/* Subtle grid pattern */
    .bg-pattern {
      position: fixed;
      inset: 0;
      background-image: 
        linear-gradient(rgba(0,0,0,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0,0,0,0.03) 1px, transparent 1px);
      background-size: 40px 40px;
      pointer-events: none;
    }
    
    /* Gradient orbs */
    .gradient-orb {
      position: fixed;
      border-radius: 50%;
      filter: blur(100px);
      pointer-events: none;
      opacity: 0.5;
    }
    
    .orb-1 {
      width: 700px;
      height: 700px;
      background: linear-gradient(135deg, rgba(0, 0, 0, 0.06), rgba(0, 0, 0, 0.02));
      top: -250px;
      right: -150px;
    }
    
    .orb-2 {
      width: 600px;
      height: 600px;
      background: linear-gradient(135deg, rgba(220, 38, 38, 0.08), rgba(220, 38, 38, 0.02));
      bottom: 10%;
      left: -200px;
    }
    
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 20px;
      border-radius: 10px;
      font-size: 14px;
      font-weight: 600;
      text-decoration: none;
      transition: all 0.2s;
      cursor: pointer;
      border: none;
    }
    
    .btn-primary {
      background: var(--accent);
      color: white;
    }
    
    .btn-primary:hover {
      background: var(--accent-dim);
      transform: translateY(-1px);
      box-shadow: var(--shadow-lg);
    }
    
    .btn-secondary {
      background: var(--bg-card);
      color: var(--text-primary);
      border: 1px solid var(--border-subtle);
      box-shadow: var(--shadow-sm);
    }
    
    .btn-secondary:hover {
      border-color: var(--border-active);
      box-shadow: var(--shadow-md);
    }
    
    .btn-outline {
      background: transparent;
      color: var(--text-secondary);
      border: 1px solid var(--border-subtle);
    }
    
    .btn-outline:hover {
      color: var(--text-primary);
      border-color: var(--text-primary);
      background: var(--bg-secondary);
    }
    
    .btn-warm {
      background: var(--warm);
      color: white;
    }
    
    .btn-warm:hover {
      filter: brightness(1.1);
      transform: translateY(-1px);
      box-shadow: 0 6px 20px rgba(220, 38, 38, 0.3);
    }
    
    .btn:disabled {
      cursor: not-allowed;
      opacity: 0.65;
      transform: none;
      box-shadow: none;
    }

    /* Hero */
    .hero {
      text-align: center;
      padding: 80px 0 60px;
    }
    
    @media (min-width: 768px) {
      .hero { padding: 100px 0 80px; }
    }
    
    .hero-title {
      margin-top: 0;
      font-size: 40px;
      font-weight: 700;
      line-height: 1.1;
      letter-spacing: -0.03em;
      color: var(--text-primary);
    }
    
    @media (min-width: 768px) {
      .hero-title { font-size: 56px; }
    }
    
    @media (min-width: 1024px) {
      .hero-title { font-size: 72px; }
    }
    
    .hero-subtitle {
      margin-top: 24px;
      font-size: 18px;
      color: var(--text-secondary);
      max-width: 900px;
      margin-left: auto;
      margin-right: auto;
      line-height: 1.7;
    }
    
    .hero-version {
      margin-top: 0;
      margin-bottom: 28px;
      font-family: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
      font-size: 13px;
      color: var(--text-muted);
      background: var(--bg-secondary);
      display: inline-block;
      padding: 6px 14px;
      border-radius: 20px;
      border: 1px solid var(--border-subtle);
    }
    
    .hero-cta {
      margin-top: 40px;
      display: flex;
      flex-direction: column;
      gap: 16px;
      justify-content: center;
      align-items: center;
    }
    
    @media (min-width: 640px) {
      .hero-cta { flex-direction: row; }
    }
    
    .hero-cta .btn {
      padding: 16px 32px;
      font-size: 16px;
      font-weight: 600;
      min-width: 200px;
    }

    /* 产品界面展示 */
    .hero-product {
      width: 100%;
      max-width: 1080px;
      margin: 56px auto 0;
      border: 1px solid var(--border-subtle);
      border-radius: 20px;
      background: var(--bg-card);
      box-shadow: var(--shadow-lg);
      overflow: hidden;
      position: relative;
    }

    .hero-product::after {
      content: "";
      position: absolute;
      inset: 0;
      pointer-events: none;
      background: linear-gradient(180deg, rgba(255,255,255,0.04), transparent 28%);
    }

