Run Button

<!-- Run Button — toggle .is-running while the task is in progress -->
<button class="nuda-run" type="button">
  <span class="nuda-run__icon">
    <svg class="nuda-run__play" viewBox="0 0 24 24" fill="currentColor">
      <path d="M8 5 L19 12 L8 19 Z" />
    </svg>
    <span class="nuda-run__spinner"></span>
  </span>
  <span class="nuda-run__label">Run</span>
</button>

/* Run Button
   Play icon swaps for a spinner while .is-running.
   Customize: --run-bg, --run-fg */

.nuda-run {
  --run-bg: #e4ff54;
  --run-fg: #09090b;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 14px 7px 9px;
  background: var(--run-bg);
  border: none;
  border-radius: 7px;
  color: var(--run-fg);
  font: 700 0.875rem ui-sans-serif, system-ui, sans-serif;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.25s;
}

.nuda-run:hover {
  transform: translateY(-1px);
  box-shadow: 0 0 16px rgba(228, 255, 84, 0.4);
}

.nuda-run__icon {
  position: relative;
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(9, 9, 11, 0.15);
  border-radius: 5px;
  flex-shrink: 0;
}

.nuda-run__play {
  width: 11px;
  height: 11px;
  margin-left: 1px;
  transition: opacity 0.2s, transform 0.2s;
}

.nuda-run__spinner {
  position: absolute;
  width: 14px;
  height: 14px;
  border: 1.5px solid rgba(9, 9, 11, 0.2);
  border-top-color: var(--run-fg);
  border-radius: 50%;
  opacity: 0;
  animation: nuda-run-spin 1s linear infinite;
}

.nuda-run.is-running .nuda-run__play    { opacity: 0; transform: scale(0.4); }
.nuda-run.is-running .nuda-run__spinner { opacity: 1; }

@keyframes nuda-run-spin { to { transform: rotate(360deg); } }

@media (prefers-reduced-motion: reduce) {
  .nuda-run__spinner { animation: none; }
}