/* ── Active tool button — glowing ring using the button's own accent color ── */
.tool-btn.tool-active {
  background: color-mix(in srgb, var(--tool-color, #8b5cf6) 18%, transparent);
  box-shadow:
    0 0 0 2px var(--tool-color, #8b5cf6),
    0 4px 14px color-mix(in srgb, var(--tool-color, #8b5cf6) 25%, transparent);
  transform: scale(1.08);
}
@keyframes tool-btn-pulse {
  0%   { box-shadow: 0 0 0 0   color-mix(in srgb, var(--tool-color, #8b5cf6) 70%, transparent); }
  60%  { box-shadow: 0 0 0 10px transparent; }
  100% { box-shadow: 0 0 0 0   transparent; }
}
.tool-btn.tool-active {
  animation: tool-btn-pulse 0.45s ease-out;
}