:root {
  --warpstrike-gold-metal:linear-gradient(90deg,
    #6c5522 0%,#bd9750 7%,#fffcc6 14%,#f1d48a 21%,
    #fdfbc5 28.5%,#fee490 36%,#fffcc6 43%,#a98749 50%,
    #fffcc6 57%,#fee490 64%,#fdfbc5 71.5%,#f1d48a 79%,
    #fffcc6 86%,#bd9750 93%,#6c5522 100%);
}

@keyframes warpstrike-gold-flow {
  from { background-position:0% 50%; }
  to { background-position:200% 50%; }
}
@keyframes warpstrike-gold-pulse {
  0%,100% { filter:drop-shadow(0 0 3px rgba(255,205,65,.58)); }
  50% { filter:drop-shadow(0 0 8px rgba(255,220,105,1)); }
}

/* Keep the detailed medal artwork, but colour its opaque Gold pixels with the
   supplied reflected metallic gradient. Silver and Bronze remain untouched. */
.active-medal[data-tier="gold"],
.medal-choice[data-tier-select="gold"] .medal-art,
.solo-tier-medal.gold {
  position:relative;
  isolation:isolate;
  background-image:none !important;
}
.active-medal[data-tier="gold"]::before,
.medal-choice[data-tier-select="gold"] .medal-art::before,
.solo-tier-medal.gold::before,
.active-medal[data-tier="gold"]::after,
.medal-choice[data-tier-select="gold"] .medal-art::after,
.solo-tier-medal.gold::after {
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  border-radius:50%;
}
.active-medal[data-tier="gold"]::before,
.medal-choice[data-tier-select="gold"] .medal-art::before,
.solo-tier-medal.gold::before {
  background:var(--warpstrike-gold-metal);
  background-size:200% 100%;
  -webkit-mask-image:url('../medals/tier-medals-v1.png');
  -webkit-mask-position:left center;
  -webkit-mask-size:300% auto;
  -webkit-mask-repeat:no-repeat;
  mask-image:url('../medals/tier-medals-v1.png');
  mask-position:left center;
  mask-size:300% auto;
  mask-repeat:no-repeat;
  animation:warpstrike-gold-flow 3s linear infinite,warpstrike-gold-pulse 1.8s ease-in-out infinite;
}
.active-medal[data-tier="gold"]::after,
.medal-choice[data-tier-select="gold"] .medal-art::after,
.solo-tier-medal.gold::after {
  background:url('../medals/tier-medals-v1.png') left center / 300% auto no-repeat;
  filter:grayscale(1) contrast(1.15);
  mix-blend-mode:multiply;
  opacity:.52;
}

/* Challenge keeps the engraved medal texture and sends a reflected highlight
   across its face. The level number remains readable over the star. */
.challenge-level-medal.gold { isolation:isolate; animation:warpstrike-gold-pulse 1.8s ease-in-out infinite; }
.challenge-level-medal.gold::after {
  position:absolute;
  z-index:1;
  inset:1%;
  border-radius:50%;
  background:linear-gradient(110deg,transparent 25%,rgba(255,255,214,.82) 42%,transparent 57%);
  background-size:220% 100%;
  mix-blend-mode:screen;
  content:"";
  animation:warpstrike-gold-flow 3s linear infinite;
}
.challenge-level-medal.gold .challenge-medal-number { z-index:2; }

@media (prefers-reduced-motion:reduce) {
  .active-medal[data-tier="gold"]::before,
  .medal-choice[data-tier-select="gold"] .medal-art::before,
  .solo-tier-medal.gold::before,
  .challenge-level-medal.gold,
  .challenge-level-medal.gold::after { animation:none; background-position:50% 50%; }
}