/* ============================================
   AGRILIT HUB - Modern Agriculture Library
   Main Stylesheet
   ============================================ */

/* CSS Variables */
:root {
  /* Primary Colors - Navy Blue */
  --primary-dark: #0a1628;
  --primary: #1e3a5f;
  --primary-light: #2d5a87;
  --primary-lighter: #4a7fb5;
  
  /* Secondary Colors */
  --white: #ffffff;
  --gray-50: #f8fafc;
  --gray-100: #f1f5f9;
  --gray-200: #e2e8f0;
  --gray-300: #cbd5e1;
  --gray-400: #94a3b8;
  --gray-500: #64748b;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-800: #1e293b;
  --gray-900: #0f172a;
  
  /* Accent Colors */
  --accent-green: #10b981;
  --accent-orange: #f59e0b;
  --accent-red: #ef4444;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  /* Border Radius */
  --radius-sm: 6px;
  --radius: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition: 0.3s ease;
  --transition-slow: 0.5s ease;
  
  /* Typography */
  --font-sans: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--gray-800);
  background-color: var(--gray-50);
  min-height: 100vh;
}

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

img {
  max-width: 100%;
  height: auto;
  display: block;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea {
  font-family: inherit;
  font-size: inherit;
}

/* ============================================
   UTILITY CLASSES
   ============================================ */

.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 5rem 0;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--primary-dark);
  text-align: center;
  margin-bottom: 3rem;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--gray-500);
  text-align: center;
  margin-top: -2rem;
  margin-bottom: 3rem;
}

/* Grid */
.grid {
  display: grid;
  gap: 1.5rem;
}

.grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

/* Flex */
.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

.gap-2 {
  gap: 0.5rem;
}

.gap-4 {
  gap: 1rem;
}

.gap-6 {
  gap: 1.5rem;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1.75rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius);
  transition: all var(--transition);
  cursor: pointer;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: var(--white);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

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

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

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

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

.btn-sm {
  padding: 0.625rem 1.25rem;
  font-size: 0.875rem;
}

.btn-lg {
  padding: 1rem 2.5rem;
  font-size: 1.125rem;
}

/* ============================================
   NAVBAR
   ============================================ */

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--gray-200);
  transition: all var(--transition);
}

.navbar.scrolled {
  box-shadow: var(--shadow-md);
}

.navbar-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.navbar-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 1.25rem;
}

.navbar-menu {
  display: flex;
  align-items: center;
  gap: 2.5rem;
}

.navbar-link {
  font-size: 1rem;
  font-weight: 500;
  color: var(--gray-600);
  position: relative;
  padding: 0.5rem 0;
}

.navbar-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--primary), var(--primary-light));
  transition: width var(--transition);
}

.navbar-link:hover {
  color: var(--primary);
}

.navbar-link:hover::after,
.navbar-link.active::after {
  width: 100%;
}

.navbar-link.active {
  color: var(--primary);
}

/* Mobile Menu Toggle */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 0.5rem;
}

.menu-toggle span {
  display: block;
  width: 25px;
  height: 3px;
  background: var(--primary);
  border-radius: 3px;
  transition: all var(--transition);
}

/* ============================================
   HERO SECTION
   ============================================ */

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 50%, var(--primary-light) 100%);
  position: relative;
  overflow: hidden;
  padding-top: 72px;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.5;
}

.hero-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-content {
  color: var(--white);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 1.5rem;
  animation: fadeInDown 0.6s ease;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 1.5rem;
  animation: fadeInUp 0.6s ease 0.1s both;
}

.hero-title span {
  background: linear-gradient(135deg, #60a5fa 0%, #34d399 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 2.5rem;
  max-width: 500px;
  animation: fadeInUp 0.6s ease 0.2s both;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  animation: fadeInUp 0.6s ease 0.3s both;
}

.hero-image {
  position: relative;
  animation: fadeInRight 0.8s ease 0.2s both;
}

.hero-image img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  transform: perspective(1000px) rotateY(-5deg);
  transition: transform var(--transition);
}

.hero-image:hover img {
  transform: perspective(1000px) rotateY(0deg);
}

/* Floating Elements Animation */
.floating-element {
  position: absolute;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border-radius: var(--radius);
  padding: 1rem;
  animation: float 6s ease-in-out infinite;
}

