.rsvp-section{background:radial-gradient(circle at center,#fff,#fdfbf7)}.btn-shimmer{position:relative;overflow:hidden;background:#1a1a1a;transition:all .5s cubic-bezier(.23,1,.32,1)}.btn-shimmer:before{content:"";position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:conic-gradient(from 0deg,transparent,rgba(180,140,80,.3),transparent 30%);animation:rotateShimmer 4s linear infinite}@keyframes rotateShimmer{to{transform:rotate(360deg)}}.rsvp-card{background:#fff9;-webkit-backdrop-filter:blur(15px);backdrop-filter:blur(15px);border:1px solid rgba(255,255,255,.4);box-shadow:0 20px 50px #0000000d}.letter-span{display:inline-block;will-change:transform,opacity}