    .hero-product-image {
      display: block;
      width: 100%;
      height: auto;
    }

    @media (max-width: 767px) {
      .hero-product {
        margin-top: 40px;
        border-radius: 14px;
      }
    }

    /* AI 场景 */
    .scenarios {
      padding: 100px 0 80px;
    }

    .scenario-heading {
      text-align: center;
      margin-bottom: 48px;
    }

    .scenario-label {
      display: block;
      color: var(--text-muted);
      font-size: 13px;
      font-weight: 600;
      letter-spacing: 0.04em;
    }

    .scenario-heading h2 {
      margin-top: 20px;
      color: var(--text-primary);
      font-size: 52px;
      font-weight: 700;
      line-height: 1.15;
      letter-spacing: -0.04em;
    }

    .scenario-intro {
      max-width: 900px;
      margin: 20px auto 0;
      color: var(--text-secondary);
      font-size: 16px;
      line-height: 1.7;
    }

    .scenario-tabs {
      display: grid;
      grid-template-columns: repeat(5, 1fr);
      width: fit-content;
      margin: 0 auto;
      padding: 5px;
      border-radius: 16px;
      background: var(--bg-secondary);
    }

    .scenario-tab {
      min-width: 92px;
      padding: 12px 22px;
      border: 1px solid transparent;
      border-radius: 12px;
      background: transparent;
      color: var(--text-secondary);
      font: 500 15px 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
      cursor: pointer;
      transition: color 0.2s, background 0.2s, border-color 0.2s;
    }

    .scenario-tab:hover {
      color: var(--text-primary);
    }

    .scenario-tab.active {
      border-color: var(--accent);
      background: var(--accent);
      color: #fff;
      box-shadow: var(--shadow-sm);
    }

    .scenario-showcase {
      display: grid;
      grid-template-columns: 38% 62%;
      min-height: 520px;
      margin-top: 48px;
      padding: 0;
      border: 1px solid var(--border-subtle);
      border-radius: 24px;
      background: var(--bg-card);
      box-shadow: var(--shadow-sm);
      overflow: hidden;
    }

    .scenario-copy {
      display: flex;
      flex-direction: column;
      justify-content: center;
      padding: 56px;
    }

    .scenario-number {
      color: var(--text-muted);
      font-family: 'JetBrains Mono', monospace;
      font-size: 13px;
      letter-spacing: 0.08em;
    }

    .scenario-copy h3 {
      margin-top: 28px;
      color: var(--text-primary);
      font-size: 30px;
      line-height: 1.3;
      font-weight: 500;
    }

    .scenario-headline {
      margin-top: 8px;
      color: var(--text-primary);
      font-size: 30px;
      line-height: 1.45;
      font-weight: 700;
    }

    .scenario-description {
      max-width: 330px;
      margin-top: 28px;
      color: var(--text-secondary);
      font-size: 15px;
      line-height: 1.85;
    }

    .scenario-visual {
      display: flex;
      align-items: flex-end;
      overflow: hidden;
      padding: 32px 0 0 52px;
      background: linear-gradient(135deg, #eef6ff 0%, #f4f0ff 100%);
    }

    .scenario-visual img {
      display: block;
      width: 112%;
      max-width: none;
      height: auto;
      border-radius: 16px 0 0;
    }

    @media (max-width: 767px) {
      .scenarios { padding: 72px 0 56px; }
      .scenario-heading { margin-bottom: 32px; }
      .scenario-heading h2 { margin-top: 16px; font-size: 38px; }
      .scenario-intro { font-size: 15px; }
      .scenario-tabs { width: 100%; margin: 0; grid-template-columns: repeat(5, minmax(0, 1fr)); }
      .scenario-tab { min-width: 0; padding: 11px 8px; }
      .scenario-showcase { grid-template-columns: 1fr; min-height: 0; }
      .scenario-copy { padding: 40px; }
      .scenario-visual { min-height: 320px; padding: 24px 0 0 24px; }
      .scenario-headline { font-size: 26px; }
    }
    
    /* Promo Banner */
    .promo {
      padding: 40px 0 100px;
    }
    
    .promo-card {
      position: relative;
      border-radius: 24px;
      overflow: hidden;
      background: linear-gradient(135deg, var(--warm-light) 0%, #fff 60%, var(--bg-secondary) 100%);
      border: 1px solid var(--border-subtle);
      box-shadow: var(--shadow-lg);
    }
    
