.achievement-logo {
  position: relative;
  border: 0;
  padding: 0;
  cursor: pointer;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}
/* Enlarge the cap's touch target without changing the header layout. */
header .achievement-logo::before { content: ''; position: absolute; inset: -6px; }
.achievement-logo:active { filter: brightness(1.15); }
.achievement-burst {
  position: fixed;
  z-index: 9999;
  width: 0;
  height: 0;
  pointer-events: none;
}
.achievement-burst span {
  position: absolute;
  left: -7px;
  top: -10px;
  color: #e6aa22;
  font: 20px/1 sans-serif;
  text-shadow: 0 0 6px #fff2b5, 0 1px 2px #765009;
  animation: achievement-sparkle 700ms ease-out both;
}
.achievement-burst span:nth-child(even) { color: #fff0a3; font-size: 15px; }
@keyframes achievement-sparkle {
  0% { opacity: 0; transform: scale(.3); }
  18% { opacity: 1; }
  65% { opacity: 1; }
  100% { opacity: 0; transform: translate(var(--x), var(--y)) rotate(var(--turn)) scale(.45); }
}
@media (prefers-reduced-motion: reduce) {
  .achievement-burst span { animation: none; transform: translate(var(--x), var(--y)); }
}
@media print { .achievement-burst { display: none; } }