/* ========================================
   GameBoxOne Math - Main Stylesheet
   Mobile-First Responsive Design
   ======================================== */

/* === CSS Variables === */
:root {
  /* Colors - Warm & Fresh Theme */
  --primary: #FF6B6B;
  --primary-dark: #EE5A5A;
  --secondary: #4ECDC4;
  --secondary-dark: #3DBDB5;
  --accent: #3498DB;
  --accent-dark: #2980B9;
  
  /* Background Colors */
  --bg-primary: #FFF9F0;
  --bg-secondary: #FAF3E8;
  --bg-white: #FFFFFF;
  
  /* Text Colors */
  --text-primary: #2C3E50;
  --text-secondary: #34495E;
  --text-light: #7F8C8D;
  --text-white: #FFFFFF;
  
  /* Border & Shadow */
  --border-light: #E8E8E8;
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.1);
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  
  /* Font Sizes */
  --font-xs: 0.75rem;
  --font-sm: 0.875rem;
  --font-base: 1rem;
  --font-md: 1.125rem;
  --font-lg: 1.25rem;
  --font-xl: 1.5rem;
  --font-2xl: 2rem;
  --font-3xl: 2.5rem;
  --font-4xl: 3rem;
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* === Reset & Base === */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* === Typography === */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
}

h1 { font-size: var(--font-2xl); }
h2 { font-size: var(--font-xl); }
h3 { font-size: var(--font-lg); }
h4 { font-size: var(--font-md); }

p {
  margin-bottom: var(--spacing-sm);
  color: var(--text-secondary);
}

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

a:hover {
  color: var(--primary-dark);
}

/* === Container === */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* === Header & Navigation === */
.header {
  background: var(--bg-white);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) 0;
  min-height: 60px;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: var(--font-xl);
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
}

.logo-icon {
  width: 40px;
  height: 40px;
}

.nav-toggle {
  display: block;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
  min-width: 48px;
  min-height: 48px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 3px;
  background: var(--text-primary);
  margin: 5px 0;
  transition: var(--transition-base);
  border-radius: var(--radius-sm);
}

.nav-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--bg-white);
  box-shadow: var(--shadow-md);
  padding: var(--spacing-sm);
}

.nav-menu.active {
  display: block;
}

.nav-links {
  list-style: none;
}

.nav-links li {
  margin-bottom: var(--spacing-xs);
}

.nav-links a {
  display: block;
  padding: var(--spacing-sm);
  color: var(--text-secondary);
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: var(--transition-fast);
  min-height: 48px;
  display: flex;
  align-items: center;
}

.nav-links a:hover {
  background: var(--bg-secondary);
  color: var(--primary);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: 12px 24px;
  border: none;
  border-radius: var(--radius-md);
  font-size: var(--font-base);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-base);
  min-height: 48px;
  min-width: 48px;
  text-align: center;
}

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

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
  background: var(--secondary-dark);
  transform: translateY(-2px);
}

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

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

.btn-full {
  width: 100%;
}

/* === Hero Section === */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: var(--text-white);
  padding: var(--spacing-xl) 0;
  text-align: center;
}

.hero-title {
  font-size: var(--font-2xl);
  font-weight: 800;
  margin-bottom: var(--spacing-md);
  color: var(--text-white);
}

.hero-subtitle {
  font-size: var(--font-md);
  margin-bottom: var(--spacing-lg);
  color: rgba(255, 255, 255, 0.95);
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

/* === Section Styles === */
.section {
  padding: var(--spacing-xl) 0;
}

.section-title {
  text-align: center;
  font-size: var(--font-xl);
  margin-bottom: var(--spacing-lg);
}

.section-subtitle {
  text-align: center;
  font-size: var(--font-md);
  color: var(--text-light);
  margin-bottom: var(--spacing-lg);
}

/* === Feature Cards === */
.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
}

.feature-card {
  background: var(--bg-white);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.feature-icon {
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-md);
  font-size: var(--font-2xl);
}

.feature-title {
  font-size: var(--font-lg);
  margin-bottom: var(--spacing-sm);
}

.feature-description {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* === Course Cards === */
.courses-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
}

.course-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
}

.course-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.course-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.course-content {
  padding: var(--spacing-md);
}

.course-title {
  font-size: var(--font-lg);
  margin-bottom: var(--spacing-xs);
}

.course-level {
  display: inline-block;
  padding: 4px 12px;
  background: var(--secondary);
  color: var(--text-white);
  border-radius: var(--radius-sm);
  font-size: var(--font-sm);
  margin-bottom: var(--spacing-sm);
}

.course-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: var(--spacing-sm);
  padding-top: var(--spacing-sm);
  border-top: 1px solid var(--border-light);
}

/* === Blog Cards === */
.blog-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
}

.blog-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
}

.blog-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.blog-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.blog-content {
  padding: var(--spacing-md);
}

