header{background-color:#f0f8ff;text-align:center}body{margin:0;padding:0;background-color:azure;font-family:Arial,Helvetica,sans-serif}main{padding:.2em;min-height:600px}footer,h4{text-align:center}footer{background-color:#f0f8ff}.todo-container{max-width:400px;margin:50px auto;padding:20px;border:1px solid #ddd;border-radius:8px;background-color:#fff;box-shadow:0 2px 4px rgba(0,0,0,.1)}.todo-container button{margin-left:10px}.todo-container h4{text-align:center;margin-bottom:20px;color:#333}.input-section{display:flex;gap:10px;margin-bottom:20px}.input-section input{flex:1 1;padding:8px;border:1px solid #ccc;border-radius:4px;font-size:14px}.input-section button{padding:8px 12px;border:none;background-color:#28a745;color:#fff;border-radius:4px;font-size:14px;cursor:pointer;transition:background-color .3s}.input-section button:hover{background-color:#218838}.task-list{list-style:none;padding:0;margin:0}.task-item{display:flex;align-items:center;gap:10px;padding:8px 0;border-bottom:1px solid #eee}.task-item input[type=checkbox]{transform:scale(1.2);cursor:pointer}.task-item span{flex:1 1;font-size:14px;color:#555}.task-item span.completed{text-decoration:line-through;color:#999}.delete-button{background:none;border:none;color:#dc3545;font-size:16px;cursor:pointer;transition:color .3s}.delete-button:hover{color:#c82333}