/* ============================================================================
   FREEPDFCONVERT - PRODUCTION-GRADE CSS SYSTEM
   Psychology-Driven Design with Accessibility
   ============================================================================ */

:root {
  /* Color Palette - Stability & Action */
  --color-primary: #1E40AF;
  --color-primary-light: #3B82F6;
  --color-primary-dark: #1E3A8A;
  --color-action: #F97316;
  --color-action-light: #FB923C;
  --color-action-dark: #EA580C;
  
  /* Neutral Palette */
  --color-bg-primary: #0F172A;
  --color-bg-secondary: #1E293B;
  --color-text-primary: #FFFFFF;
  --color-text-secondary: #CBD5E1;
  --color-border: #334155;
  
  /* Status Colors */
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-error: #EF4444;
  --color-info: #0EA5E9;
  
  /* Spacing Scale */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  
  /* Typography */
  --font-family: 'Inter', 'Verdana', sans-serif;
  --font-size-xs: 12px;
  --font-size-sm: 14px;
  --font-size-md: 16px;
  --font-size-lg: 18px;
  --font-size-xl: 20px;
  --font-size-2xl: 24px;
  --font-size-3xl: 32px;
  --font-size-4xl: 40px;
  
  /* Line Heights */
  --line-height-tight: 1.3;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
  
  /* Border Radius */
  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 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 cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============================================================================
   RESET & BASE STYLES
   ============================================================================ */

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

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

body {
  font-family: var(--font-family);
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
  line-height: var(--line-height-normal);
  font-size: var(--font-size-md);
  overflow-x: hidden;
}

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

button {
  cursor: pointer;
  border: none;
  background: none;
}

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

a:hover {
  color: var(--color-primary);
  text-decoration: underline;
}

/* Focus Visible for Accessibility */
:focus-visible {
  outline: 2px solid var(--color-primary-light);
  outline-offset: 2px;
}

button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  outline: 2px solid var(--color-action);
  outline-offset: 2px;
}

/* ============================================================================
   SECURITY BANNER - Trust Signal
   ============================================================================ */

.security-banner {
  background: linear-gradient(135deg, rgba(30, 64, 175, 0.1) 0%, rgba(8, 145, 178, 0.1) 100%);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-md) var(--space-lg);
  backdrop-filter: blur(10px);
  position: sticky;
  top: 0;
  z-index: 100;
  animation: slideDown 0.3s ease-out;
}

.security-banner-content {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: var(--space-md);
  justify-content: space-between;
}

.security-icon {
  color: var(--color-success);
  flex-shrink: 0;
  filter: drop-shadow(0 0 8px rgba(16, 185, 129, 0.3));
}

.security-text {
  flex: 1;
  font-size: var(--font-size-sm);
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.security-text strong {
  font-weight: 600;
}

.security-close {
  flex-shrink: 0;
  font-size: var(--font-size-lg);
  opacity: 0.7;
  transition: opacity var(--transition-fast);
  padding: var(--space-xs) var(--space-sm);
}

.security-close:hover {
  opacity: 1;
}

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

.header {
  background-color: var(--color-bg-secondary);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-lg) 0;
  position: sticky;
  top: 48px;
  z-index: 50;
  animation: slideDown 0.4s ease-out;
}

.header-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-2xl);
}

.logo-section {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  flex-shrink: 0;
}

.logo-icon {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-action) 100%);
  padding: var(--space-xs);
  border-radius: var(--radius-md);
  filter: drop-shadow(0 4px 12px rgba(30, 64, 175, 0.3));
}

.logo-text {
  font-size: var(--font-size-xl);
  font-weight: 700;
  letter-spacing: -0.5px;
}

.nav-menu {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.nav-item {
  padding: var(--space-sm) var(--space-lg);
  border-radius: var(--radius-md);
  font-weight: 500;
  font-size: var(--font-size-sm);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.nav-item::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--color-primary-light);
  opacity: 0;
  transition: opacity var(--transition-base);
  z-index: -1;
}

.nav-item:hover::before {
  opacity: 0.1;
}

.nav-item.active {
  background: var(--color-primary);
  box-shadow: 0 0 20px rgba(30, 64, 175, 0.4);
}

