/* ============================================
   BOUKILIBRE - PREMIUM EBOOK STORE
   Design System & Core Styles
   ============================================ */

/* ============================================
   CSS VARIABLES - DESIGN TOKENS
   ============================================ */
:root {
  /* Color Palette - Premium Blue/Pink/Gray */
  --color-primary: #1a2f5a;
  --color-primary-light: #2d4a7c;
  --color-primary-dark: #0f1d3a;

  --color-accent: #f4a6b8;
  --color-accent-light: #ffc9d6;
  --color-accent-dark: #e8899d;

  --color-gray-900: #1a202c;
  --color-gray-800: #2d3748;
  --color-gray-700: #4a5568;
  --color-gray-600: #718096;
  --color-gray-500: #a0aec0;
  --color-gray-400: #cbd5e0;
  --color-gray-300: #e2e8f0;
  --color-gray-200: #edf2f7;
  --color-gray-100: #f7fafc;

  --color-white: #ffffff;
  --color-black: #000000;

  /* Semantic Colors */
  --color-success: #48bb78;
  --color-warning: #ed8936;
  --color-error: #f56565;
  --color-info: #4299e1;

  /* Typography */
  --font-heading: 'Playfair Display', serif;
  --font-body: 'Inter', sans-serif;

  --font-size-xs: 0.75rem;
  /* 12px */
  --font-size-sm: 0.875rem;
  /* 14px */
  --font-size-base: 1rem;
  /* 16px */
  --font-size-lg: 1.125rem;
  /* 18px */
  --font-size-xl: 1.25rem;
  /* 20px */
  --font-size-2xl: 1.5rem;
  /* 24px */
  --font-size-3xl: 1.875rem;
  /* 30px */
  --font-size-4xl: 2.25rem;
  /* 36px */
  --font-size-5xl: 3rem;
  /* 48px */
  --font-size-6xl: 3.75rem;
  /* 60px */

  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;

  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* Spacing Scale (8px base) */
  --space-1: 0.5rem;
  /* 8px */
  --space-2: 1rem;
  /* 16px */
  --space-3: 1.5rem;
  /* 24px */
  --space-4: 2rem;
  /* 32px */
  --space-5: 2.5rem;
  /* 40px */
  --space-6: 3rem;
  /* 48px */
  --space-8: 4rem;
  /* 64px */
  --space-10: 5rem;
  /* 80px */
  --space-12: 6rem;
  /* 96px */
  --space-16: 8rem;
  /* 128px */

  /* Border Radius */
  --radius-sm: 0.25rem;
  /* 4px */
  --radius-md: 0.5rem;
  /* 8px */
  --radius-lg: 0.75rem;
  /* 12px */
  --radius-xl: 1rem;
  /* 16px */
  --radius-2xl: 1.5rem;
  /* 24px */
  --radius-full: 9999px;

  /* Shadows */
  --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);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 300ms ease-in-out;
  --transition-slow: 500ms ease-in-out;

  /* Z-index Scale */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-normal);
  color: var(--color-gray-800);
  background-color: var(--color-white);
  overflow-x: hidden;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--color-primary);
  margin-bottom: var(--space-3);
}

h1 {
  font-size: var(--font-size-5xl);
  letter-spacing: -0.02em;
}

h2 {
  font-size: var(--font-size-4xl);
  letter-spacing: -0.01em;
}

h3 {
  font-size: var(--font-size-3xl);
}

h4 {
  font-size: var(--font-size-2xl);
}

h5 {
  font-size: var(--font-size-xl);
}

h6 {
  font-size: var(--font-size-lg);
}

p {
  margin-bottom: var(--space-3);
  color: var(--color-gray-700);
}

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

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

strong {
  font-weight: var(--font-weight-semibold);
}

/* ============================================
   LAYOUT UTILITIES
   ============================================ */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-4);
}

.container-narrow {
  max-width: 960px;
}

.container-wide {
  max-width: 1440px;
}

.section {
  padding: var(--space-12) 0;
}

.section-sm {
  padding: var(--space-8) 0;
}

.section-lg {
  padding: var(--space-16) 0;
}

/* ============================================
   GRID SYSTEM
   ============================================ */
.grid {
  display: grid;
  gap: var(--space-4);
}

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

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

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

/* Responsive Grid */
@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {

  .grid-3,
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  line-height: 1;
  text-align: center;
  text-decoration: none;
  border: 2px solid transparent;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-base);
  white-space: nowrap;
}

