.aside{height:200px;max-height:0;opacity:0;transition:all .3s linear}.aside-open{max-height:200px;opacity:1}header.slide-down{animation:headerDown .3s linear forwards;position:fixed;top:0;z-index:99999}@keyframes headerDown{0%{opacity:0;transform:translateY(-200px)}to{opacity:1;transform:translateY(0)}}