.blog-title {
  font-size: var(--font-lg);
  margin-bottom: var(--spacing-xs);
}

.blog-excerpt {
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: var(--spacing-sm);
}

.blog-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--font-sm);
  color: var(--text-light);
  padding-top: var(--spacing-sm);
  border-top: 1px solid var(--border-light);
}

.blog-tags {
  display: flex;
  gap: var(--spacing-xs);
  flex-wrap: wrap;
  margin-top: var(--spacing-xs);
}

.blog-tag {
  padding: 4px 8px;
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  font-size: var(--font-xs);
}

/* === Pagination === */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--spacing-xs);
  margin-top: var(--spacing-lg);
  flex-wrap: wrap;
}

.pagination-btn {
  padding: 12px 16px;
  min-width: 48px;
  min-height: 48px;
  border: 2px solid var(--border-light);
  background: var(--bg-white);
  color: var(--text-secondary);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-weight: 600;
}

.pagination-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.pagination-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: var(--text-white);
}

.pagination-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* === Footer === */
.footer {
  background: var(--text-primary);
  color: var(--text-white);
  padding: var(--spacing-xl) 0 var(--spacing-lg);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.footer-title {
  font-size: var(--font-lg);
  margin-bottom: var(--spacing-md);
  color: var(--text-white);
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: var(--spacing-xs);
}

.footer-links a {
  color: rgba(255, 255, 255, 0.8);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--primary);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--spacing-lg);
  text-align: center;
  color: rgba(255, 255, 255, 0.9);
}

.footer-bottom p {
  color: rgba(255, 255, 255, 0.9);
}

.footer-developer {
  margin-top: var(--spacing-xs);
  font-size: var(--font-sm);
  color: rgba(255, 255, 255, 0.9);
}

/* === Cookie Banner === */
.cookie-banner {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--bg-white);
  box-shadow: var(--shadow-lg);
  padding: var(--spacing-md);
  z-index: 9999;
  display: none;
}

.cookie-banner.show {
  display: block;
}

.cookie-content {
  max-width: 1200px;
  margin: 0 auto;
}

.cookie-text {
  margin-bottom: var(--spacing-sm);
  line-height: 1.6;
}

.cookie-actions {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

/* === Comments Section === */
.comments-section {
  margin-top: var(--spacing-xl);
  padding-top: var(--spacing-lg);
  border-top: 2px solid var(--border-light);
}

.comment {
  background: var(--bg-white);
  padding: var(--spacing-md);
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-md);
  box-shadow: var(--shadow-sm);
}

.comment-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
}

.comment-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-white);
  font-weight: 700;
  font-size: var(--font-lg);
}

.comment-author {
  font-weight: 600;
  color: var(--text-primary);
}

.comment-date {
  font-size: var(--font-sm);
  color: var(--text-light);
}

.comment-rating {
  color: #FFA500;
  margin-bottom: var(--spacing-xs);
}

.comment-text {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* === FAQ Section === */
.faq-item {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-md);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}

.faq-question {
  padding: var(--spacing-md);
  cursor: pointer;
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: 60px;
}

.faq-answer {
  padding: 0 var(--spacing-md) var(--spacing-md);
  color: var(--text-secondary);
  line-height: 1.6;
  display: none;
}

.faq-item.active .faq-answer {
  display: block;
}

/* === Progress Bar === */
.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--bg-secondary);
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin: var(--spacing-sm) 0;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  transition: width var(--transition-slow);
}

/* === Utility Classes === */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.hidden { display: none; }
.visible { display: block; }

/* === Responsive - Tablet === */
@media (min-width: 768px) {
  h1 { font-size: var(--font-3xl); }
  h2 { font-size: var(--font-2xl); }
  
  .hero {
    padding: var(--spacing-xl) 0;
  }
  
  .hero-title {
    font-size: var(--font-3xl);
  }
  
  .hero-subtitle {
    font-size: var(--font-lg);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
  }
  
  .hero-actions {
    flex-direction: row;
    justify-content: center;
  }
  
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .courses-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .blog-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .cookie-actions {
    flex-direction: row;
    justify-content: flex-end;
  }
}

/* === Responsive - Desktop === */
@media (min-width: 1024px) {
  .nav-toggle {
    display: none;
  }
  
  .nav-menu {
    display: block !important;
    position: static;
    box-shadow: none;
    padding: 0;
    background: transparent;
  }
  
  .nav-links {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
  }
  
  .nav-links li {
    margin-bottom: 0;
  }
  
  .nav-links a {
    padding: var(--spacing-xs) var(--spacing-sm);
    min-height: auto;
  }
  
  .features-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  
  .courses-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  
  .blog-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  
  .footer-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  
  .section {
    padding: var(--spacing-xl) 0;
  }
}

/* === Accessibility === */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* Focus visible */
*:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* === Print Styles === */
@media print {
  .header, .footer, .cookie-banner, .btn {
    display: none !important;
  }
  
  body {
    font-size: 12pt;
    line-height: 1.5;
  }
}