/* ============================================
   PDF Tools - Main Design System
   Modern, Premium, Responsive
   ============================================ */

/* ============================================
   CSS VARIABLES & DESIGN TOKENS
   ============================================ */
:root {
  /* Primary Colors */
  --primary: hsl(220, 90%, 56%);
  --primary-light: hsl(220, 90%, 65%);
  --primary-dark: hsl(220, 90%, 45%);
  --primary-glow: hsla(220, 90%, 56%, 0.4);
  
  /* Secondary Colors */
  --secondary: hsl(280, 80%, 60%);
  --secondary-light: hsl(280, 80%, 70%);
  --secondary-dark: hsl(280, 80%, 50%);
  
  /* Accent Colors */
  --accent-cyan: hsl(185, 80%, 50%);
  --accent-orange: hsl(25, 95%, 55%);
  --accent-pink: hsl(330, 85%, 60%);
  --accent-green: hsl(145, 70%, 45%);
  
  /* Status Colors */
  --success: hsl(145, 70%, 45%);
  --warning: hsl(35, 90%, 55%);
  --danger: hsl(0, 75%, 55%);
  --info: hsl(200, 85%, 55%);
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  --gradient-hero: linear-gradient(135deg, hsl(220, 90%, 56%) 0%, hsl(280, 80%, 60%) 50%, hsl(330, 85%, 60%) 100%);
  --gradient-card: linear-gradient(145deg, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0.05) 100%);
  --gradient-glow: radial-gradient(circle at 50% 50%, var(--primary-glow) 0%, transparent 70%);
  
  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-display: 'Outfit', var(--font-primary);
  
  /* Font Sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  --text-6xl: 3.75rem;
  
  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;
  
  /* Shadows - Light Mode */
  --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 -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --shadow-glow: 0 0 40px var(--primary-glow);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 300ms ease;
  --transition-slow: 500ms ease;
  --transition-bounce: 500ms cubic-bezier(0.68, -0.55, 0.265, 1.55);
  
  /* Z-Index */
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal-backdrop: 400;
  --z-modal: 500;
  --z-tooltip: 600;
  --z-toast: 700;
  
  /* Light Mode (Default) */
  --bg-primary: hsl(220, 30%, 97%);
  --bg-secondary: hsl(220, 25%, 93%);
  --bg-tertiary: hsl(0, 0%, 100%);
  --surface: hsl(0, 0%, 100%);
  --surface-elevated: hsl(0, 0%, 100%);
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.3);
  --text-primary: hsl(220, 25%, 10%);
  --text-secondary: hsl(220, 15%, 40%);
  --text-muted: hsl(220, 10%, 55%);
  --border-color: hsl(220, 20%, 88%);
  --border-subtle: hsl(220, 20%, 92%);
}

/* Dark Mode */
[data-theme="dark"] {
  --bg-primary: hsl(220, 25%, 8%);
  --bg-secondary: hsl(220, 20%, 12%);
  --bg-tertiary: hsl(220, 22%, 15%);
  --surface: hsl(220, 22%, 13%);
  --surface-elevated: hsl(220, 20%, 16%);
  --glass-bg: rgba(30, 35, 50, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
  --text-primary: hsl(220, 20%, 95%);
  --text-secondary: hsl(220, 15%, 70%);
  --text-muted: hsl(220, 10%, 50%);
  --border-color: hsl(220, 20%, 22%);
  --border-subtle: hsl(220, 20%, 18%);
  
  /* Dark Mode Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -4px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.4);
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-primary);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-primary);
  min-height: 100vh;
  overflow-x: hidden;
  transition: background-color var(--transition-base), color var(--transition-base);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-primary);
}

h1 { font-size: var(--text-5xl); }
h2 { font-size: var(--text-4xl); }
h3 { font-size: var(--text-3xl); }
h4 { font-size: var(--text-2xl); }
h5 { font-size: var(--text-xl); }
h6 { font-size: var(--text-lg); }

p {
  color: var(--text-secondary);
  margin-bottom: var(--space-4);
}

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

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

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

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

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

ul, ol {
  list-style: none;
}

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

/* Flex */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

/* Grid */
.grid { display: grid; }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

