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

:root {
  --primary: #7c3aed;
  --primary-hover: #6d28d9;
  --primary-light: #ede9fe;
  --primary-50: #f5f3ff;
  --text: #1e1b4b;
  --text-secondary: #6b7280;
  --bg: #ffffff;
  --bg-section: #faf9fe;
  --border: #e5e7eb;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 25px rgba(124, 58, 237, 0.1), 0 4px 10px rgba(0, 0, 0, 0.04);
}

body {
  font-family: 'Noto Sans SC', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

html[lang="en"] body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

a {
  color: inherit;
  text-decoration: none;
}

/* ==================== Navbar ==================== */

.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.navbar-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 18px;
  color: var(--primary);
}

.nav-links {
  display: flex;
  gap: 32px;
}

.nav-links a {
  font-size: 14px;
  color: var(--text-secondary);
  font-weight: 500;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--primary);
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.lang-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border: 1.5px solid var(--border);
  border-radius: 100px;
  background: #fff;
  color: var(--text);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: all 0.2s;
}

.lang-toggle:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-50);
}

.lang-toggle svg {
  flex-shrink: 0;
  opacity: 0.6;
}

.lang-label {
  line-height: 1;
}

/* ==================== Breadcrumb ==================== */

.breadcrumb {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text-secondary);
}

.breadcrumb a {
  color: var(--text-secondary);
  transition: color 0.2s;
}

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

.breadcrumb svg {
  flex-shrink: 0;
  opacity: 0.4;
}

.breadcrumb span {
  color: var(--text);
  font-weight: 500;
}

/* ==================== Hero ==================== */

.hero {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 24px 32px;
}

.hero-content {
  display: flex;
  align-items: center;
  gap: 64px;
  background: linear-gradient(135deg, var(--primary-50) 0%, #f0ebff 100%);
  border-radius: 20px;
  padding: 48px 56px;
}

.hero-image {
  flex-shrink: 0;
}

.hero-text {
  flex: 1;
}

.hero-text h1 {
  font-size: 36px;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 16px;
  color: var(--text);
}

.hero-desc {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 32px;
}

.upload-area {
  border: 2px dashed #c4b5fd;
  border-radius: var(--radius);
  padding: 32px;
  text-align: center;
  background: rgba(255, 255, 255, 0.7);
  transition: all 0.3s;
  cursor: pointer;
}

.upload-area:hover,
.upload-area.dragover {
  border-color: var(--primary);
  background: rgba(255, 255, 255, 0.95);
  box-shadow: var(--shadow-lg);
}

.upload-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}

.upload-btn:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(124, 58, 237, 0.3);
}

.upload-hint {
  margin-top: 12px;
  font-size: 13px;
  color: var(--text-secondary);
}

.upload-note {
  text-align: center;
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 16px;
  opacity: 0.7;
}

/* ==================== Converter ==================== */

.converter-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px 48px;
  display: none;
}

.converter-section.active {
  display: block;
}

.converter-container {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px;
  box-shadow: var(--shadow);
}

.converter-container h2 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 20px;
}

.file-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.file-item {
  position: relative;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: #f9fafb;
  cursor: grab;
  transition: box-shadow 0.2s;
}

.file-item:hover {
  box-shadow: var(--shadow-lg);
}

.file-item.dragging {
  opacity: 0.5;
  cursor: grabbing;
}

.file-item img {
  width: 100%;
  height: 120px;
  object-fit: cover;
  display: block;
}

.file-item-info {
  padding: 8px 10px;
  font-size: 11px;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.file-item-remove {
  position: absolute;
  top: 6px;
  right: 6px;
  width: 24px;
  height: 24px;
  background: rgba(0, 0, 0, 0.5);
  border: none;
  border-radius: 50%;
  color: #fff;
  font-size: 14px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity 0.2s;
}

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

.converter-options {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  margin-bottom: 24px;
  padding: 20px;
  background: var(--bg-section);
  border-radius: var(--radius-sm);
}

.option-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.option-group label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
}

.radio-group {
  display: flex;
  gap: 16px;
}

.radio-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  cursor: pointer;
  color: var(--text-secondary);
}

