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

:root {
  --bg: #f8f9fa;
  --surface: #ffffff;
  --surface-alt: #f1f3f5;
  --text: #1a1a2e;
  --text-muted: #6b7280;
  --text-light: #9ca3af;

  --grad-start: #6C7BF2;
  --grad-mid: #9B6FE0;
  --grad-end: #E8729E;
  --grad: linear-gradient(135deg, var(--grad-start), var(--grad-mid), var(--grad-end));

  --accent: #6C7BF2;
  --accent-soft: rgba(108, 123, 242, 0.12);
  --danger: #ef4444;
  --danger-soft: rgba(239, 68, 68, 0.1);
  --success: #22c55e;

  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.12);
  --shadow-glow: 0 0 24px rgba(108,123,242,0.25);

  --font: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.container {
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(248, 249, 250, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.feather-logo {
  filter: drop-shadow(0 0 6px rgba(108, 123, 242, 0.5));
  transition: filter var(--transition);
  animation: featherPulse 3s ease-in-out infinite;
}

@keyframes featherPulse {
  0%, 100% { filter: drop-shadow(0 0 6px rgba(108, 123, 242, 0.5)); }
  50% { filter: drop-shadow(0 0 12px rgba(155, 111, 224, 0.65)); }
}

.brand-name {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  background: var(--grad);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

.credit-badge {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 5px 12px;
  border-radius: 100px;
  white-space: nowrap;
}

.credit-badge svg {
  color: var(--grad-mid);
}

.credit-badge.low {
  color: #e85d04;
  background: rgba(232, 93, 4, 0.1);
}

.privacy-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--success);
  background: rgba(34, 197, 94, 0.1);
  padding: 6px 14px;
  border-radius: 100px;
}

/* ===== Hero ===== */
.hero {
  text-align: center;
  padding: 56px 20px 32px;
}

.hero-title {
  font-size: clamp(1.8rem, 5vw, 2.8rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
}

.grad-text {
  background: var(--grad);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 580px;
  margin: 0 auto;
}

/* ===== Main App ===== */
.app-main {
  flex: 1;
  padding-bottom: 48px;
}

/* ===== Upload Area ===== */
.upload-area {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* ===== Drop Zone ===== */
.drop-zone {
  background: var(--surface);
  border: 2.5px dashed #d1d5db;
  border-radius: var(--radius-lg);
  padding: 40px 24px;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition);
  box-shadow: var(--shadow-sm);
}

.drop-zone:hover,
.drop-zone:focus-visible {
  border-color: var(--accent);
  background: var(--accent-soft);
  box-shadow: var(--shadow-md);
  outline: none;
}

.drop-zone.dragover {
  border-color: var(--grad-mid);
  background: rgba(155, 111, 224, 0.08);
  box-shadow: var(--shadow-glow);
  transform: scale(1.01);
}

.drop-zone-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.upload-icon {
  color: var(--accent);
  opacity: 0.7;
  transition: transform var(--transition);
}

.drop-zone:hover .upload-icon {
  transform: translateY(-4px);
}

.drop-zone-title {
  font-size: 1.15rem;
  font-weight: 600;
}

.drop-zone-hint {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ===== Dual Upload Buttons ===== */
.upload-buttons {
  display: flex;
  gap: 16px;
}

.upload-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 16px 20px;
  font-family: var(--font);
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition);
}

.gallery-btn {
  color: #fff;
  background: var(--grad);
  box-shadow: 0 4px 14px rgba(108, 123, 242, 0.3);
}

.gallery-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(108, 123, 242, 0.4);
}

.camera-btn {
  color: var(--text);
  background: var(--surface);
  border: 2px solid #e0e0e0;
  box-shadow: var(--shadow-sm);
}

.camera-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

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

/* ===== Preview Section ===== */
.preview-section {
  margin-top: 32px;
  animation: fadeInUp 0.4s ease;
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.section-title {
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.image-count {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  background: var(--surface-alt);
  padding: 4px 14px;
  border-radius: 100px;
}

.preview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 16px;
}

.preview-item {
  position: relative;
  background: var(--surface);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  cursor: grab;
  border: 2px solid transparent;
}

.preview-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.preview-item.dragging {
  opacity: 0.4;
  cursor: grabbing;
}

