Shine / Shimmer Effect

A light shimmer sweeps across the button on hover. Subtle and premium-feeling. Works well on solid-color or gradient buttons.

.btn-shine {
  padding: 12px 24px;
  background: #8b5cf6;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
}
.btn-shine::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left 0.5s;
}
.btn-shine:hover::before { left: 100%; }