/* ============================================
   Navigation Bar
   ============================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  transition: all var(--transition-base);
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  box-shadow: 0 1px 20px rgba(0, 0, 0, 0.06);
}

.navbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.nav-logo-icon {
  width: 36px;
  height: 36px;
  background: var(--gradient-primary);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 18px;
}

.nav-logo-text span:first-child {
  color: var(--gray-900);
}

.nav-logo-text span:last-child {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  padding: 8px 18px;
  font-size: 15px;
  font-weight: 500;
  color: var(--gray-600);
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
  position: relative;
}

.nav-link:hover {
  color: var(--primary-600);
  background: var(--primary-50);
}

.nav-link.active {
  color: var(--primary-600);
  background: var(--primary-50);
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 22px;
  background: var(--gradient-primary);
  color: white;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
  box-shadow: 0 2px 12px rgba(99, 102, 241, 0.3);
}

.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(99, 102, 241, 0.4);
}

/* Mobile Menu Toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 28px;
  padding: 4px 0;
  cursor: pointer;
}

.nav-toggle span {
  height: 2.5px;
  background: var(--gray-700);
  border-radius: 2px;
  transition: all var(--transition-base);
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile Menu Panel */
.mobile-menu {
  display: none;
  position: fixed;
  top: var(--nav-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(20px);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.mobile-menu.open {
  opacity: 1;
  visibility: visible;
}

.mobile-menu-inner {
  display: flex;
  flex-direction: column;
  padding: 24px;
  gap: 8px;
}

.mobile-menu .nav-link {
  font-size: 18px;
  padding: 14px 20px;
  border-radius: var(--radius-md);
}

.mobile-menu .nav-link:hover {
  background: var(--primary-50);
}

/* ============================================
   Hero Section
   ============================================ */
.hero-section {
  position: relative;
  padding-top: calc(var(--nav-height) + 60px);
  padding-bottom: 40px;
  background: var(--gradient-hero-bg);
  overflow: hidden;
}

/* Decorative background elements */
.hero-bg-decor {
  position: absolute;
  pointer-events: none;
}

.hero-bg-decor.blob-1 {
  top: -100px;
  right: -150px;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.08) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-bg-decor.blob-2 {
  bottom: -80px;
  left: -100px;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(139, 92, 246, 0.06) 0%, transparent 70%);
  border-radius: 50%;
}

/* Wave separator */
.wave-separator {
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 100%;
  overflow: hidden;
  line-height: 0;
}

.wave-separator svg {
  display: block;
  width: 100%;
  height: 60px;
}

.hero-content {
  text-align: center;
  max-width: 720px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: var(--primary-50);
  border: 1px solid var(--primary-200);
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 600;
  color: var(--primary-600);
  margin-bottom: 28px;
}

.hero-badge-dot {
  width: 7px;
  height: 7px;
  background: var(--success);
  border-radius: 50%;
  animation: pulse-ring 2s ease-out infinite;
}

.hero-title {
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -1.5px;
  color: var(--gray-900);
  margin-bottom: 20px;
}

.hero-title .highlight {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 18px;
  line-height: 1.6;
  color: var(--gray-500);
  margin-bottom: 16px;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 32px;
  margin-top: 32px;
  padding: 20px 0;
}

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

.hero-stat-value {
  font-size: 28px;
  font-weight: 700;
  color: var(--gray-900);
}

.hero-stat-label {
  font-size: 13px;
  color: var(--gray-400);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* ============================================
   Upload Zone (Core Feature)
   ============================================ */
.upload-section {
  position: relative;
  padding: 60px 0 80px;
  background: var(--white);
}

.upload-container {
  max-width: 680px;
  margin: 0 auto;
}

.upload-zone {
  position: relative;
  border: 2px dashed var(--gray-300);
  border-radius: var(--radius-xl);
  background: var(--white);
  transition: all var(--transition-base);
  overflow: hidden;
}

.upload-zone:hover,
.upload-zone.dragover {
  border-color: var(--primary-400);
  background: var(--primary-50);
  transform: scale(1.01);
  box-shadow: var(--shadow-glow);
}

.upload-zone.dragover {
  transform: scale(1.02);
  border-style: solid;
  border-color: var(--primary-500);
}