.preview-item.drag-over {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.preview-thumb {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  display: block;
  pointer-events: none;
}

.preview-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0,0,0,0.55), transparent 60%);
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  padding: 8px;
  opacity: 0;
  transition: opacity var(--transition);
}

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

.cam-badge {
  position: absolute;
  top: 6px;
  left: 6px;
  font-size: 0.65rem;
  font-weight: 700;
  color: #fff;
  background: var(--grad);
  padding: 2px 8px;
  border-radius: 100px;
  z-index: 2;
}

.preview-page-num {
  font-size: 0.75rem;
  font-weight: 600;
  color: #fff;
  background: rgba(0,0,0,0.4);
  padding: 2px 8px;
  border-radius: 100px;
  backdrop-filter: blur(4px);
}

.preview-actions {
  display: flex;
  gap: 4px;
}

.preview-btn {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255,255,255,0.9);
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: all var(--transition);
  color: var(--text);
}

.preview-btn:hover {
  background: #fff;
  transform: scale(1.1);
}

.preview-btn.remove-btn {
  color: var(--danger);
}

.preview-btn.remove-btn:hover {
  background: var(--danger);
  color: #fff;
}

.preview-btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

/* Always-visible controls on mobile */
@media (max-width: 640px) {
  .preview-overlay {
    opacity: 1;
    background: linear-gradient(to top, rgba(0,0,0,0.5), transparent 80%);
  }
}

/* ===== Doc Name Input ===== */
.doc-name-group {
  margin-bottom: 24px;
}

.doc-name-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 8px;
}

.doc-name-input {
  width: 100%;
  padding: 12px 16px;
  font-family: var(--font);
  font-size: 0.95rem;
  color: var(--text);
  background: var(--surface-alt);
  border: 2px solid transparent;
  border-radius: var(--radius-sm);
  outline: none;
  transition: all var(--transition);
}

.doc-name-input:focus {
  border-color: var(--accent);
  background: var(--surface);
}

/* ===== Scan Filter Dropdown ===== */
.filter-group {
  margin-bottom: 24px;
}

.filter-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 8px;
}

.filter-select-wrapper {
  position: relative;
}

.filter-select {
  width: 100%;
  padding: 12px 40px 12px 16px;
  font-family: var(--font);
  font-size: 0.95rem;
  color: var(--text);
  background: var(--surface-alt);
  border: 2px solid transparent;
  border-radius: var(--radius-sm);
  outline: none;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  transition: all var(--transition);
}

.filter-select:focus {
  border-color: var(--accent);
  background: var(--surface);
}

.filter-chevron {
  position: absolute;
  right: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

.filter-hint {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-top: 6px;
}

/* ===== Settings Section ===== */
.settings-section {
  margin-top: 32px;
  animation: fadeInUp 0.4s ease;
}

.settings-card {
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-md);
}

.settings-hint {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-top: 4px;
  margin-bottom: 24px;
}

.slider-wrapper {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.slider-labels {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
}

.quality-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 8px;
  border-radius: 100px;
  background: var(--grad);
  outline: none;
  cursor: pointer;
}

.quality-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: #fff;
  border: 3px solid var(--accent);
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
  transition: transform var(--transition);
}

.quality-slider::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

.quality-slider::-moz-range-thumb {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: #fff;
  border: 3px solid var(--accent);
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

.quality-readout {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

.quality-label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent);
}

.quality-value {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text);
  background: var(--surface-alt);
  padding: 2px 10px;
  border-radius: 100px;
}

/* ===== Action Bar ===== */
.action-bar {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  margin-top: 28px;
}

.progress-container {
  width: 100%;
  max-width: 500px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.progress-track {
  width: 100%;
  height: 10px;
  background: var(--surface-alt);
  border-radius: 100px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: var(--grad);
  border-radius: 100px;
  transition: width 0.3s ease;
}

.progress-text {
  text-align: center;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}

.generate-btn {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 16px 40px;
  font-family: var(--font);
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
  background: var(--grad);
  background-size: 200% 100%;
  border: none;
  border-radius: 100px;
  cursor: pointer;
  transition: all var(--transition);
  box-shadow: 0 6px 24px rgba(108, 123, 242, 0.35);
}

