<button class="btn-ice">
  <span class="btn-ice-frost" aria-hidden="true"></span>
  <span class="btn-ice-glint" aria-hidden="true"></span>
  <span class="btn-ice-text">Cool Down</span>
</button>

.btn-ice {
  position: relative;
  padding: 14px 30px;
  border: 1px solid rgba(168,224,240,0.5);
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(168,224,240,0.55), rgba(93,158,176,0.65));
  color: #0a3a4a;
  font-family: ui-sans-serif, system-ui;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  cursor: pointer;
  overflow: hidden;
  -webkit-backdrop-filter: blur(8px) saturate(140%);
  backdrop-filter: blur(8px) saturate(140%);
  box-shadow: 0 8px 22px -8px rgba(15,80,100,0.4), inset 0 1px 0 rgba(255,255,255,0.6);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}
.btn-ice-frost {
  position: absolute; inset: 0;
  background:
    radial-gradient(ellipse at 30% 20%, rgba(255,255,255,0.55), transparent 60%),
    repeating-linear-gradient(45deg, rgba(255,255,255,0.04) 0 2px, transparent 2px 4px);
  pointer-events: none;
}
.btn-ice-glint {
  position: absolute; top: -50%; left: -30%;
  width: 30%; height: 200%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.7), transparent);
  transform: rotate(20deg);
  transition: left 0.5s cubic-bezier(.3,1,.3,1);
  pointer-events: none;
}
.btn-ice-text { position: relative; z-index: 1; }
.btn-ice:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 28px -8px rgba(15,80,100,0.5), inset 0 1px 0 rgba(255,255,255,0.7);
}
.btn-ice:hover .btn-ice-glint { left: 130%; }