/* ====================================
   LYXXIS COURSES - HTML COURSE
   Main Stylesheet
   ==================================== */

:root {
  --primary-color: #2563eb;
  --secondary-color: #7c3aed;
  --accent-color: #f59e0b;
  --dark-bg: #0f172a;
  --light-bg: #f8fafc;
  --text-dark: #1e293b;
  --text-light: #64748b;
  --border-color: #e2e8f0;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --danger-color: #ef4444;
  --transition: all 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: var(--text-dark);
  background-color: var(--light-bg);
}

/* ====================================
   HEADER & NAVIGATION
   ==================================== */

header {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  color: white;
  padding: 1rem 0;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.8rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-decoration: none;
  color: white;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo:hover {
  opacity: 0.9;
}

nav {
  display: flex;
  gap: 2rem;
  align-items: center;
}

nav a {
  color: white;
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
  padding: 0.5rem 1rem;
  border-radius: 4px;
}

nav a:hover {
  background-color: rgba(255, 255, 255, 0.1);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: white;
  font-size: 1.5rem;
  cursor: pointer;
}

@media (max-width: 768px) {
  nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--primary-color);
    padding: 1rem;
    gap: 0;
  }

  nav.active {
    display: flex;
  }

  .mobile-menu-btn {
    display: block;
  }

  nav a {
    padding: 1rem;
    border-radius: 0;
  }
}

/* ====================================
   MAIN CONTAINER & LAYOUT
   ==================================== */

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

.main-content {
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: 2rem;
  margin: 2rem 0;
  min-height: 60vh;
}

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

  .sidebar {
    order: 2;
  }

  .content {
    order: 1;
  }
}

/* ====================================
   SIDEBAR & NAVIGATION
   ==================================== */

.sidebar {
  background: white;
  border-radius: 8px;
  padding: 1.5rem;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  height: fit-content;
  position: sticky;
  top: 100px;
}

.sidebar h3 {
  color: var(--primary-color);
  margin-bottom: 1rem;
  font-size: 1.1rem;
}

.chapter-list {
  list-style: none;
}

.chapter-item {
  margin-bottom: 0.5rem;
}

.chapter-item a {
  display: block;
  padding: 0.75rem 1rem;
  color: var(--text-dark);
  text-decoration: none;
  border-radius: 4px;
  transition: var(--transition);
  border-left: 3px solid transparent;
}

.chapter-item a:hover,
.chapter-item a.active {
  background-color: var(--light-bg);
  border-left-color: var(--primary-color);
  color: var(--primary-color);
  padding-left: 0.75rem;
}

/* ====================================
   MAIN CONTENT AREA
   ==================================== */

.content {
  background: white;
  border-radius: 8px;
  padding: 2rem;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.content h1 {
  color: var(--primary-color);
  margin-bottom: 0.5rem;
  font-size: 2.5rem;
}

.content h2 {
  color: var(--secondary-color);
  margin-top: 2rem;
  margin-bottom: 1rem;
  font-size: 1.8rem;
  border-bottom: 2px solid var(--border-color);
  padding-bottom: 0.5rem;
}

.content h3 {
  color: var(--text-dark);
  margin-top: 1.5rem;
  margin-bottom: 0.75rem;
  font-size: 1.3rem;
}

.breadcrumb {
  color: var(--text-light);
  font-size: 0.9rem;
  margin-bottom: 1.5rem;
}

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

.breadcrumb a:hover {
  text-decoration: underline;
}

.lesson-meta {
  display: flex;
  gap: 2rem;
  margin-bottom: 2rem;
  padding: 1rem;
  background-color: var(--light-bg);
  border-radius: 6px;
  border-left: 4px solid var(--primary-color);
}

.meta-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
}

.meta-item strong {
  color: var(--primary-color);
}

/* ====================================
   CODE BLOCKS
   ==================================== */

code {
  background-color: #f5f5f5;
  padding: 0.2rem 0.4rem;
  border-radius: 3px;
  font-family: 'Courier New', monospace;
  font-size: 0.9em;
  color: var(--danger-color);
}

pre {
  background-color: var(--text-dark);
  color: #e0e0e0;
  padding: 1.5rem;
  border-radius: 8px;
  overflow-x: auto;
  margin: 1.5rem 0;
  line-height: 1.5;
  font-family: 'Courier New', monospace;
}

pre code {
  background-color: transparent;
  padding: 0;
  color: inherit;
  font-size: 0.95em;
}

.code-label {
  color: var(--text-light);
  font-size: 0.8rem;
  margin-top: -1.5rem;
  margin-bottom: 0.5rem;
  padding: 0 1.5rem;
  font-weight: 600;
}

/* ====================================
   BOXES & HIGHLIGHTS
   ==================================== */

.info-box,
.tip-box,
.warning-box,
.example-box,
.practice-box {
  padding: 1.5rem;
  border-radius: 6px;
  margin: 1.5rem 0;
  border-left: 4px solid;
}

.info-box {
  background-color: #e0f2fe;
  border-left-color: var(--primary-color);
}

.info-box strong {
  color: var(--primary-color);
}

.tip-box {
  background-color: #dcfce7;
  border-left-color: var(--success-color);
}

