<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 80">
  <!-- Long-lived entity holding state (a card) -->
  <rect x="24" y="20" width="52" height="40" rx="4" fill="none" stroke="#888" stroke-width="2"/>
  <line x1="24" y1="30" x2="76" y2="30" stroke="#888" stroke-width="1.5"/>

  <!-- Current state marker -->
  <circle cx="35" cy="42" r="4" fill="#cc2222"/>
  <text x="45" y="45" font-family="sans-serif" font-size="9" fill="#888">state</text>

  <!-- Persisted / mutating over time -->
  <rect x="45" y="51" width="6" height="6" rx="1" fill="none" stroke="#cc2222" stroke-width="1.5"/>
</svg>
