:root {
      --primary: rgb(255,59,48);
      --primary-hover: rgb(230,45,35);
      --accent-blue: #1D7BFF;
      --text-main: #1E293B;
      --text-muted: #64748B;
      --text-light: #F8FAFC;
      --bg-white: #FFFFFF;
      --bg-light: #F8FAFC;
      --border-color: #E2E8F0;
      --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
      --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    }

    * { box-sizing: border-box; margin: 0; padding: 0; }
    body { font-family: var(--font-family); color: var(--text-main); background: var(--bg-white); line-height: 1.6; }
    a { color: inherit; text-decoration: none; transition: all 0.3s; }

    .container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 20px; }
    .section-padding { padding: 80px 0; }

    
    .header { position: sticky; top: 0; z-index: 100; background: rgba(255, 255, 255, 0.9); backdrop-filter: blur(10px); border-bottom: 1px solid var(--border-color); }
    .header-nav { display: flex; align-items: center; justify-content: space-between; height: 72px; }
    .logo { display: inline-flex; align-items: center; gap: 12px; }
    .logo img { height: 40px; }
    .logo span { font-size: 18px; font-weight: 800; }
    .nav-menu { display: flex; gap: 24px; }
    .nav-menu a { font-size: 15px; font-weight: 500; color: var(--text-muted); }
    .nav-menu a:hover { color: var(--primary); }
    .header-actions { display: flex; gap: 16px; align-items: center; }
    .btn { display: inline-flex; padding: 10px 20px; border-radius: 8px; font-size: 14px; font-weight: 600; cursor: pointer; border: none; align-items:center; justify-content:center; }
    .btn-primary { background: var(--primary); color: #fff; }
    .btn-outline { background: transparent; border: 1.5px solid var(--border-color); }
    .menu-toggle { display: none; background: none; border: none; }
    .menu-toggle span { display: block; width: 24px; height: 2px; background: var(--text-main); margin: 5px 0; }

    
    .drawer-backdrop { position: fixed; top: 0; left: 0; width: 100vw; height: 100vh; background: rgba(0,0,0,0.5); z-index: 199; opacity: 0; pointer-events: none; }
    .drawer { position: fixed; top: 0; left: -280px; width: 280px; height: 100vh; background: #fff; z-index: 200; display: flex; flex-direction: column; padding: 24px; transition: left 0.3s; }
    .drawer.active { left: 0; }
    .drawer-backdrop.active { opacity: 1; pointer-events: auto; }
    .drawer-header { display: flex; justify-content: space-between; margin-bottom: 32px; }
    .drawer-close { background: none; border: none; font-size: 24px; }
    .drawer-menu { display: flex; flex-direction: column; gap: 16px; }

    
    .download-hero { background: linear-gradient(135deg, #111827 0%, #030712 100%); color: var(--text-light); padding: 80px 0; text-align: center; border-bottom: 1px solid rgba(255,255,255,0.1); }
    .download-badge { display: inline-block; padding: 6px 14px; background: rgba(239, 68, 68, 0.15); border: 1px solid rgba(239, 68, 68, 0.3); color: #FCA5A5; border-radius: 99px; font-size: 13px; font-weight: 600; margin-bottom: 20px; }
    .download-hero h1 { font-size: 42px; font-weight: 800; margin-bottom: 20px; }
    .download-hero p { font-size: 18px; color: #94A3B8; max-width: 650px; margin: 0 auto; }

    
    .portal-section { background: var(--bg-light); }
    .portal-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
    .portal-card { background: var(--bg-white); border: 1px solid var(--border-color); border-radius: 16px; padding: 40px 30px; text-align: center; display: flex; flex-direction: column; align-items: center; transition: all 0.3s; }
    .portal-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); border-color: var(--primary); }
    .portal-icon { font-size: 48px; margin-bottom: 24px; }
    .portal-card h3 { font-size: 22px; font-weight: 700; margin-bottom: 12px; }
    .portal-card p { color: var(--text-muted); font-size: 14px; margin-bottom: 30px; }
    .portal-card .btn { width: 100%; padding: 12px 20px; }
    
    
    .sim-qr-box { width: 140px; height: 140px; background: #F1F5F9; border: 4px solid var(--border-color); border-radius: 12px; display: flex; align-items: center; justify-content: center; position: relative; margin-bottom: 20px; }
    .sim-qr-box::before { content: '扫码极速获取'; font-size: 12px; font-weight: 600; color: var(--text-muted); }

    
    .steps-section { background: var(--bg-white); }
    .step-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin-top: 50px; }
    .step-card { position: relative; }
    .step-num { width: 40px; height: 40px; background: var(--primary); color: #fff; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: 800; font-size: 18px; margin-bottom: 16px; }
    .step-card h4 { font-size: 16px; font-weight: 700; margin-bottom: 8px; }
    .step-card p { font-size: 14px; color: var(--text-muted); }

    
    .footer { background: #0F172A; color: #94A3B8; padding: 80px 0 30px 0; border-top: 1px solid rgba(255,255,255,0.1); }
    .footer-grid { display: grid; grid-template-columns: 2fr repeat(3, 1fr); gap: 40px; margin-bottom: 60px; }
    .footer-info .logo { margin-bottom: 20px; }
    .footer-info .logo span { color: var(--text-light); }
    .footer-desc { font-size: 14px; line-height: 1.6; margin-bottom: 20px; }
    .footer-title { font-size: 16px; font-weight: 700; color: var(--text-light); margin-bottom: 24px; }
    .footer-links { display: flex; flex-direction: column; gap: 12px; }
    .footer-links a { font-size: 14px; }
    .footer-links a:hover { color: var(--primary); }
    .footer-contact { font-size: 14px; display: flex; flex-direction: column; gap: 12px; }
    .footer-contact-item { display: flex; align-items: center; gap: 8px; }
    .footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 30px; display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 20px; }
    .copyright { font-size: 13px; }

    @media (max-width: 991px) {
      .nav-menu, .header-actions .btn-outline { display: none; }
      .menu-toggle { display: block; }
      .portal-grid { grid-template-columns: 1fr; }
      .step-grid { grid-template-columns: repeat(2, 1fr); }
      .footer-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .step-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .footer-bottom { flex-direction: column; text-align: center; }
    }