/* Text */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.text-gradient {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.text-sm { font-size: var(--text-sm); }
.text-lg { font-size: var(--text-lg); }
.text-xl { font-size: var(--text-xl); }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

/* Spacing */
.mt-2 { margin-top: var(--space-2); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }
.p-2 { padding: var(--space-2); }
.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }
.px-4 { padding-left: var(--space-4); padding-right: var(--space-4); }
.py-2 { padding-top: var(--space-2); padding-bottom: var(--space-2); }
.py-4 { padding-top: var(--space-4); padding-bottom: var(--space-4); }

/* Visibility */
.hidden { display: none !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: 0;
}

/* ============================================
   ANIMATION KEYFRAMES
   ============================================ */
@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(-30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-10px); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

@keyframes rotate {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

/* Animation Classes */
.animate-fadeIn { animation: fadeIn 0.5s ease forwards; }
.animate-fadeInUp { animation: fadeInUp 0.6s ease forwards; }
.animate-fadeInDown { animation: fadeInDown 0.6s ease forwards; }
.animate-slideInLeft { animation: slideInLeft 0.6s ease forwards; }
.animate-slideInRight { animation: slideInRight 0.6s ease forwards; }
.animate-scaleIn { animation: scaleIn 0.4s ease forwards; }
.animate-float { animation: float 3s ease-in-out infinite; }
.animate-pulse { animation: pulse 2s ease-in-out infinite; }

/* Stagger Delays */
.delay-100 { animation-delay: 100ms; }
.delay-200 { animation-delay: 200ms; }
.delay-300 { animation-delay: 300ms; }
.delay-400 { animation-delay: 400ms; }
.delay-500 { animation-delay: 500ms; }

/* ============================================
   CONTAINER & LAYOUT
   ============================================ */
.container {
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.container-sm {
  max-width: 800px;
}

.container-lg {
  max-width: 1600px;
}

.section {
  padding: var(--space-20) 0;
}

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

/* ============================================
   GLASSMORPHISM COMPONENTS
   ============================================ */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
}

.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  box-shadow: var(--shadow-lg);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

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

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-base);
  font-weight: 600;
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.2) 0%, transparent 50%);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.btn:hover::before {
  opacity: 1;
}

.btn-primary {
  background: var(--gradient-primary);
  color: white;
  box-shadow: 0 4px 15px var(--primary-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 25px var(--primary-glow);
}

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

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

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

.btn-ghost:hover {
  background: var(--bg-secondary);
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-lg);
  border-radius: var(--radius-xl);
}

.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
}

.btn-icon {
  width: 44px;
  height: 44px;
  padding: 0;
  border-radius: var(--radius-lg);
}

.btn-icon svg {
  width: 20px;
  height: 20px;
}

/* ============================================
   CARDS
   ============================================ */
.card {
  background: var(--surface);
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-subtle);
  padding: var(--space-6);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
}

.card:hover {
  border-color: var(--border-color);
  box-shadow: var(--shadow-lg);
}

.card-interactive:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  box-shadow: var(--shadow-xl), 0 0 30px var(--primary-glow);
}

/* ============================================
   INPUTS & FORMS
   ============================================ */
.input {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-base);
  color: var(--text-primary);
  background: var(--surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  transition: all var(--transition-fast);
}

.input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

.input::placeholder {
  color: var(--text-muted);
}

.input-group {
  position: relative;
}

.input-group .input {
  padding-left: 44px;
}

.input-group .input-icon {
  position: absolute;
  left: var(--space-4);
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

/* ============================================
   BADGES & TAGS
   ============================================ */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

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

.badge-success {
  background: hsla(145, 70%, 45%, 0.2);
  color: var(--success);
}

