*{margin:0;padding:0}h1{text-align:center;margin-top:25px}form{width:1170px;margin:auto;display:flex;gap:20px}form input{flex-basis:80%;height:40px}form button{flex-basis:20%}.outerdiv{width:1170px;margin:auto}.outerdiv ul{list-style:none;margin-top:40px}.outerdiv ul li{color:#fff;padding:10px;font-size:25px;margin-bottom:20px;position:relative;text-align:left;background-color:#000}.outerdiv ul li span{right:20px;position:absolute;cursor:pointer}.completetodo{text-decoration:line-through;color:red!important;background-color:#e8e85f!important}