:root {
  --primary: #ff9800;
  --primary-hover: #ffb74d;
  --primary-dark: #e68900;
  --bg-dark: #0d0d0f;
  --bg-card: #1a1a1f;
  --bg-card-hover: #222228;
  --text-primary: #ffffff;
  --text-secondary: #a0a0a8;
  --text-muted: #6b6b75;
  --border: #2a2a32;
  --accent-blue: #4a9eff;
  --gradient-primary: linear-gradient(135deg, #ff9800 0%, #ff6d00 100%);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.4);
  --radius: 12px;
  --radius-sm: 8px;
  --header-height: 64px;
  --max-width: 1200px;
  --page-padding: 24px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.7;
  min-height: 100vh;
}

a {
  color: var(--accent-blue);
  text-decoration: none;
  transition: color 0.2s;
}

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

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--page-padding);
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(13, 13, 15, 0.98);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  min-height: var(--header-height);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-link img {
  width: 44px;
  height: 44px;
  border-radius: 10px;
}

.logo-text {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.logo-text span {
  color: var(--primary);
}

.nav-desktop {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-desktop a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
}

.nav-desktop a:hover,
.nav-desktop a.active {
  color: var(--primary);
}

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 24px;
  background: var(--gradient-primary);
  color: #fff !important;
  border-radius: 24px;
  font-weight: 600;
  font-size: 0.95rem;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  white-space: nowrap;
}

.btn-download:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255, 152, 0, 0.4);
  color: #fff !important;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 8px;
}

.nav-mobile {
  display: none;
  flex-direction: column;
  padding: 8px 0 16px;
  border-top: 1px solid var(--border);
  background: var(--bg-dark);
}

.nav-mobile.open {
  display: flex;
}

.nav-mobile a {
  display: block;
  padding: 12px var(--page-padding);
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border);
}

.nav-mobile a:last-child {
  border-bottom: none;
}

/* Hero */
.hero {
  padding: 60px 0 80px;
  background: radial-gradient(ellipse at 50% 0%, rgba(255, 152, 0, 0.12) 0%, transparent 60%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.hero-content h1 {
  font-size: 2.5rem;
  line-height: 1.3;
  margin-bottom: 20px;
  font-weight: 800;
}

.hero-content h1 em {
  color: var(--primary);
  font-style: normal;
}

.hero-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 24px;
  background: var(--bg-card);
  color: var(--text-primary) !important;
  border: 1px solid var(--border);
  border-radius: 24px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: border-color 0.2s, background 0.2s;
}

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

.hero-phone {
  display: flex;
  justify-content: center;
}

.phone-frame {
  width: 280px;
  border-radius: 32px;
  overflow: hidden;
  border: 3px solid var(--border);
  box-shadow: var(--shadow-card), 0 0 60px rgba(255, 152, 0, 0.15);
}

/* Sections */
.section {
  padding: 64px 0;
}

.section-alt {
  background: rgba(26, 26, 31, 0.5);
}

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-header h2 {
  font-size: 2rem;
  margin-bottom: 12px;
  font-weight: 700;
}

.section-header p {
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* Feature cards */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: transform 0.2s, border-color 0.2s;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: rgba(255, 152, 0, 0.3);
}

.feature-icon {
  width: 48px;
  height: 48px;
  background: rgba(255, 152, 0, 0.15);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 1.15rem;
  margin-bottom: 10px;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* Screenshot gallery */
.screenshot-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.screenshot-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform 0.2s;
}

.screenshot-item:hover {
  transform: scale(1.03);
}

.screenshot-item img {
  width: 100%;
  aspect-ratio: 9/16;
  object-fit: cover;
}

.screenshot-caption {
  padding: 12px 14px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  text-align: center;
}

/* Module tabs showcase */
.module-showcase {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
  margin-bottom: 48px;
}

.module-showcase:nth-child(even) {
  direction: rtl;
}

.module-showcase:nth-child(even) > * {
  direction: ltr;
}

.module-showcase img {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
}

.module-info h3 {
  font-size: 1.5rem;
  margin-bottom: 12px;
  color: var(--primary);
}