    .promo-content {
      position: relative;
      padding: 40px 32px;
      display: flex;
      flex-direction: column;
      gap: 32px;
      align-items: center;
    }
    
    @media (min-width: 1024px) {
      .promo-content {
        flex-direction: row;
        padding: 48px 48px;
      }
    }
    
    .promo-text {
      flex: 1;
      text-align: center;
    }
    
    @media (min-width: 1024px) {
      .promo-text { text-align: left; }
    }
    
    .promo-badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      padding: 6px 18px;
      border-radius: 9999px;
      background: #FEF3C7;
      border: none;
      color: #B45309;
      font-size: 13px;
      font-weight: 600;
      letter-spacing: 0.06em;
      box-shadow: inset 0 0 0 1px rgba(180, 83, 9, 0.08);
    }
    
    .promo-title {
      margin-top: 16px;
      font-size: 26px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--text-primary);
    }
    
    @media (min-width: 768px) {
      .promo-title { font-size: 32px; }
    }
    
    .promo-desc {
      margin-top: 12px;
      color: var(--text-secondary);
      font-size: 15px;
      line-height: 1.7;
      max-width: 480px;
    }
    
    .promo-actions {
      margin-top: 24px;
      display: flex;
      flex-direction: column;
      gap: 12px;
      align-items: center;
    }
    
    @media (min-width: 640px) {
      .promo-actions {
        flex-direction: row;
      }
    }
    
    .promo-note {
      font-size: 13px;
      color: var(--text-muted);
    }
    
    .promo-stat {
      position: relative;
      flex-shrink: 0;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .promo-image {
      width: 180px;
      height: 180px;
      border-radius: 20px;
      object-fit: cover;
      box-shadow: none;
      border: none;
    }

    @media (min-width: 768px) {
      .promo-image {
        width: 200px;
        height: 200px;
      }
    }
    
    .promo-stat-card {
      width: 160px;
      height: 160px;
      border-radius: 20px;
      background: white;
      border: 2px solid var(--border-subtle);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      box-shadow: var(--shadow-md);
      position: relative;
    }
    
    @media (min-width: 768px) {
      .promo-stat-card {
        width: 180px;
        height: 180px;
      }
    }
    
    .promo-stat-label {
      font-size: 11px;
      color: var(--text-muted);
      letter-spacing: 0.1em;
      font-weight: 600;
      text-transform: uppercase;
    }
    
    .promo-stat-value {
      font-size: 36px;
      font-weight: 800;
      font-family: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
      color: var(--warm);
      margin: 4px 0;
    }
    
    @media (min-width: 768px) {
      .promo-stat-value { font-size: 44px; }
    }
    
    .promo-stat-unit {
      font-size: 13px;
      color: var(--text-secondary);
      font-weight: 500;
    }
    
    /* Stats Section */
    .stats {
      padding: 80px 0;
      border-top: 1px solid var(--border-subtle);
      border-bottom: 1px solid var(--border-subtle);
    }
    
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
    }
    
    @media (min-width: 768px) {
      .stats-grid { grid-template-columns: repeat(4, 1fr); }
    }
    
    .stat-item {
      text-align: center;
    }
    
    .stat-value {
      font-size: 36px;
      font-weight: 700;
      color: var(--text-primary);
      font-family: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    }
    
    @media (min-width: 768px) {
      .stat-value { font-size: 44px; }
    }
    
    .stat-label {
      font-size: 14px;
      color: var(--text-secondary);
      margin-top: 8px;
      font-weight: 500;
    }
    
    /* How It Works */
    .how-it-works {
      padding: 100px 0 80px;
    }
    
    .section-header {
      text-align: center;
      margin-bottom: 48px;
    }
    
    .section-label {
      font-size: 13px;
      font-weight: 600;
      color: var(--text-muted);
      letter-spacing: 0.1em;
      text-transform: uppercase;
    }
    
    .section-title {
      font-size: 32px;
      font-weight: 700;
      letter-spacing: -0.025em;
      color: var(--text-primary);
      margin-top: 12px;
    }
    
    @media (min-width: 768px) {
      .section-title { font-size: 40px; }
    }
    
    .section-subtitle {
      margin-top: 12px;
      color: var(--text-secondary);
      font-size: 16px;
      max-width: 500px;
      margin-left: auto;
      margin-right: auto;
      line-height: 1.6;
    }
    
    .steps-grid {
      display: grid;
      gap: 24px;
      grid-template-columns: 1fr;
    }
    