.radio-label input[type="radio"] {
  accent-color: var(--primary);
}

select {
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  font-family: inherit;
  background: #fff;
  color: var(--text);
  cursor: pointer;
  min-width: 140px;
}

select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.1);
}

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

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 36px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}

.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(124, 58, 237, 0.3);
}

.btn-primary:disabled {
  background: #d1d5db;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 24px;
  background: #fff;
  color: var(--primary);
  border: 2px solid var(--primary);
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}

.btn-secondary:hover {
  background: var(--primary-50);
}

.progress-bar {
  margin-top: 20px;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
  display: none;
}

.progress-bar.active {
  display: block;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), #a78bfa);
  border-radius: 3px;
  width: 0%;
  transition: width 0.3s;
}

/* ==================== Steps ==================== */

.steps-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 80px 24px;
}

.steps-section h2 {
  text-align: center;
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 48px;
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.step-card {
  text-align: center;
  padding: 40px 28px;
  border-radius: 16px;
  background: var(--bg);
  border: 1px solid var(--border);
  transition: all 0.3s;
}

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

.step-icon {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
}

.step-icon-1 {
  background: #ede9fe;
  color: var(--primary);
}

.step-icon-2 {
  background: #dbeafe;
  color: #2563eb;
}

.step-icon-3 {
  background: #d1fae5;
  color: #059669;
}

.step-card h4 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 12px;
}

.step-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ==================== Feature Sections ==================== */

.feature-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px 80px;
}

.feature-row {
  display: flex;
  align-items: center;
  gap: 64px;
  margin-bottom: 64px;
}

.feature-row.reverse {
  flex-direction: row-reverse;
}

.feature-text {
  flex: 1;
}

.feature-text h2 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 16px;
  line-height: 1.4;
}

.feature-text p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
}

.feature-visual {
  flex-shrink: 0;
  width: 340px;
  height: 240px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.visual-card {
  width: 100%;
  height: 100%;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
}

.visual-card-1 {
  background: linear-gradient(135deg, #ede9fe, #ddd6fe);
}

.mini-img {
  width: 80px;
  height: 80px;
  border-radius: 8px;
  background: linear-gradient(135deg, #a78bfa, #7c3aed);
}

.mini-arrow {
  font-size: 32px;
  color: var(--primary);
  font-weight: 700;
}

.mini-pdf {
  width: 80px;
  height: 80px;
  border-radius: 8px;
  background: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 20px;
  color: #dc2626;
  box-shadow: var(--shadow);
}

.visual-card-2 {
  background: linear-gradient(135deg, #dbeafe, #bfdbfe);
}

.share-icons {
  display: flex;
  gap: 24px;
}

.share-icon {
  width: 64px;
  height: 64px;
  background: rgba(255, 255, 255, 0.8);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  box-shadow: var(--shadow);
}

.visual-card-3 {
  background: linear-gradient(135deg, #d1fae5, #a7f3d0);
}

.batch-demo {
  display: flex;
  align-items: center;
  gap: 8px;
}

.batch-item {
  width: 48px;
  height: 60px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #059669;
  box-shadow: var(--shadow);
  font-size: 16px;
}

.batch-combine {
  font-size: 24px;
  color: #059669;
  font-weight: 700;
  margin: 0 4px;
}

.batch-result {
  width: 64px;
  height: 80px;
  border-radius: 8px;
  background: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 18px;
  color: #dc2626;
  box-shadow: var(--shadow);
}

/* ==================== How-to ==================== */

.howto-section {
  background: var(--bg-section);
  padding: 80px 24px;
}

.howto-section h2 {
  text-align: center;
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 48px;
}

.howto-content {
  max-width: 1000px;
  margin: 0 auto;
  display: flex;
  gap: 48px;
  align-items: flex-start;
}

.howto-visual {
  flex-shrink: 0;
}

.howto-accordion {
  flex: 1;
}

.accordion-item {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  overflow: hidden;
  transition: box-shadow 0.2s;
}

.accordion-item.active {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.08);
}

.accordion-header {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  background: none;
  border: none;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  color: var(--text);
}

.accordion-number {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
  flex-shrink: 0;
}