.generate-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 32px rgba(108, 123, 242, 0.45);
  background-position: 100% 0;
}

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

.generate-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.clear-btn {
  padding: 10px 24px;
  font-family: var(--font);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
  background: transparent;
  border: 1.5px solid #e0e0e0;
  border-radius: 100px;
  cursor: pointer;
  transition: all var(--transition);
}

.clear-btn:hover {
  color: var(--danger);
  border-color: var(--danger);
  background: var(--danger-soft);
}

/* ===== Features Strip ===== */
.features-strip {
  background: var(--surface);
  padding: 48px 0;
  margin-top: auto;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  text-align: center;
  padding: 24px 16px;
}

.feature-icon {
  width: 52px;
  height: 52px;
  margin: 0 auto 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
}

.icon-private { background: rgba(34,197,94,0.12); color: var(--success); }
.icon-fast { background: rgba(108,123,242,0.12); color: var(--accent); }
.icon-rearrange { background: rgba(232,114,158,0.12); color: var(--grad-end); }

.feature-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.feature-card p {
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* ===== Footer ===== */
.site-footer {
  background: var(--surface);
  border-top: 1px solid rgba(0,0,0,0.05);
  padding: 24px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.footer-brand {
  font-weight: 700;
  font-size: 1rem;
  background: var(--grad);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.footer-credit {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-credit strong {
  color: var(--text);
  font-weight: 700;
}

/* ===== Modal & Ad Overlay ===== */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  animation: fadeIn 0.2s ease;
}

.modal-card {
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  max-width: 400px;
  width: 100%;
  text-align: center;
  box-shadow: var(--shadow-lg);
  animation: scaleIn 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.modal-icon {
  width: 72px;
  height: 72px;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: 50%;
}

.modal-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.modal-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 24px;
  line-height: 1.5;
}

.modal-desc strong {
  color: var(--text);
}

.modal-primary-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  padding: 14px;
  font-family: var(--font);
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  background: var(--grad);
  border: none;
  border-radius: 100px;
  cursor: pointer;
  transition: all var(--transition);
  box-shadow: 0 4px 16px rgba(108, 123, 242, 0.35);
  margin-bottom: 10px;
}

.modal-primary-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(108, 123, 242, 0.45);
}

.modal-primary-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.modal-secondary-btn {
  width: 100%;
  padding: 10px;
  font-family: var(--font);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
  background: transparent;
  border: none;
  border-radius: 100px;
  cursor: pointer;
  transition: color var(--transition);
}

.modal-secondary-btn:hover {
  color: var(--text);
}

/* Ad watching overlay */
.ad-overlay {
  position: fixed;
  inset: 0;
  z-index: 1100;
  background: rgba(26, 26, 46, 0.95);
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.2s ease;
}

.ad-overlay-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.ad-spinner-ring {
  width: 60px;
  height: 60px;
  border: 4px solid rgba(255, 255, 255, 0.2);
  border-top-color: var(--grad-mid);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.ad-overlay-text {
  font-size: 1.1rem;
  font-weight: 600;
  color: #fff;
}

.ad-countdown {
  font-size: 2.5rem;
  font-weight: 700;
  background: var(--grad);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.ad-overlay-sub {
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.5);
}

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

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

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

/* ===== Utilities & Animations ===== */
.hidden {
  display: none !important;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .features-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .footer-inner {
    flex-direction: column;
    gap: 8px;
    text-align: center;
  }
}

@media (max-width: 640px) {
  .hero {
    padding: 36px 20px 24px;
  }

  .drop-zone {
    padding: 28px 16px;
  }

  .upload-buttons {
    flex-direction: column;
    gap: 12px;
  }

  .preview-grid {
    grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
    gap: 12px;
  }

  .settings-card {
    padding: 20px;
  }

  .generate-btn {
    width: 100%;
    justify-content: center;
    padding: 14px 24px;
    font-size: 1rem;
  }

  .privacy-badge {
    display: none;
  }

  .credit-badge {
    font-size: 0.72rem;
    padding: 4px 10px;
  }

  .brand-name {
    font-size: 1.2rem;
  }

  .header-inner {
    height: 56px;
  }
}

@media (max-width: 400px) {
  .preview-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}