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

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

.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-primary:active:not(:disabled) {
  transform: translateY(0);
}

/* Secondary Button */
.btn-secondary {
  color: var(--color-primary);
  background-color: var(--color-white);
  border-color: var(--color-primary);
}

.btn-secondary:hover:not(:disabled) {
  color: var(--color-white);
  background-color: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* Accent Button */
.btn-accent {
  color: var(--color-white);
  background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-accent-dark) 100%);
  box-shadow: var(--shadow-md);
}

.btn-accent:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* Button Sizes */
.btn-sm {
  padding: var(--space-2) var(--space-3);
  font-size: var(--font-size-sm);
}

.btn-lg {
  padding: var(--space-4) var(--space-6);
  font-size: var(--font-size-lg);
}

.btn-block {
  width: 100%;
}

/* ============================================
   CARDS
   ============================================ */
.card {
  background-color: var(--color-white);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  transition: all var(--transition-base);
}

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

.card-header {
  padding: var(--space-4);
  border-bottom: 1px solid var(--color-gray-200);
}

.card-body {
  padding: var(--space-4);
}

.card-footer {
  padding: var(--space-4);
  border-top: 1px solid var(--color-gray-200);
  background-color: var(--color-gray-100);
}

/* Premium Card with Glassmorphism */
.card-premium {
  background: rgba(255, 255, 255, 0.9);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  box-shadow: var(--shadow-2xl);
}

/* ============================================
   FORMS
   ============================================ */
.form-group {
  margin-bottom: var(--space-4);
}

.form-label {
  display: block;
  margin-bottom: var(--space-2);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-gray-700);
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: var(--space-3);
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  color: var(--color-gray-800);
  background-color: var(--color-white);
  border: 2px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(26, 47, 90, 0.1);
}

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

.form-error {
  margin-top: var(--space-1);
  font-size: var(--font-size-sm);
  color: var(--color-error);
}

/* ============================================
   NAVIGATION
   ============================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-fixed);
  background-color: rgba(255, 255, 255, 0.95);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
}

.navbar-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
}

.navbar-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-heading);
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-primary);
  text-decoration: none;
}

.navbar-logo-img {
  height: 40px;
  width: auto;
  object-fit: contain;
}

.navbar-logo-text {
  color: var(--color-primary);
}

@media (max-width: 480px) {
  .navbar-logo-text {
    display: none;
  }

  .navbar-logo-img {
    height: 36px;
  }
}

.navbar-menu {
  display: flex;
  align-items: center;
  gap: var(--space-5);
  list-style: none;
}

.navbar-link {
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-medium);
  color: var(--color-gray-700);
  transition: color var(--transition-base);
}

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

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

/* Mobile Menu Toggle */
.navbar-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
}

.navbar-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-primary);
  transition: all var(--transition-base);
}

@media (max-width: 768px) {
  .navbar-toggle {
    display: flex;
  }

  .navbar-menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background-color: var(--color-white);
    box-shadow: var(--shadow-lg);
    padding: var(--space-4);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
  }

  .navbar-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .navbar-link {
    display: block;
    padding: var(--space-3) 0;
    border-bottom: 1px solid var(--color-gray-200);
  }
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
  background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary) 100%);
  color: var(--color-white);
  padding: var(--space-10) 0 var(--space-4);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-6);
  margin-bottom: var(--space-8);
}

.footer-section h4 {
  color: var(--color-white);
  margin-bottom: var(--space-3);
}

.footer-section p,
.footer-section a {
  color: var(--color-gray-300);
  font-size: var(--font-size-sm);
}

.footer-section a:hover {
  color: var(--color-accent-light);
}

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

.footer-links li {
  margin-bottom: var(--space-2);
}

.footer-bottom {
  padding-top: var(--space-4);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  font-size: var(--font-size-sm);
  color: var(--color-gray-400);
}

/* ============================================
   ANIMATIONS
   ============================================ */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }

  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }

  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes pulse {

  0%,
  100% {
    opacity: 1;
  }

  50% {
    opacity: 0.7;
  }
}

.fade-in {
  animation: fadeIn 0.6s ease-out;
}

.slide-in-left {
  animation: slideInLeft 0.6s ease-out;
}

.slide-in-right {
  animation: slideInRight 0.6s ease-out;
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.text-center {
  text-align: center;
}

