.active{color:gold}.header{align-items:center;background-color:#000;border-bottom:1px solid #333;display:flex;justify-content:space-between;padding:20px}.logo{animation:flicker 1.5s infinite alternate;color:gold;cursor:pointer;font-weight:700}@keyframes flicker{0%{opacity:1}to{opacity:.85;text-shadow:0 0 10px gold,0 0 20px #fa0}}