.floating-element-1 {
  top: 10%;
  right: -20px;
  animation-delay: 0s;
}

.floating-element-2 {
  bottom: 20%;
  left: -30px;
  animation-delay: 2s;
}

/* ============================================
   BOOK CARDS
   ============================================ */

.books-section {
  background: var(--gray-50);
  padding: 5rem 0;
}

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

.book-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: all var(--transition);
  cursor: pointer;
}

.book-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-xl);
}

.book-cover {
  position: relative;
  aspect-ratio: 3/4;
  overflow: hidden;
}

.book-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition);
}

.book-card:hover .book-cover img {
  transform: scale(1.05);
}

.book-badge {
  position: absolute;
  top: 1rem;
  left: 1rem;
  background: linear-gradient(135deg, var(--accent-green) 0%, #059669 100%);
  color: var(--white);
  padding: 0.375rem 0.875rem;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
}

.book-info {
  padding: 1.5rem;
}

.book-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--gray-800);
  margin-bottom: 0.5rem;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.book-author {
  font-size: 0.875rem;
  color: var(--gray-500);
  margin-bottom: 0.25rem;
}

.book-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--gray-100);
}

.book-year {
  font-size: 0.875rem;
  color: var(--gray-400);
}

.book-citation {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.875rem;
  color: var(--primary);
  font-weight: 500;
}

/* ============================================
   SEARCH BAR
   ============================================ */

.search-container {
  max-width: 600px;
  margin: 0 auto 3rem;
}

.search-box {
  position: relative;
  display: flex;
  align-items: center;
}

.search-input {
  width: 100%;
  padding: 1rem 1.5rem;
  padding-left: 3.5rem;
  font-size: 1rem;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-full);
  background: var(--white);
  transition: all var(--transition);
}

.search-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(30, 58, 95, 0.1);
}

.search-input::placeholder {
  color: var(--gray-400);
}

.search-icon {
  position: absolute;
  left: 1.25rem;
  color: var(--gray-400);
  font-size: 1.25rem;
}

.search-filters {
  display: flex;
  gap: 0.5rem;
  margin-top: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.filter-chip {
  padding: 0.5rem 1rem;
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  color: var(--gray-600);
  cursor: pointer;
  transition: all var(--transition);
}

.filter-chip:hover,
.filter-chip.active {
  background: var(--primary);
  color: var(--white);
  border-color: var(--primary);
}

/* ============================================
   READING PAGE - FLIP BOOK
   ============================================ */

.reading-page {
  min-height: 100vh;
  background: linear-gradient(135deg, var(--gray-100) 0%, var(--gray-200) 100%);
  padding-top: 72px;
}

.reading-header {
  background: var(--white);
  padding: 1rem 0;
  border-bottom: 1px solid var(--gray-200);
  position: sticky;
  top: 72px;
  z-index: 100;
}

.reading-header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.reading-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--gray-800);
}

.reading-controls {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.page-indicator {
  font-size: 0.875rem;
  color: var(--gray-500);
  background: var(--gray-100);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-full);
}

.reading-container {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: calc(100vh - 200px);
  padding: 2rem;
}

.book-container {
  perspective: 1500px;
  width: 100%;
  max-width: 900px;
}

.book {
  position: relative;
  width: 100%;
  aspect-ratio: 16/10;
  transform-style: preserve-3d;
}

.page {
  position: absolute;
  width: 50%;
  height: 100%;
  top: 0;
  background: var(--white);
  transform-origin: left center;
  transform-style: preserve-3d;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: var(--shadow-lg);
  border-radius: 0 var(--radius) var(--radius) 0;
  overflow: hidden;
}

.page-left {
  left: 0;
  border-radius: var(--radius) 0 0 var(--radius);
  background: linear-gradient(to right, #f8f9fa 0%, var(--white) 5%);
}

.page-right {
  left: 50%;
  border-radius: 0 var(--radius) var(--radius) 0;
  background: linear-gradient(to left, #f8f9fa 0%, var(--white) 5%);
}

.page.flipped {
  transform: rotateY(-180deg);
}

.page-content {
  padding: 2rem;
  height: 100%;
  overflow-y: auto;
}

.page-content h2 {
  font-size: 1.5rem;
  color: var(--primary);
  margin-bottom: 1rem;
}

.page-content p {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--gray-700);
  margin-bottom: 1rem;
  text-align: justify;
}

.page-number {
  position: absolute;
  bottom: 1rem;
  font-size: 0.875rem;
  color: var(--gray-400);
}