.accordion-arrow {
  margin-left: auto;
  transition: transform 0.3s;
  color: var(--text-secondary);
}

.accordion-item.active .accordion-arrow {
  transform: rotate(180deg);
}

.accordion-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
}

.accordion-item.active .accordion-body {
  max-height: 200px;
  padding: 0 20px 16px 60px;
}

.accordion-body p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* ==================== FAQ ==================== */

.faq-section {
  max-width: 800px;
  margin: 0 auto;
  padding: 80px 24px;
}

.faq-section h2 {
  text-align: center;
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 40px;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.faq-item {
  border-bottom: 1px solid var(--border);
}

.faq-item:first-child {
  border-top: 1px solid var(--border);
}

.faq-header {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 0;
  background: none;
  border: none;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  color: var(--text);
  text-align: left;
}

.faq-header:hover {
  color: var(--primary);
}

.faq-arrow {
  flex-shrink: 0;
  transition: transform 0.3s;
  color: var(--text-secondary);
}

.faq-item.active .faq-arrow {
  transform: rotate(180deg);
}

.faq-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
}

.faq-item.active .faq-body {
  max-height: 300px;
  padding-bottom: 20px;
}

.faq-body p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* ==================== Explore ==================== */

.explore-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px 80px;
  text-align: center;
}

.explore-section h2 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 32px;
}

.explore-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

.explore-tag {
  padding: 10px 24px;
  border: 1px solid var(--border);
  border-radius: 100px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  transition: all 0.2s;
}

.explore-tag:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-50);
}

/* ==================== Footer ==================== */

.footer {
  background: #1e1b4b;
  color: #e0e7ff;
  padding: 64px 24px 0;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  gap: 80px;
  padding-bottom: 48px;
}

.footer-brand {
  flex: 1;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 18px;
  color: #fff;
  margin-bottom: 12px;
}

.footer-desc {
  font-size: 14px;
  color: #a5b4fc;
  line-height: 1.7;
  max-width: 320px;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-col h4 {
  font-size: 14px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 4px;
}

.footer-col a {
  font-size: 13px;
  color: #a5b4fc;
  transition: color 0.2s;
}

.footer-col a:hover {
  color: #fff;
}

.footer-bottom {
  border-top: 1px solid #312e81;
  padding: 20px 0;
  text-align: center;
}

.footer-bottom p {
  font-size: 12px;
  color: #6366f1;
}

/* ==================== Toast ==================== */

.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: #1e1b4b;
  color: #fff;
  padding: 14px 28px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  z-index: 1000;
  opacity: 0;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ==================== Ad Slots ==================== */

.ad-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
}

.ad-container ins {
  background: #f9fafb;
  border: 1px dashed #d1d5db;
  border-radius: var(--radius-sm);
  min-height: 90px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.ad-container ins::after {
  content: 'Ad';
  color: #9ca3af;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 1px;
}

.ad-label {
  display: block;
  text-align: center;
  font-size: 10px;
  color: #9ca3af;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-top: 4px;
}

.ad-hero {
  margin-top: -16px;
  margin-bottom: 16px;
}

.ad-mid {
  padding-top: 16px;
  padding-bottom: 16px;
}

.ad-between {
  padding-top: 16px;
  padding-bottom: 16px;
}

.ad-footer {
  padding-top: 32px;
  padding-bottom: 32px;
}

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

@media (max-width: 768px) {
  .hero-content {
    flex-direction: column;
    padding: 32px 24px;
    gap: 32px;
  }

  .hero-image {
    display: none;
  }

  .hero-text h1 {
    font-size: 28px;
  }

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

  .feature-row,
  .feature-row.reverse {
    flex-direction: column;
    gap: 32px;
  }

  .feature-visual {
    width: 100%;
    height: 180px;
  }

  .howto-content {
    flex-direction: column;
  }

  .howto-visual {
    display: none;
  }

  .footer-inner {
    flex-direction: column;
    gap: 40px;
  }

  .converter-options {
    flex-direction: column;
  }

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

  .nav-links {
    display: none;
  }

  .navbar-inner {
    gap: 8px;
  }

  .file-list {
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  }
}