.tip-box strong {
  color: var(--success-color);
}

.warning-box {
  background-color: #fef08a;
  border-left-color: var(--warning-color);
}

.warning-box strong {
  color: var(--warning-color);
}

.example-box {
  background-color: #f5f3ff;
  border-left-color: var(--secondary-color);
}

.example-box strong {
  color: var(--secondary-color);
}

.practice-box {
  background-color: #fce7f3;
  border-left-color: var(--danger-color);
}

.practice-box strong {
  color: var(--danger-color);
}

/* ====================================
   TABLES
   ==================================== */

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

th {
  background-color: var(--primary-color);
  color: white;
  padding: 1rem;
  text-align: left;
  font-weight: 600;
}

td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border-color);
}

tr:nth-child(even) {
  background-color: var(--light-bg);
}

tr:hover {
  background-color: #e0f2fe;
}

/* ====================================
   LISTS
   ==================================== */

ul, ol {
  margin-left: 1.5rem;
  margin-bottom: 1rem;
}

li {
  margin-bottom: 0.5rem;
}

/* ====================================
   BUTTONS
   ==================================== */

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
  transition: var(--transition);
  border: none;
  cursor: pointer;
  font-size: 1rem;
}

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

.btn-primary:hover {
  background-color: #1d4ed8;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

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

.btn-secondary:hover {
  background-color: #6d28d9;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(124, 58, 237, 0.3);
}

.btn-outline {
  background-color: transparent;
  color: var(--primary-color);
  border: 2px solid var(--primary-color);
}

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

/* ====================================
   NAVIGATION BUTTONS
   ==================================== */

.nav-buttons {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 2px solid var(--border-color);
}

.nav-buttons .btn {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-buttons a.btn {
  font-size: 0.95rem;
}

.progress-indicator {
  text-align: center;
  color: var(--text-light);
  font-size: 0.9rem;
}

/* ====================================
   HERO SECTION (Homepage)
   ==================================== */

.hero {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  color: white;
  padding: 4rem 2rem;
  border-radius: 8px;
  margin-bottom: 3rem;
  text-align: center;
}

.hero h1 {
  font-size: 3rem;
  margin-bottom: 1rem;
  color: white;
}

.hero p {
  font-size: 1.2rem;
  margin-bottom: 2rem;
  opacity: 0.9;
}

.hero .btn {
  display: inline-block;
  margin: 0 0.5rem;
}

/* ====================================
   CHAPTER GRID
   ==================================== */

.chapters-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.chapter-card {
  background: white;
  border-radius: 8px;
  padding: 1.5rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  transition: var(--transition);
  border-top: 4px solid var(--primary-color);
  display: flex;
  flex-direction: column;
}

.chapter-card:hover {
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);
  transform: translateY(-4px);
}

.chapter-card h3 {
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

.chapter-card p {
  color: var(--text-light);
  margin-bottom: 1rem;
  flex-grow: 1;
}

.chapter-card .badge {
  display: inline-block;
  background-color: var(--light-bg);
  color: var(--text-dark);
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.8rem;
  margin-bottom: 1rem;
}

.chapter-card .badge.beginner {
  background-color: #dcfce7;
  color: var(--success-color);
}

.chapter-card .badge.intermediate {
  background-color: #fef08a;
  color: var(--warning-color);
}

.chapter-card .badge.advanced {
  background-color: #fce7f3;
  color: var(--danger-color);
}

/* ====================================
   FOOTER
   ==================================== */

footer {
  background-color: var(--text-dark);
  color: white;
  padding: 2rem;
  margin-top: 4rem;
  text-align: center;
}

footer p {
  opacity: 0.8;
}

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

footer a:hover {
  text-decoration: underline;
}

/* ====================================
   PRINT STYLES
   ==================================== */

@media print {
  header,
  nav,
  .sidebar,
  .nav-buttons,
  .mobile-menu-btn,
  .lesson-meta {
    display: none;
  }

  body {
    background-color: white;
  }

  .main-content {
    grid-template-columns: 1fr;
    margin: 0;
  }

  .content {
    box-shadow: none;
    padding: 0;
  }

  code {
    background-color: #f5f5f5;
    padding: 0.2rem 0.4rem;
  }

  pre {
    background-color: #f5f5f5;
    color: var(--text-dark);
    border: 1px solid var(--border-color);
  }

  a {
    text-decoration: none;
  }

  page-break-inside: avoid;

  h1, h2, h3 {
    page-break-after: avoid;
  }

  table {
    page-break-inside: avoid;
  }
}

/* ====================================
   RESPONSIVE DESIGN
   ==================================== */

@media (max-width: 768px) {
  .hero h1 {
    font-size: 2rem;
  }

  .content {
    padding: 1.5rem;
  }

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

  .nav-buttons {
    flex-direction: column;
    gap: 1rem;
  }

  .nav-buttons .btn {
    width: 100%;
    justify-content: center;
  }
}

/* ====================================
   UTILITIES
   ==================================== */

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.text-center { text-align: center; }
.text-right { text-align: right; }
.text-left { text-align: left; }

.text-muted { color: var(--text-light); }
.text-primary { color: var(--primary-color); }
.text-secondary { color: var(--secondary-color); }