    @media (min-width: 768px) {
      .steps-grid { grid-template-columns: repeat(3, 1fr); }
    }
    
    .step-card {
      border-radius: 20px;
      border: 1px solid var(--border-subtle);
      background: var(--bg-card);
      padding: 32px;
      position: relative;
      transition: all 0.3s;
    }
    
    .step-card:hover {
      border-color: var(--border-active);
      box-shadow: var(--shadow-md);
    }
    
    .step-number {
      width: 48px;
      height: 48px;
      border-radius: 12px;
      background: var(--accent);
      color: white;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
      font-weight: 700;
      margin-bottom: 20px;
    }
    
    .step-title {
      font-size: 20px;
      font-weight: 700;
      color: var(--text-primary);
      margin-bottom: 8px;
    }
    
    .step-desc {
      font-size: 15px;
      color: var(--text-secondary);
      line-height: 1.6;
    }
    
    /* Download Section */
    .download {
      padding: 80px 0;
      background: var(--bg-secondary);
      margin: 0 -24px;
      padding-left: 24px;
      padding-right: 24px;
    }
    
    @media (min-width: 768px) {
      .download {
        margin: 0 -48px;
        padding-left: 48px;
        padding-right: 48px;
      }
    }
    
    .download-grid {
      display: grid;
      gap: 20px;
      grid-template-columns: 1fr;
    }
    
    @media (min-width: 768px) {
      .download-grid { grid-template-columns: repeat(3, 1fr); }
    }
    
    .download-card {
      position: relative;
      border-radius: 20px;
      border: 1px solid var(--border-subtle);
      background: var(--bg-card);
      padding: 32px;
      cursor: pointer;
      transition: all 0.3s;
      box-shadow: var(--shadow-sm);
    }
    
    .download-card:hover {
      border-color: var(--accent);
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
    }
    
    .download-card:hover .download-icon {
      background: var(--accent);
      color: white;
    }
    
    .download-icon {
      width: 56px;
      height: 56px;
      border-radius: 14px;
      background: var(--bg-secondary);
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--text-secondary);
      transition: all 0.3s;
    }
    
    .download-name {
      margin-top: 20px;
      font-size: 20px;
      font-weight: 700;
      color: var(--text-primary);
    }
    
    .download-arch {
      margin-top: 4px;
      color: var(--text-secondary);
      font-size: 14px;
      font-weight: 500;
    }
    
    .download-meta {
      margin-top: 16px;
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 13px;
      color: var(--text-muted);
      font-family: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    }
    
    .download-meta-dot {
      width: 4px;
      height: 4px;
      border-radius: 50%;
      background: var(--text-muted);
    }
    
    .download-btn {
      margin-top: 24px;
      width: 100%;
      padding: 14px;
      border-radius: 12px;
      background: var(--bg-secondary);
      border: 1px solid var(--border-subtle);
      color: var(--text-primary);
      font-size: 15px;
      font-weight: 600;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      cursor: pointer;
      transition: all 0.2s;
    }
    
    .download-card:hover .download-btn {
      background: var(--accent);
      color: white;
      border-color: var(--accent);
    }
    
    .download-requirements {
      margin-top: 32px;
      text-align: center;
      font-size: 13px;
      color: var(--text-muted);
    }
    
    /* Features */
    .features {
      padding: 80px 0;
    }
    
    .features-grid {
      display: grid;
      gap: 20px;
      grid-template-columns: 1fr;
    }
    
    @media (min-width: 640px) {
      .features-grid { grid-template-columns: repeat(2, 1fr); }
    }
    
    .feature-card {
      border-radius: 20px;
      border: 1px solid var(--border-subtle);
      background: var(--bg-card);
      padding: 32px;
      transition: all 0.3s;
      box-shadow: var(--shadow-sm);
    }
    
    .feature-card:hover {
      border-color: var(--border-active);
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
    }
    
    .feature-icon {
      width: 48px;
      height: 48px;
      border-radius: 12px;
      background: var(--bg-secondary);
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent);
    }
    
    .feature-title {
      margin-top: 16px;
      font-size: 18px;
      font-weight: 700;
      color: var(--text-primary);
    }
    
    .feature-desc {
      margin-top: 8px;
      color: var(--text-secondary);
      font-size: 15px;
      line-height: 1.6;
    }
    
    /* Testimonials */
    .testimonials {
      padding: 80px 0;
      background: var(--bg-secondary);
      margin: 0 -24px;
      padding-left: 24px;
      padding-right: 24px;
    }
    