.upload-zone-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 60px 40px;
  text-align: center;
  min-height: 360px;
}

.upload-icon-wrapper {
  position: relative;
  width: 88px;
  height: 88px;
  margin-bottom: 24px;
}

.upload-icon-circle {
  position: absolute;
  inset: 0;
  background: var(--gradient-primary);
  opacity: 0.1;
  border-radius: 50%;
  animation: pulse-ring 3s ease-out infinite;
}

.upload-icon {
  position: relative;
  width: 88px;
  height: 88px;
  background: linear-gradient(135deg, var(--primary-50), var(--secondary-50));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary-500);
  transition: all var(--transition-base);
}

.upload-zone:hover .upload-icon,
.upload-zone.dragover .upload-icon {
  transform: translateY(-4px);
  background: var(--gradient-primary);
  color: white;
  box-shadow: 0 8px 30px rgba(99, 102, 241, 0.25);
}

.upload-title {
  font-size: 20px;
  font-weight: 600;
  color: var(--gray-800);
  margin-bottom: 8px;
}

.upload-subtitle {
  font-size: 15px;
  color: var(--gray-400);
  margin-bottom: 24px;
}

.upload-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 30px;
  background: var(--gradient-primary);
  color: white;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
  box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.upload-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(99, 102, 241, 0.4);
}

.upload-formats {
  margin-top: 20px;
  font-size: 13px;
  color: var(--gray-400);
  display: flex;
  align-items: center;
  gap: 8px;
}

.format-tag {
  padding: 3px 10px;
  background: var(--gray-100);
  border-radius: var(--radius-sm);
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 11px;
  font-weight: 600;
  color: var(--gray-500);
  text-transform: uppercase;
}

#file-input {
  display: none;
}

/* ============================================
   Processing State
   ============================================ */
.processing-state {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 70px 40px;
  text-align: center;
  min-height: 380px;
}

.processing-state.active {
  display: flex;
  animation: fadeInUp 0.4s ease-out;
}

.spinner-wrapper {
  position: relative;
  width: 72px;
  height: 72px;
  margin-bottom: 28px;
}

.spinner-ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  animation: pulse-ring 2s cubic-bezier(0.215, 0.61, 0.355, 1) infinite;
}

.spinner-ring:nth-child(1) {
  background: rgba(99, 102, 241, 0.15);
  animation-delay: 0s;
}

.spinner-ring:nth-child(2) {
  background: rgba(139, 92, 246, 0.1);
  animation-delay: 0.5s;
}

.spinner {
  position: absolute;
  inset: 12px;
  border: 3px solid var(--gray-100);
  border-top-color: var(--primary-500);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

.processing-text {
  font-size: 18px;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 8px;
}

.processing-hint {
  font-size: 14px;
  color: var(--gray-400);
}

.preview-thumb {
  width: 120px;
  height: 120px;
  object-fit: cover;
  border-radius: var(--radius-md);
  margin-bottom: 20px;
  box-shadow: var(--shadow-md);
}

.progress-bar {
  width: 200px;
  height: 4px;
  background: var(--gray-200);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-top: 24px;
}

.progress-bar-fill {
  height: 100%;
  width: 45%;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  animation: shimmer 1.5s ease-in-out infinite;
  background-size: 200% 100%;
}

/* ============================================
   Result Display (Before/After Comparison)
   ============================================ */
.result-state {
  display: none;
  flex-direction: column;
  animation: bounce-in 0.5s ease-out;
}

.result-state.active {
  display: flex;
}

.result-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
  flex-wrap: wrap;
  gap: 12px;
}

.quota-info {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--gray-500);
  padding: 6px 14px;
  background: var(--gray-50);
  border-radius: var(--radius-full);
}

.quota-info strong {
  color: var(--primary-600);
}

.comparison-container {
  position: relative;
  width: 100%;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-xl);
  aspect-ratio: 16/10;
  user-select: none;
  touch-action: pan-y;
}

.comparison-images {
  position: relative;
  width: 100%;
  height: 100%;
}

.comparison-original,
.comparison-result {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.comparison-original {
  /* Original image on the left */
}

