:root {
      --primary: rgb(244,63,94);
      --primary-hover: rgb(225, 29, 72);
      --glacier-blue: #1D7BFF;
      --silver-white: #e6edf3;
      --deep-sea-ink: #0B0F19;
      --text-dark: #1f2937;
      --text-light: #6b7280;
      --bg-light: #f9fafb;
      --border-color: #e5e7eb;
      --card-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    }

    * { box-sizing: border-box; margin: 0; padding: 0; }
    body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; color: var(--text-dark); background: #fff; line-height: 1.6; }
    a { text-decoration: none; color: inherit; transition: all 0.3s; }

    
    .header { background: #fff; border-bottom: 1px solid var(--border-color); position: sticky; top: 0; z-index: 1000; height: 70px; display: flex; align-items: center; }
    .header-container { max-width: 1200px; margin: 0 auto; width: 100%; padding: 0 20px; display: flex; justify-content: space-between; align-items: center; }
    
    .logo { display: inline-flex; align-items: center; gap: 12px; text-decoration: none; }
    .logo img { display: block; height: 40px; width: auto; max-width: 160px; object-fit: contain; flex-shrink: 0; }
    .logo span { display: inline-block; font-size: 20px; font-weight: 800; line-height: 1; color: var(--text-dark); white-space: nowrap; }

    .nav-desktop { display: flex; align-items: center; gap: 24px; }
    .nav-desktop a { font-size: 15px; font-weight: 500; color: #4b5563; padding: 6px 0; border-bottom: 2px solid transparent; }
    .nav-desktop a:hover { color: var(--primary); border-bottom-color: var(--primary); }

    .menu-toggle { display: none; background: none; border: none; font-size: 24px; cursor: pointer; color: var(--text-dark); }

    
    .drawer-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.5); z-index: 2000; opacity: 0; visibility: hidden; transition: all 0.3s; }
    .drawer-overlay.active { opacity: 1; visibility: visible; }
    .nav-drawer { position: fixed; top: 0; left: -280px; width: 280px; height: 100%; background: #fff; z-index: 2100; transition: all 0.3s ease-in-out; padding: 30px 20px; display: flex; flex-direction: column; gap: 30px; }
    .nav-drawer.active { left: 0; }
    .drawer-header { display: flex; justify-content: space-between; align-items: center; border-bottom: 1px solid var(--border-color); padding-bottom: 15px; }
    .drawer-close { background: none; border: none; font-size: 24px; cursor: pointer; color: var(--text-dark); }
    .drawer-menu { display: flex; flex-direction: column; gap: 20px; }
    .drawer-menu a { font-size: 16px; font-weight: 600; color: #374151; }
    .drawer-menu a:hover { color: var(--primary); }

    
    .page-banner { background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%); color: #fff; padding: 50px 20px; text-align: center; }
    .page-banner h1 { font-size: 32px; font-weight: 800; margin-bottom: 10px; }
    .page-banner p { color: #94a3b8; font-size: 15px; }

    
    .download-layout { max-width: 1100px; margin: 60px auto; padding: 0 20px; display: grid; grid-template-columns: 1.2fr 1fr; gap: 50px; align-items: center; }
    
    .download-options { display: flex; flex-direction: column; gap: 24px; }
    .download-card { background: var(--bg-light); border: 1px solid var(--border-color); border-radius: 12px; padding: 24px; display: flex; align-items: center; gap: 20px; transition: all 0.3s; }
    .download-card:hover { border-color: var(--primary); transform: translateX(5px); }
    .dl-icon { font-size: 36px; background: #fff; border: 1px solid var(--border-color); width: 60px; height: 60px; border-radius: 12px; display: flex; align-items: center; justify-content: center; color: var(--primary); }
    .dl-info { flex-grow: 1; }
    .dl-info h3 { font-size: 18px; font-weight: 700; margin-bottom: 4px; }
    .dl-info p { font-size: 13px; color: var(--text-light); }
    .btn-download-app { background: var(--primary); color: #fff; padding: 10px 20px; border-radius: 6px; font-size: 13px; font-weight: 600; text-align: center; }
    .btn-download-app:hover { background: var(--primary-hover); }

    
    .qr-visual-block { text-align: center; background: #fff; border: 1px solid var(--border-color); border-radius: 20px; padding: 40px; box-shadow: var(--card-shadow); }
    .mock-qr-code { width: 180px; height: 180px; background: #f3f4f6; border: 2px solid var(--primary); border-radius: 16px; margin: 0 auto 20px auto; display: flex; flex-direction: column; align-items: center; justify-content: center; position: relative; }
    .mock-qr-code::before { content: '扫码安装'; font-size: 14px; font-weight: 600; color: var(--primary); }
    .mock-qr-code::after { content: 'iOS / Android'; font-size: 11px; color: var(--text-light); margin-top: 5px; }
    .qr-visual-block h2 { font-size: 24px; font-weight: 800; margin-bottom: 12px; }
    .qr-visual-block p { font-size: 14px; color: var(--text-light); }

    
    .steps-section { background: var(--bg-light); padding: 60px 20px; border-top: 1px solid var(--border-color); border-bottom: 1px solid var(--border-color); }
    .steps-container { max-width: 1000px; margin: 0 auto; }
    .steps-title { text-align: center; font-size: 24px; font-weight: 800; margin-bottom: 40px; }
    .steps-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
    .step-card { text-align: center; background: #fff; border: 1px solid var(--border-color); border-radius: 12px; padding: 30px; }
    .step-num { width: 40px; height: 40px; background: var(--primary); color: #fff; font-size: 18px; font-weight: 700; border-radius: 50%; display: inline-flex; align-items: center; justify-content: center; margin-bottom: 15px; }
    .step-card h4 { font-size: 16px; font-weight: 700; margin-bottom: 10px; }
    .step-card p { font-size: 13px; color: var(--text-light); }

    
    .footer { background: #111827; color: #9ca3af; padding: 60px 0 30px 0; font-size: 14px; border-top: 4px solid var(--primary); }
    .footer-container { max-width: 1200px; margin: 0 auto; padding: 0 20px; display: grid; grid-template-columns: 2fr repeat(3, 1fr); gap: 40px; margin-bottom: 40px; }
    
    .footer-logo-col { display: flex; flex-direction: column; gap: 20px; }
    .footer-logo-col .logo span { color: #fff; }
    .footer-desc { line-height: 1.6; }
    
    .footer-title { color: #fff; font-size: 16px; font-weight: 700; margin-bottom: 20px; }
    .footer-links { list-style: none; display: flex; flex-direction: column; gap: 12px; }
    .footer-links a:hover { color: #fff; }
    
    .footer-bottom { max-width: 1200px; margin: 0 auto; padding: 30px 20px 0 20px; border-top: 1px solid #1f2937; display: flex; justify-content: space-between; align-items: center; }
    .footer-bottom-links { display: flex; gap: 20px; }

    
    @media (max-width: 992px) {
      .download-layout { grid-template-columns: 1fr; }
      .steps-grid { grid-template-columns: 1fr; }
      .footer-container { grid-template-columns: 1fr; gap: 30px; }
      .nav-desktop { display: none; }
      .menu-toggle { display: block; }
    }