body{background:#f8f9fa}.todo-card{max-width:600px;width:100%;transition:.3s}.todo-item{transition:all .3s ease}.todo-item:hover{background:#f1f1f1;transform:scale(1.01)}.completed span{text-decoration:line-through;color:gray}.fade-in{animation:fadeIn .4s ease-in-out}@keyframes fadeIn{0%{opacity:0;transform:translateY(-5px)}to{opacity:1;transform:translateY(0)}}