body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
  }
  
  .container {
    margin: 50px auto;
    padding: 20px;
    background-color: #fff;
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
  }
  
  h1 {
    text-align: center;
  }
  
  form {
    margin-bottom: 20px;
  }
  
  input[type="text"] {
    padding: 8px;
    font-size: 16px;
  }

  #task-input{
    text-align: center;
  }

  #task-form{
    text-align: center;
  }
  
  button {
    padding: 8px 20px;
    font-size: 16px;
    background-color: green;
    color: #fff;
    border: none;
    border-radius: 3px;
    cursor: pointer;
    text-align: center;
  }
  
  button:hover {
    background-color: red;
  }
  
  ul {
    list-style-type: none;
    padding: 0;
  }
  
  li {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px;
    border-bottom: 1px solid #ddd;
  }
  
  .completed {
    text-decoration: line-through;
    color: black;
  }