.badge-warning {
  background: hsla(35, 90%, 55%, 0.2);
  color: var(--warning);
}

.badge-danger {
  background: hsla(0, 75%, 55%, 0.2);
  color: var(--danger);
}

/* ============================================
   TOOLTIPS
   ============================================ */
.tooltip {
  position: relative;
}

.tooltip::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(-8px);
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  font-weight: 500;
  color: white;
  background: var(--text-primary);
  border-radius: var(--radius-md);
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-fast);
  z-index: var(--z-tooltip);
}

.tooltip:hover::after {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(-4px);
}

/* ============================================
   TOAST NOTIFICATIONS
   ============================================ */
.toast-container {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.toast {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  background: var(--surface-elevated);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  animation: slideInRight 0.3s ease;
  max-width: 400px;
}

.toast-icon {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

.toast-success .toast-icon { color: var(--success); }
.toast-error .toast-icon { color: var(--danger); }
.toast-warning .toast-icon { color: var(--warning); }
.toast-info .toast-icon { color: var(--info); }

.toast-content {
  flex: 1;
}

.toast-title {
  font-weight: 600;
  color: var(--text-primary);
}

.toast-message {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin-top: var(--space-1);
}

.toast-close {
  background: none;
  color: var(--text-muted);
  padding: var(--space-1);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.toast-close:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

/* ============================================
   MODAL
   ============================================ */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  z-index: var(--z-modal-backdrop);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.modal-backdrop.active {
  opacity: 1;
  visibility: visible;
}

.modal {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0.95);
  background: var(--surface);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-xl);
  z-index: var(--z-modal);
  max-width: 90vw;
  max-height: 90vh;
  overflow: hidden;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.modal.active {
  opacity: 1;
  visibility: visible;
  transform: translate(-50%, -50%) scale(1);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-6);
  border-bottom: 1px solid var(--border-subtle);
}

.modal-title {
  font-size: var(--text-xl);
  font-weight: 700;
}

.modal-body {
  padding: var(--space-6);
  overflow-y: auto;
}

.modal-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-6);
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-secondary);
}

/* ============================================
   PROGRESS BAR
   ============================================ */
.progress {
  width: 100%;
  height: 8px;
  background: var(--bg-secondary);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  transition: width var(--transition-base);
  position: relative;
}

.progress-bar::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    transparent 0%,
    rgba(255, 255, 255, 0.3) 50%,
    transparent 100%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}

/* ============================================
   LOADER / SPINNER
   ============================================ */
.loader {
  width: 40px;
  height: 40px;
  border: 3px solid var(--border-color);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: rotate 0.8s linear infinite;
}

.loader-sm {
  width: 24px;
  height: 24px;
  border-width: 2px;
}

.loader-lg {
  width: 56px;
  height: 56px;
  border-width: 4px;
}

/* ============================================
   DROPZONE / FILE UPLOAD
   ============================================ */
.dropzone {
  border: 2px dashed var(--border-color);
  border-radius: var(--radius-2xl);
  padding: var(--space-12);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-base);
  background: var(--surface);
}

.dropzone:hover,
.dropzone.dragover {
  border-color: var(--primary);
  background: var(--primary-glow);
}

.dropzone-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--space-4);
  color: var(--primary);
}

.dropzone-title {
  font-size: var(--text-xl);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}

.dropzone-subtitle {
  color: var(--text-secondary);
  font-size: var(--text-sm);
}

.dropzone-hint {
  margin-top: var(--space-4);
  font-size: var(--text-xs);
  color: var(--text-muted);
}

/* ============================================
   SCROLLBAR
   ============================================ */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: var(--radius-full);
  border: 2px solid var(--bg-secondary);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* Firefox */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--border-color) var(--bg-secondary);
}

/* ============================================
   SELECTION
   ============================================ */
::selection {
  background: var(--primary);
  color: white;
}

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