.comparison-result {
  clip-path: inset(0 50% 0 0);
}

/* Checkered pattern for transparency preview */
.checkered-bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(45deg, #e0e0e0 25%, transparent 25%),
    linear-gradient(-45deg, #e0e0e0 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #e0e0e0 75%),
    linear-gradient(-45deg, transparent 75%, #e0e0e0 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
  background-color: #fff;
  z-index: 0;
}

.comparison-result-img {
  position: relative;
  z-index: 1;
}

.comparison-slider {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 3px;
  background: white;
  cursor: ew-resize;
  z-index: 10;
  transform: translateX(-50%);
  box-shadow: 0 0 12px rgba(0, 0, 0, 0.2);
}

.comparison-slider::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 44px;
  height: 44px;
  background: white;
  border-radius: 50%;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.15);
}

.comparison-slider::after {
  content: '⟨ ⟩';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scaleX(0.85);
  font-size: 14px;
  font-weight: 300;
  color: var(--gray-400);
  letter-spacing: 4px;
  white-space: nowrap;
  line-height: 1;
}

/* Labels overlay */
.comparison-labels {
  position: absolute;
  top: 16px;
  left: 0;
  right: 0;
  display: flex;
  justify-content: space-between;
  padding: 0 20px;
  z-index: 5;
  pointer-events: none;
}

.label-badge {
  padding: 6px 14px;
  background: rgba(17, 24, 39, 0.65);
  backdrop-filter: blur(8px);
  color: white;
  font-size: 12px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.result-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-top: 28px;
  flex-wrap: wrap;
}

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  background: var(--gradient-primary);
  color: white;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
  box-shadow: 0 4px 18px rgba(99, 102, 241, 0.3);
}

.btn-download:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(99, 102, 241, 0.42);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  background: transparent;
  color: var(--gray-600);
  font-size: 15px;
  font-weight: 600;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
}

.btn-secondary:hover {
  border-color: var(--gray-300);
  color: var(--gray-800);
  background: var(--gray-50);
  transform: translateY(-1px);
}

/* ============================================
   Features Section
   ============================================ */
.features-section {
  padding: 100px 0;
  background: var(--gray-50);
}

.features-header {
  text-align: center;
  max-width: 560px;
  margin: 0 auto 64px;
}

.features-header h2 {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 750;
  color: var(--gray-900);
  letter-spacing: -0.8px;
  margin-bottom: 16px;
}

.features-header p {
  font-size: 17px;
  color: var(--gray-500);
  line-height: 1.6;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  max-width: 1100px;
  margin: 0 auto;
}

.feature-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 38px 30px;
  text-align: center;
  transition: all var(--transition-base);
  border: 1px solid var(--gray-100);
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
  border-color: transparent;
}

.feature-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 22px;
  background: linear-gradient(135deg, var(--primary-50), var(--secondary-50));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary-500);
  font-size: 28px;
  transition: all var(--transition-base);
}

.feature-card:hover .feature-icon {
  background: var(--gradient-primary);
  color: white;
  transform: scale(1.08);
  box-shadow: 0 8px 24px rgba(99, 102, 241, 0.25);
}

.feature-card h3 {
  font-size: 19px;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 10px;
  letter-spacing: -0.3px;
}

.feature-card p {
  font-size: 14px;
  color: var(--gray-500);
  line-height: 1.6;
}

/* ============================================
   Footer
   ============================================ */
.footer {
  background: var(--gray-900);
  color: var(--gray-400);
  padding: 72px 0 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  max-width: 1100px;
  margin: 0 auto 48px;
  padding: 0 24px;
}

.footer-brand p {
  font-size: 14px;
  line-height: 1.7;
  margin-top: 16px;
  color: var(--gray-500);
}

.footer-col h4 {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--gray-300);
  margin-bottom: 20px;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links a {
  font-size: 14px;
  color: var(--gray-500);
  transition: all var(--transition-fast);
}

.footer-links a:hover {
  color: var(--white);
  padding-left: 4px;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding-top: 24px;
  text-align: center;
  font-size: 13px;
  color: var(--gray-600);
  max-width: 1100px;
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

.footer-bottom a {
  color: var(--primary-400);
}

.footer-bottom a:hover {
  color: var(--primary-300);
}

/* ============================================
   Toast Notification
   ============================================ */
.toast-container {
  position: fixed;
  top: 90px;
  right: 24px;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 10px;
  pointer-events: none;
}

