<form class="csb-aurora" role="search">
  <label class="csb-sr" for="csb-aurora-i">Search</label>
  <input id="csb-aurora-i" type="search" name="q" placeholder="Search premium..." />
</form>

.csb-aurora {
  position: relative; display: inline-block;
  padding: 4px;
  border-radius: 14px;
  background: #15151d;
  overflow: hidden;
  isolation: isolate;
}
.csb-aurora::before {
  content: ''; position: absolute;
  top: -40%; left: -20%;
  width: 140%; height: 220%;
  background:
    radial-gradient(ellipse 240px 120px at 20% 50%, rgba(124,108,255,0.55), transparent 60%),
    radial-gradient(ellipse 200px 100px at 60% 50%, rgba(255,108,138,0.45), transparent 60%),
    radial-gradient(ellipse 220px 120px at 100% 50%, rgba(46,204,138,0.35), transparent 60%);
  filter: blur(18px);
  z-index: -1;
  animation: csb-aurora-drift 14s ease-in-out infinite;
  opacity: 0.85;
}
.csb-aurora input {
  display: block;
  width: 240px; padding: 12px 16px;
  border: 1px solid rgba(255,255,255,0.06);
  outline: none;
  background: rgba(21,21,29,0.85);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  border-radius: 10px;
  color: #f0eeff; font: 500 14px/1 system-ui, sans-serif;
  transition: border-color 0.25s;
}
.csb-aurora:focus-within input { border-color: rgba(167,139,250,0.5); }
.csb-aurora input::placeholder { color: #b8b6d4; }
@keyframes csb-aurora-drift {
  0%, 100% { transform: translateX(0)    translateY(0); }
  50%       { transform: translateX(-8%) translateY(2%); }
}

.csb-sr {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (prefers-reduced-motion: reduce) {
  .csb-aurora,
  .csb-aurora * {
    animation: none !important;
  }
}