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

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

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

.text-accent {
  color: var(--color-accent);
}

.text-gray {
  color: var(--color-gray-600);
}

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

.bg-accent {
  background-color: var(--color-accent);
}

.bg-gray-light {
  background-color: var(--color-gray-100);
}

.mt-1 {
  margin-top: var(--space-1);
}

.mt-2 {
  margin-top: var(--space-2);
}

.mt-3 {
  margin-top: var(--space-3);
}

.mt-4 {
  margin-top: var(--space-4);
}

.mt-6 {
  margin-top: var(--space-6);
}

.mt-8 {
  margin-top: var(--space-8);
}

.mb-1 {
  margin-bottom: var(--space-1);
}

.mb-2 {
  margin-bottom: var(--space-2);
}

.mb-3 {
  margin-bottom: var(--space-3);
}

.mb-4 {
  margin-bottom: var(--space-4);
}

.mb-6 {
  margin-bottom: var(--space-6);
}

.mb-8 {
  margin-bottom: var(--space-8);
}

.p-4 {
  padding: var(--space-4);
}

.p-6 {
  padding: var(--space-6);
}

.p-8 {
  padding: var(--space-8);
}

/* ============================================
   RESPONSIVE IMPROVEMENTS
   ============================================ */

/* Touch target sizes for mobile */
@media (max-width: 768px) {
  :root {
    --font-size-5xl: 2.5rem;
    --font-size-4xl: 2rem;
    --font-size-3xl: 1.5rem;
  }

  .container {
    padding: 0 var(--space-3);
  }

  /* Minimum touch target size */
  .btn,
  .navbar-link,
  .form-input,
  .form-select,
  .form-textarea {
    min-height: 44px;
  }

  .btn-sm {
    min-height: 40px;
    padding: var(--space-2) var(--space-3);
  }

  /* Better mobile navigation */
  .navbar-menu {
    max-height: calc(100vh - 70px);
    overflow-y: auto;
  }

  .navbar-menu li:last-child {
    padding-top: var(--space-3);
    border-bottom: none;
  }

  .navbar-menu .btn {
    width: 100%;
    justify-content: center;
  }

  /* Footer improvements */
  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--space-5);
    text-align: center;
  }

  .footer-section {
    padding-bottom: var(--space-4);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }

  .footer-section:last-child {
    border-bottom: none;
  }
}

@media (max-width: 600px) {
  :root {
    --font-size-5xl: 2.25rem;
    --font-size-4xl: 1.875rem;
    --font-size-3xl: 1.5rem;
    --font-size-2xl: 1.25rem;
  }

  .container {
    padding: 0 var(--space-2);
  }

  /* Improve button sizes on small screens */
  .btn-lg {
    padding: var(--space-3) var(--space-4);
    font-size: var(--font-size-base);
    width: 100%;
  }
}

@media (max-width: 480px) {
  :root {
    --font-size-5xl: 2rem;
    --font-size-4xl: 1.75rem;
    --font-size-3xl: 1.375rem;
    --font-size-2xl: 1.125rem;
  }

  .section {
    padding: var(--space-6) 0;
  }

  .section-lg {
    padding: var(--space-8) 0;
  }

  /* Card improvements */
  .card {
    border-radius: var(--radius-lg);
  }

  .card:hover {
    transform: none;
  }

  /* Form improvements */
  .form-input,
  .form-textarea,
  .form-select {
    font-size: 16px; /* Prevents iOS zoom on focus */
  }

  /* Footer compact on mobile */
  .footer {
    padding: var(--space-6) 0 var(--space-3);
  }

  .footer-content {
    margin-bottom: var(--space-4);
  }
}

/* ============================================
   ACCESSIBILITY IMPROVEMENTS
   ============================================ */

/* Focus styles */
.btn:focus-visible,
.form-input:focus-visible,
.form-textarea:focus-visible,
.form-select:focus-visible,
.navbar-link:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

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

  html {
    scroll-behavior: auto;
  }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  .btn-primary {
    border: 2px solid var(--color-white);
  }

  .card {
    border: 2px solid var(--color-gray-800);
  }
}

/* Print styles */
@media print {
  .navbar,
  .footer,
  .btn {
    display: none;
  }

  body {
    font-size: 12pt;
    color: black;
    background: white;
  }

  .section {
    padding: 1rem 0;
  }
}