    @media (min-width: 768px) {
      .testimonials {
        margin: 0 -48px;
        padding-left: 48px;
        padding-right: 48px;
      }
    }
    
    .testimonials-grid {
      display: grid;
      gap: 20px;
      grid-template-columns: 1fr;
    }
    
    @media (min-width: 768px) {
      .testimonials-grid { grid-template-columns: repeat(3, 1fr); }
    }
    
    .testimonial-card {
      border-radius: 20px;
      border: 1px solid var(--border-subtle);
      background: var(--bg-card);
      padding: 28px;
      box-shadow: var(--shadow-sm);
    }
    
    .testimonial-text {
      font-size: 15px;
      color: var(--text-secondary);
      line-height: 1.7;
      font-style: italic;
    }
    
    .testimonial-author {
      margin-top: 20px;
      display: flex;
      align-items: center;
      gap: 12px;
    }
    
    .testimonial-avatar {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: var(--bg-secondary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      color: var(--text-primary);
      font-size: 14px;
    }
    
    .testimonial-info {
      flex: 1;
    }
    
    .testimonial-name {
      font-size: 14px;
      font-weight: 600;
      color: var(--text-primary);
    }
    
    .testimonial-role {
      font-size: 13px;
      color: var(--text-muted);
    }
    
    /* CTA Section */
    .cta {
      padding: 100px 0;
      text-align: center;
    }
    
    .cta-title {
      font-size: 36px;
      font-weight: 700;
      color: var(--text-primary);
      letter-spacing: -0.025em;
    }
    
    @media (min-width: 768px) {
      .cta-title { font-size: 48px; }
    }
    
    .cta-subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-top: 16px;
      max-width: 500px;
      margin-left: auto;
      margin-right: auto;
      line-height: 1.6;
    }
    
    .cta-btn {
      margin-top: 32px;
      padding: 18px 40px;
      font-size: 16px;
    }
    
    #invite-form input:focus {
      border-color: var(--border-active) !important;
    }

    .modal-overlay {
      display: none;
      position: fixed;
      inset: 0;
      z-index: 9999;
      background: rgba(0, 0, 0, 0.4);
      backdrop-filter: blur(4px);
      -webkit-backdrop-filter: blur(4px);
      align-items: center;
      justify-content: center;
    }

    .modal-card {
      background: var(--bg-card);
      border-radius: 24px;
      border: 1px solid var(--border-subtle);
      box-shadow: var(--shadow-xl);
      max-width: 440px;
      width: 90%;
      padding: 40px 32px;
      position: relative;
    }

    .modal-close {
      position: absolute;
      top: 16px;
      right: 16px;
      background: none;
      border: none;
      cursor: pointer;
      color: var(--text-muted);
      font-size: 24px;
      line-height: 1;
    }

    .modal-title {
      font-size: 24px;
      font-weight: 700;
      color: var(--text-primary);
      margin-bottom: 8px;
    }

    .modal-desc {
      font-size: 14px;
      color: var(--text-secondary);
      line-height: 1.7;
      margin-bottom: 28px;
    }

    .modal-field {
      margin-bottom: 16px;
    }

    .modal-field-last {
      margin-bottom: 24px;
    }

    .modal-field label {
      display: block;
      font-size: 13px;
      font-weight: 600;
      color: var(--text-secondary);
      margin-bottom: 6px;
    }

    .modal-field input {
      width: 100%;
      padding: 12px 14px;
      border-radius: 10px;
      border: 1px solid var(--border-subtle);
      background: var(--bg-secondary);
      font-size: 14px;
      color: var(--text-primary);
      outline: none;
      font-family: inherit;
      transition: border-color 0.2s;
    }

    .modal-submit {
      width: 100%;
      padding: 14px;
      font-size: 15px;
      border-radius: 12px;
    }

    .modal-result {
      text-align: center;
      padding: 20px 0;
    }

    .modal-result-icon {
      width: 64px;
      height: 64px;
      border-radius: 50%;
      background: var(--warm-light);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
    }

    .modal-result-title {
      font-size: 22px;
      font-weight: 700;
      color: var(--text-primary);
      margin-bottom: 8px;
    }

    .modal-result-desc {
      font-size: 14px;
      color: var(--text-secondary);
      line-height: 1.7;
    }

    .modal-result-action {
      margin-top: 24px;
      padding: 12px 32px;
    }