/* ============================================================================
   HERO SECTION - Above the Fold Design
   ============================================================================ */

.hero {
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--space-3xl) var(--space-lg);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
  animation: fadeInUp 0.6s ease-out;
}

.hero-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.hero-title {
  font-size: var(--font-size-4xl);
  font-weight: 800;
  line-height: var(--line-height-tight);
  background: linear-gradient(135deg, var(--color-text-primary) 0%, var(--color-text-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -1px;
}

.hero-subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
  max-width: 600px;
}

.hero-cta {
  display: flex;
  gap: var(--space-md);
  margin-top: var(--space-md);
}

.hero-visual {
  position: relative;
  height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.floating-card {
  position: absolute;
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border);
  background: linear-gradient(135deg, rgba(30, 64, 175, 0.1) 0%, rgba(8, 145, 178, 0.05) 100%);
  backdrop-filter: blur(10px);
  animation: float 6s ease-in-out infinite;
}

.card-1 {
  width: 200px;
  height: 140px;
  top: 20px;
  left: 20px;
  animation-delay: 0s;
  box-shadow: 0 8px 32px rgba(30, 64, 175, 0.2);
}

.card-2 {
  width: 180px;
  height: 120px;
  top: 140px;
  right: 40px;
  animation-delay: 1s;
  box-shadow: 0 8px 32px rgba(249, 115, 22, 0.2);
}

.card-3 {
  width: 160px;
  height: 100px;
  bottom: 30px;
  left: 80px;
  animation-delay: 2s;
  box-shadow: 0 8px 32px rgba(16, 185, 129, 0.2);
}

/* ============================================================================
   DROPZONE - Universal File Upload
   ============================================================================ */

.dropzone-section {
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-lg);
  animation: fadeInUp 0.8s ease-out;
}

.dropzone-container {
  position: relative;
}

.dropzone {
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-3xl);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-base);
  background: linear-gradient(135deg, rgba(30, 64, 175, 0.03) 0%, rgba(8, 145, 178, 0.03) 100%);
  position: relative;
  overflow: hidden;
}

.dropzone::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at center, rgba(30, 64, 175, 0.05) 0%, transparent 70%);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.dropzone:hover,
.dropzone.dragover {
  border-color: var(--color-primary-light);
  background: linear-gradient(135deg, rgba(30, 64, 175, 0.08) 0%, rgba(8, 145, 178, 0.08) 100%);
}

.dropzone:hover::before,
.dropzone.dragover::before {
  opacity: 1;
}

.dropzone-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
}

.dropzone-icon {
  color: var(--color-primary-light);
  filter: drop-shadow(0 0 8px rgba(30, 64, 175, 0.3));
  animation: bounce 2s ease-in-out infinite;
}

.dropzone-title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
}

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

#file-input {
  display: none;
}

.dropzone-loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-lg);
  padding: var(--space-2xl) 0;
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid rgba(255, 255, 255, 0.1);
  border-top-color: var(--color-primary-light);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

.loading-text {
  color: var(--color-text-secondary);
}

.progress-bar {
  width: 100%;
  max-width: 300px;
  height: 4px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-full);
  overflow: hidden;
  position: relative;
}

.progress-bar::after {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-action));
  animation: progress 3s ease-in-out forwards;
}

/* ============================================================================
   BUTTONS - Call to Action
   ============================================================================ */

.btn {
  padding: var(--space-sm) var(--space-lg);
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: var(--font-size-md);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  white-space: nowrap;
  min-height: 44px;
}

.btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(45deg, transparent 30%, rgba(255, 255, 255, 0.1) 50%, transparent 70%);
  transform: translateX(-100%);
  transition: transform var(--transition-base);
}

.btn:hover::before {
  transform: translateX(100%);
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: white;
  box-shadow: 0 4px 15px rgba(30, 64, 175, 0.4);
}

.btn-primary:hover {
  box-shadow: 0 8px 25px rgba(30, 64, 175, 0.6);
  transform: translateY(-2px);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid var(--color-border);
  color: var(--color-text-primary);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: var(--color-primary-light);
}

