body{margin:0;padding:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Open Sans,Helvetica Neue,sans-serif;background-color:#f5f5f5}.container{max-width:600px;padding:20px;background-color:#fff;border-radius:8px;box-shadow:0 2px 10px rgba(0,0,0,.1);margin:50px auto 0}.header{text-align:center;margin-bottom:30px}.input-container{display:flex;gap:10px;margin-bottom:20px}.todo-input{flex:1 1;padding:10px;border:1px solid #ddd;border-radius:4px;font-size:16px}.add-button{padding:10px 20px;background-color:#0070f3;color:#fff;border:none;border-radius:4px;cursor:pointer;font-size:16px}.add-button:hover{background-color:#0060e0}.todo-list{list-style-type:none;padding:0}.todo-item{display:flex;align-items:center;padding:15px;border-bottom:1px solid #eee}.todo-item:last-child{border-bottom:none}.todo-checkbox{margin-right:15px;width:18px;height:18px;cursor:pointer}.todo-text{flex:1 1;font-size:16px}.todo-text.completed{text-decoration:line-through;color:#888}.delete-button{background-color:red;color:#fff;border:none;border-radius:4px;padding:5px 10px;cursor:pointer;font-size:14px}.delete-button:hover{background-color:#c00}