.flash-button{position:relative}.flash-button:before{content:"";position:absolute;top:0;left:0;width:100%;height:100%;border-radius:inherit;background-color:#2563eb;opacity:0;transition:opacity .3s;pointer-events:none}.flash-button.animate-flash-15s:before{animation:flash-pseudo 15s infinite}@keyframes flash-pseudo{0%,90%,to{opacity:0}95%{opacity:1}}