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

/* ============================================================================
   TOOLS SECTION - 3 Column Grid Layout
   ============================================================================ */

.tools-section {
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--space-3xl) var(--space-lg);
  animation: fadeInUp 1s ease-out;
}

.tools-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
  gap: var(--space-2xl);
}

.tools-column {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.column-title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  padding-bottom: var(--space-md);
  border-bottom: 1px solid var(--color-border);
}

/* ============================================================================
   TOOL CARDS - Interactive Containers
   ============================================================================ */

.tool-card {
  background: linear-gradient(135deg, rgba(30, 64, 175, 0.05) 0%, rgba(8, 145, 178, 0.03) 100%);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-lg);
  transition: all var(--transition-base);
  backdrop-filter: blur(10px);
}

.tool-card:hover {
  border-color: var(--color-primary-light);
  box-shadow: 0 8px 24px rgba(30, 64, 175, 0.15);
  transform: translateY(-4px);
}

.tool-header {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-md);
}

.tool-icon {
  flex-shrink: 0;
  background: rgba(30, 64, 175, 0.1);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  filter: drop-shadow(0 2px 8px rgba(30, 64, 175, 0.2));
}

.tool-title {
  font-size: var(--font-size-lg);
  font-weight: 700;
  margin: 0;
}

.tool-description {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
}

.tool-controls {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

/* ============================================================================
   FORM ELEMENTS & CONTROLS
   ============================================================================ */

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.form-label {
  font-weight: 600;
  font-size: var(--font-size-sm);
}

.form-input,
.form-range {
  padding: var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.05);
  color: var(--color-text-primary);
  transition: all var(--transition-base);
}

.form-input:focus,
.form-range:focus {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--color-primary-light);
}

.form-hint {
  font-size: var(--font-size-xs);
  color: var(--color-text-secondary);
  margin-top: var(--space-xs);
}

.form-range {
  height: 6px;
  padding: 0;
  cursor: pointer;
}

.form-range::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-primary-light);
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(30, 64, 175, 0.4);
}

.form-range::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-primary-light);
  cursor: pointer;
  border: none;
  box-shadow: 0 2px 8px rgba(30, 64, 175, 0.4);
}

/* Radio & Checkbox Options */

.radio-option {
  display: flex;
  align-items: center;
  padding: var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  gap: var(--space-md);
}

.radio-option input[type="radio"] {
  width: 18px;
  height: 18px;
  cursor: pointer;
  accent-color: var(--color-primary-light);
}

.radio-option:hover {
  border-color: var(--color-primary-light);
  background: rgba(30, 64, 175, 0.05);
}

.radio-option input[type="radio"]:checked + .radio-label {
  color: var(--color-primary-light);
  font-weight: 600;
}

.radio-label {
  flex: 1;
  font-weight: 500;
}

.radio-sublabel {
  font-size: var(--font-size-xs);
  color: var(--color-text-secondary);
  display: block;
}

.compression-options {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.layout-toggle,
.format-toggle {
  display: flex;
  gap: var(--space-sm);
}

.layout-toggle label,
.format-toggle label {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
}

.layout-toggle input,
.format-toggle input {
  width: 16px;
  height: 16px;
  cursor: pointer;
  accent-color: var(--color-primary-light);
}

.layout-toggle label:hover,
.format-toggle label:hover {
  border-color: var(--color-primary-light);
  background: rgba(30, 64, 175, 0.05);
}

.layout-toggle input:checked + span,
.format-toggle input:checked + span {
  color: var(--color-primary-light);
  font-weight: 600;
}

/* Value Display */

.quality-value,
.opacity-value {
  font-weight: 600;
  color: var(--color-primary-light);
}

/* ============================================================================
   IMAGE PREVIEW GRID
   ============================================================================ */

.image-preview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
  gap: var(--space-md);
  padding: var(--space-md);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-md);
  min-height: 120px;
}