.page-left .page-number {
  right: 2rem;
}

.page-right .page-number {
  left: 2rem;
}

.navigation-buttons {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-top: 2rem;
  padding-bottom: 2rem;
}

.nav-btn {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 1.5rem;
  background: var(--white);
  border: 2px solid var(--primary);
  border-radius: var(--radius);
  color: var(--primary);
  font-weight: 600;
  transition: all var(--transition);
}

.nav-btn:hover:not(:disabled) {
  background: var(--primary);
  color: var(--white);
}

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

/* ============================================
   FORMS
   ============================================ */

.form-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
  padding: 2rem;
  padding-top: 100px;
}

.form-container {
  width: 100%;
  max-width: 480px;
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-xl);
}

.form-header {
  text-align: center;
  margin-bottom: 2rem;
}

.form-logo {
  width: 64px;
  height: 64px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
  color: var(--white);
  font-size: 2rem;
}

.form-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--gray-800);
  margin-bottom: 0.5rem;
}

.form-subtitle {
  font-size: 1rem;
  color: var(--gray-500);
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--gray-700);
  margin-bottom: 0.5rem;
}

.form-input {
  width: 100%;
  padding: 0.875rem 1rem;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius);
  font-size: 1rem;
  transition: all var(--transition);
  background: var(--gray-50);
}

.form-input:focus {
  outline: none;
  border-color: var(--primary);
  background: var(--white);
  box-shadow: 0 0 0 4px rgba(30, 58, 95, 0.1);
}

.form-input::placeholder {
  color: var(--gray-400);
}

textarea.form-input {
  min-height: 120px;
  resize: vertical;
}

.form-button {
  width: 100%;
  padding: 1rem;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: var(--white);
  border: none;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
}

.form-button:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.form-footer {
  text-align: center;
  margin-top: 1.5rem;
  font-size: 0.875rem;
  color: var(--gray-500);
}

.form-footer a {
  color: var(--primary);
  font-weight: 600;
}

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

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

.footer {
  background: var(--primary-dark);
  color: var(--white);
  padding: 4rem 0 2rem;
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand {
  max-width: 300px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.footer-description {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.875rem;
  line-height: 1.7;
}

.footer-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  color: var(--white);
}

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

.footer-links li {
  margin-bottom: 0.75rem;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.875rem;
  transition: color var(--transition);
}

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

.footer-social {
  display: flex;
  gap: 1rem;
}

.social-link {
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  transition: all var(--transition);
}

.social-link:hover {
  background: var(--primary-light);
  transform: translateY(-3px);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-copyright {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.6);
}

/* ============================================
   ANIMATIONS
   ============================================ */

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-20px);
  }
}

@keyframes pulse {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
}

/* Scroll Animation Classes */
.scroll-reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.6s ease;
}

.scroll-reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

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

@media (max-width: 1024px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .hero-content {
    order: 1;
  }
  
  .hero-image {
    order: 0;
    max-width: 500px;
    margin: 0 auto;
  }
  
  .hero-subtitle {
    margin-left: auto;
    margin-right: auto;
  }
  
  .hero-buttons {
    justify-content: center;
  }
  
  .footer-content {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .navbar-menu {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 2rem;
    gap: 1.5rem;
    border-bottom: 1px solid var(--gray-200);
    transform: translateY(-150%);
    transition: transform var(--transition);
  }
  
  .navbar-menu.active {
    transform: translateY(0);
  }
  
  .menu-toggle {
    display: flex;
  }
  
  .hero-title {
    font-size: 2.5rem;
  }
  
  .hero-subtitle {
    font-size: 1rem;
  }
  
  .section-title {
    font-size: 1.75rem;
  }
  
  .books-grid {
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 1.5rem;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
  
  .page {
    width: 100%;
    position: relative;
    left: 0;
    border-radius: var(--radius);
    margin-bottom: 1rem;
  }
  
  .book {
    aspect-ratio: auto;
  }
  
  .reading-container {
    padding: 1rem;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }
  
  .hero-buttons {
    flex-direction: column;
  }
  
  .btn {
    width: 100%;
  }
  
  .form-container {
    padding: 1.5rem;
  }
  
  .books-grid {
    grid-template-columns: 1fr;
  }
}

/* ============================================
   UTILITY
   ============================================ */

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

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

.mt-4 {
  margin-top: 1rem;
}

.mb-4 {
  margin-bottom: 1rem;
}

.hidden {
  display: none !important;
}