.module-info p {
  color: var(--text-secondary);
  margin-bottom: 16px;
}

.module-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  padding: 4px 12px;
  background: rgba(74, 158, 255, 0.12);
  color: var(--accent-blue);
  border-radius: 16px;
  font-size: 0.8rem;
}

/* SEO content */
.seo-content {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px;
}

.seo-content h2 {
  font-size: 1.5rem;
  margin: 32px 0 16px;
  color: var(--primary);
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.seo-content h2:first-child {
  margin-top: 0;
}

.seo-content h3 {
  font-size: 1.2rem;
  margin: 24px 0 12px;
}

.seo-content p {
  color: var(--text-secondary);
  margin-bottom: 16px;
  text-align: justify;
}

.seo-content ul,
.seo-content ol {
  color: var(--text-secondary);
  margin: 0 0 16px 24px;
}

.seo-content li {
  margin-bottom: 8px;
}

.seo-content a {
  color: var(--accent-blue);
}

/* FAQ */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 20px 24px;
}

.faq-item h3 {
  font-size: 1rem;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.faq-item p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* Download CTA */
.cta-section {
  text-align: center;
  padding: 80px 0;
  background: radial-gradient(ellipse at 50% 100%, rgba(255, 152, 0, 0.15) 0%, transparent 60%);
}

.cta-section h2 {
  font-size: 2rem;
  margin-bottom: 16px;
}

.cta-section p {
  color: var(--text-secondary);
  margin-bottom: 32px;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

/* Page content (sub pages) */
.page-hero {
  padding: 48px 0 32px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 40px;
}

.page-hero h1 {
  font-size: 2rem;
  margin-bottom: 8px;
}

.page-hero .breadcrumb {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.page-hero .breadcrumb a {
  color: var(--text-secondary);
}

.page-content {
  padding-bottom: 64px;
}

.page-content h2 {
  font-size: 1.35rem;
  margin: 32px 0 14px;
  color: var(--primary);
}

.page-content h3 {
  font-size: 1.1rem;
  margin: 24px 0 10px;
}

.page-content p {
  color: var(--text-secondary);
  margin-bottom: 14px;
}

.page-content ul,
.page-content ol {
  color: var(--text-secondary);
  margin: 0 0 14px 24px;
}

.page-content li {
  margin-bottom: 6px;
}

/* Error pages */
.error-page {
  min-height: calc(100vh - var(--header-height) - 200px);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 60px 24px;
}

.error-code {
  font-size: 6rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
  margin-bottom: 16px;
}

.error-page h1 {
  font-size: 1.5rem;
  margin-bottom: 12px;
}

.error-page p {
  color: var(--text-secondary);
  margin-bottom: 32px;
}

/* Footer */
.site-footer {
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  padding: 48px 0 24px;
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand img {
  width: 48px;
  border-radius: 10px;
  margin-bottom: 16px;
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
}

.footer-col h4 {
  font-size: 0.95rem;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 10px;
}

.footer-col a {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

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

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

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

.footer-links {
  display: flex;
  gap: 20px;
}

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

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

  .screenshot-grid {
    grid-template-columns: repeat(3, 1fr);
  }

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

@media (max-width: 768px) {
  :root {
    --page-padding: 16px;
    --header-height: 56px;
  }

  .nav-desktop {
    display: none;
  }

  .menu-toggle {
    display: block;
  }

  .hero {
    padding: 40px 0 48px;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: 32px;
    text-align: center;
  }

  .hero-content h1 {
    font-size: 1.75rem;
  }

  .hero-badges,
  .hero-actions {
    justify-content: center;
  }

  .hero-phone {
    order: -1;
  }

  .phone-frame {
    width: 220px;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .screenshot-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .module-showcase {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .module-showcase:nth-child(even) {
    direction: ltr;
  }

  .seo-content {
    padding: 24px 20px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

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

  .section-header h2 {
    font-size: 1.5rem;
  }
}

@media (max-width: 480px) {
  .hero-content h1 {
    font-size: 1.5rem;
  }

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

  .screenshot-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}