.preview-item {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.05);
  aspect-ratio: 1 / 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.preview-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.preview-remove {
  position: absolute;
  top: 4px;
  right: 4px;
  background: rgba(0, 0, 0, 0.6);
  border: none;
  border-radius: 50%;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  transition: opacity var(--transition-base);
}

.preview-item:hover .preview-remove {
  opacity: 1;
}

/* ============================================================================
   MERGE & SPLIT LISTS
   ============================================================================ */

.merge-list,
.split-options {
  max-height: 300px;
  overflow-y: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
}

.merge-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-sm);
  cursor: grab;
  transition: all var(--transition-base);
}

.merge-item:hover {
  border-color: var(--color-primary-light);
  background: rgba(30, 64, 175, 0.05);
}

.merge-item-name {
  flex: 1;
  font-weight: 500;
}

.merge-item-size {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  margin-right: var(--space-md);
}

.merge-remove {
  background: var(--color-error);
  color: white;
  border: none;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: var(--font-size-xs);
}

.merge-actions {
  display: flex;
  gap: var(--space-md);
  margin-top: var(--space-md);
}

/* ============================================================================
   RESULTS SECTION - Success State
   ============================================================================ */

.results-section {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  animation: fadeIn 0.3s ease-out;
}

.results-container {
  padding: var(--space-lg);
}

.results-card {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  max-width: 500px;
  width: 100%;
  box-shadow: var(--shadow-2xl);
  animation: slideUp 0.4s ease-out;
}

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

.results-title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
}

.results-close {
  font-size: var(--font-size-2xl);
  cursor: pointer;
  opacity: 0.7;
  transition: opacity var(--transition-base);
}

.results-close:hover {
  opacity: 1;
}

.results-content {
  padding: var(--space-lg);
}

.file-stats {
  background: rgba(30, 64, 175, 0.05);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.stat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.stat-label {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.stat-value {
  font-weight: 700;
  font-size: var(--font-size-md);
  color: var(--color-primary-light);
}

.download-area {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

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

.footer {
  background: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border);
  padding: var(--space-2xl) var(--space-lg);
  margin-top: var(--space-3xl);
}

.footer-content {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-lg);
}

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

.footer-links {
  display: flex;
  gap: var(--space-lg);
}

.footer-links a {
  font-size: var(--font-size-sm);
  transition: color var(--transition-base);
}

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

/* ============================================================================
   ANIMATIONS - Keyframe Effects
   ============================================================================ */

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

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

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

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

@keyframes float {
  0%, 100% {
    transform: translateY(0px) rotate(0deg);
  }
  50% {
    transform: translateY(-20px) rotate(2deg);
  }
}

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

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

@keyframes progress {
  to {
    width: 100%;
  }
}

/* ============================================================================
   RESPONSIVE DESIGN - Mobile Optimization
   ============================================================================ */

@media (max-width: 768px) {
  :root {
    --font-size-4xl: 32px;
    --font-size-3xl: 24px;
    --space-3xl: 32px;
  }

  .header-container {
    flex-direction: column;
    gap: var(--space-md);
  }

  .hero {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
    padding: var(--space-2xl) var(--space-lg);
  }

  .hero-visual {
    min-height: 300px;
  }

  .tools-container {
    grid-template-columns: 1fr;
  }

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

  .footer-content {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 480px) {
  :root {
    --font-size-4xl: 24px;
    --font-size-2xl: 20px;
    --space-2xl: 32px;
    --space-lg: 16px;
  }

  .dropzone {
    padding: var(--space-lg);
  }

  .security-banner-content {
    flex-direction: column;
    align-items: flex-start;
  }

  .layout-toggle,
  .format-toggle {
    flex-direction: column;
  }
}

/* ============================================================================
   ACCESSIBILITY - High Contrast Mode
   ============================================================================ */

@media (prefers-contrast: more) {
  .tool-card,
  .radio-option {
    border-width: 2px;
  }

  .btn {
    min-height: 48px;
  }
}

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

/* ============================================================================
   SCROLLBAR STYLING
   ============================================================================ */

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.05);
}

::-webkit-scrollbar-thumb {
  background: rgba(30, 64, 175, 0.4);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(30, 64, 175, 0.6);
}