.toast {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 20px;
  background: var(--white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-xl);
  font-size: 14px;
  font-weight: 500;
  color: var(--gray-700);
  min-width: 300px;
  max-width: 420px;
  pointer-events: auto;
  animation: slideInRight 0.35s ease-out;
  border-left: 4px solid var(--primary-500);
}

.toast.success { border-left-color: var(--success); }
.toast.error { border-left-color: var(--error); }
.toast.warning { border-left-color: var(--warning); }

.toast-icon {
  flex-shrink: 0;
  font-size: 18px;
}

.toast-message { flex: 1; }

.toast-close {
  flex-shrink: 0;
  color: var(--gray-400);
  font-size: 18px;
  cursor: pointer;
  padding: 2px;
  transition: color var(--transition-fast);
}

.toast-close:hover { color: var(--gray-700); }

.toast.hiding {
  animation: fadeOutRight 0.3s ease-in forwards;
}

@keyframes fadeOutRight {
  to {
    opacity: 0;
    transform: translateX(30px);
  }
}

/* ============================================
   Modal / Upgrade Prompt
   ============================================ */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(17, 24, 39, 0.6);
  backdrop-filter: blur(4px);
  z-index: 10000;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.modal-overlay.active {
  display: flex;
  animation: fadeIn 0.2s ease-out;
}

.modal-card {
  background: var(--white);
  border-radius: var(--radius-xl);
  padding: 44px 40px;
  max-width: 480px;
  width: 100%;
  text-align: center;
  animation: bounce-in 0.35s ease-out;
  box-shadow: 0 24px 48px rgba(0, 0, 0, 0.15);
}

.modal-icon {
  width: 68px;
  height: 68px;
  margin: 0 auto 24px;
  background: linear-gradient(135deg, var(--primary-50), var(--secondary-50));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 30px;
}

.modal-card h3 {
  font-size: 22px;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 12px;
  letter-spacing: -0.3px;
}

.modal-card p {
  font-size: 15px;
  color: var(--gray-500);
  line-height: 1.6;
  margin-bottom: 28px;
}

.modal-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.modal-actions .btn-download {
  font-size: 14px;
  padding: 12px 26px;
}

/* ============================================
   Responsive Design
   ============================================ */

/* Tablet */
@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr;
    gap: 32px;
  }
}

/* Mobile */
@media (max-width: 768px) {
  :root {
    --nav-height: 64px;
  }

  .container {
    padding: 0 16px;
  }

  .nav-links, .nav-cta {
    display: none !important;
  }

  .nav-toggle {
    display: flex;
  }

  .mobile-menu.open {
    display: block;
  }

  .hero-section {
    padding-top: calc(var(--nav-height) + 36px);
    padding-bottom: 24px;
  }

  .hero-title {
    font-size: clamp(28px, 7vw, 40px);
    letter-spacing: -0.8px;
  }

  .hero-subtitle {
    font-size: 15px;
  }

  .hero-stats {
    gap: 20px;
  }

  .hero-stat-value {
    font-size: 22px;
  }

  .upload-zone-content {
    padding: 40px 24px;
    min-height: 280px;
  }

  .upload-icon-wrapper {
    width: 72px;
    height: 72px;
  }

  .upload-icon {
    width: 72px;
    height: 72px;
  }

  .upload-title {
    font-size: 17px;
  }

  .upload-subtitle {
    font-size: 14px;
  }

  .features-section {
    padding: 60px 0;
  }

  .features-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .feature-card {
    padding: 28px 24px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .result-actions {
    flex-direction: column;
    width: 100%;
  }

  .result-actions .btn-download,
  .result-actions .btn-secondary {
    justify-content: center;
    width: 100%;
  }

  .comparison-container {
    aspect-ratio: 4/3;
  }

  .toast-container {
    top: 76px;
    right: 12px;
    left: 12px;
  }

  .toast {
    min-width: unset;
    max-width: unset;
    width: 100%;
  }

  .modal-card {
    padding: 32px 24px;
  }

  .modal-actions {
    flex-direction: column;
  }

  .wave-separator svg {
    height: 36px;
  }
}

@media (max-width: 480px) {
  .hero-stats {
    flex-direction: column;
    gap: 16px;
  }
}