html{scroll-behavior:smooth}.btn{background-color:#9333ea;color:#fff;padding:10px 20px;border:none;border-radius:8px;cursor:pointer}.btn:hover{background-color:#7e22ce}.section{opacity:0;transform:translateY(40px);transition:opacity .8s ease,transform .8s ease}.section.visible{opacity:1;transform:translateY(0)}