Holographic Card

<div class="holographic-card">
  <div class="holographic-content">
    <h3 style="margin: 0 0 8px 0; font-size: 18px;">Holographic</h3>
    <p style="margin: 0; color: #666;">Rainbow border effect</p>
  </div>
</div>

.holographic-card {
  width: 300px;
  height: 200px;
  border-radius: 16px;
  background: linear-gradient(45deg, #ff00ff, #00ffff, #ffff00, #ff00ff);
  background-size: 400% 400%;
  animation: holographic-shift 3s ease infinite;
  position: relative;
  overflow: hidden;
  cursor: pointer;
  transition: transform 0.3s ease;
}
.holographic-card:hover {
  transform: scale(1.05);
}
.holographic-card::before {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  right: 2px;
  bottom: 2px;
  background: #fff;
  border-radius: 14px;
  z-index: 1;
}
.holographic-content {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  z-index: 2;
  color: #333;
  text-align: center;
  padding: 20px;
}
@keyframes holographic-shift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}