padding: 0.85rem 1.5rem;
  font-size: 1rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  color: var(--text-primary);
  transition: var(--transition-smooth);
}

.search-input:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 10px rgba(99, 102, 241, 0.2);
}

.cheatsheet-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

.syntax-item {
  margin-bottom: 1.5rem;
}

.syntax-item h3 {
  font-size: 1rem;
  margin-bottom: 0.5rem;
  color: var(--accent-secondary);
}

.syntax-example {
  background: #090d16;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: #f3f4f6;
  overflow-x: auto;
}

/* Visual elements for Lesson 1, Flowcharts */
.flowchart-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin: 1.5rem 0;
}

.flowchart-node {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 0.75rem 1.25rem;
  text-align: center;
  position: relative;
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

.flowchart-node::after {
  content: '↓';
  position: absolute;
  bottom: -20px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--accent-secondary);
  font-weight: bold;
}

.flowchart-node:last-child::after {
  display: none;
}