<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
  <defs>
    <linearGradient id="sphereGradient" x1="0%" y1="0%" x2="100%" y2="100%">
      <stop offset="0%" stop-color="#3B82F6" />
      <stop offset="50%" stop-color="#06B6D4" />
      <stop offset="100%" stop-color="#2DD4BF" />
    </linearGradient>
  </defs>
  
  <!-- Background circle -->
  <circle cx="50" cy="50" r="48" fill="#0f172a"/>
  
  <!-- Outer ring -->
  <circle cx="50" cy="50" r="45" fill="none" stroke="url(#sphereGradient)" stroke-width="3" opacity="0.4"/>
  
  <!-- Inner ring -->
  <circle cx="50" cy="50" r="38" fill="none" stroke="url(#sphereGradient)" stroke-width="2" opacity="0.6"/>
  
  <!-- Main S letter -->
  <text x="50" y="68" text-anchor="middle" font-size="55" font-weight="bold" font-family="Arial, sans-serif" fill="url(#sphereGradient)">S</text>
  
  <!-- Decorative nodes -->
  <circle cx="20" cy="30" r="4" fill="#3B82F6"/>
  <circle cx="80" cy="30" r="3" fill="#06B6D4"/>
  <circle cx="15" cy="60" r="3" fill="#2DD4BF"/>
  <circle cx="85" cy="65" r="4" fill="#3B82F6"/>
</svg>
