svg.css

// final svg thing done!! 
<style> 
@keyframes draw {
  0% { stroke-dashoffset: 1000; stroke-width: 5; }
  100% { stroke-dashoffset: 0; stroke-width: 5; }
}

@keyframes gradualFill {
  0% { stop-color: transparent; stroke-width: 5; }
  100% { stop-color: black; stroke-width: 0; }
}

@keyframes remove {
  0% { opacity: 1; }
  100% { opacity: 0; }
}

path {
  fill: url(#gradualFillGradient); /* Reference the gradient for the fill */
  stroke: black;
  stroke-width: 5; /* Initial stroke width for drawing */
  stroke-dasharray: 1000;
  stroke-dashoffset: 1000;
  animation: 
    draw 4s linear forwards,              /* Stroke drawing over 4 seconds */
    gradualFill 4s ease-in-out 4s forwards, /* Gradual fill starts after 4 seconds */
    remove 2s ease-in 8s forwards;        /* Fade out starts at 8 seconds */
}

/* Define the gradient for gradual filling */
linearGradient {
  stop {
    stop-color: transparent;
    animation: gradualFill 4s ease-in-out 4s forwards; /* Gradual fill starts after 4s */
  }
}
</style>

<svg width="400" height="400" xmlns="http://www.w3.org/2000/svg">
  <!-- Gradient Definition -->
  <defs>
    <linearGradient id="gradualFillGradient" x1="0%" y1="0%" x2="0%" y2="100%">
      <stop offset="0%" stop-color="transparent">
        <animate attributeName="stop-color" from="transparent" to="black" dur="4s" begin="4s" fill="freeze" />
      </stop>
      <stop offset="100%" stop-color="black" />
    </linearGradient>
  </defs>
</svg>