html, body {
    height: 100%;
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
  }
  
  body {
    text-align: center;
    background: linear-gradient(to top, #505285 0%, #585e92 12%, #65689f 25%, #7474b0 37%, #7e7ebb 50%, #8389c7 62%, #9795d4 75%, #a2a1dc 87%, #b5aee4 100%);
  }
  
  #todo-container {
    padding: 20px;
    width: 400px;
    background: #f0f0f0;
    border: 1px solid #c1bdbd;
    box-shadow: rgba(0, 0, 0, 0.5) 0px 10px 30px;
    transform: translateY(-150px);
    border-radius: 22px;
  }
  
  #input-box, #due-date, #input-button {
    margin: 5px 0;
    padding: 5px;
  }
  
  #input-button {
    background: linear-gradient(to top, #505285 0%, #585e92 12%, #65689f 25%, #7474b0 37%, #7e7ebb 50%, #8389c7 62%, #9795d4 75%, #a2a1dc 87%, #b5aee4 100%);
    color: white;
    border: none;
    border-radius: 5px;
    padding: 10px;
    cursor: pointer;
  }
  
  ul {
    list-style: none;
    padding: 0;
  }
  
  li {
    background: #ddd;
    margin: 5px 0;
    padding: 5px;
    display: flex;
    justify-content: space-between;
    border-radius: 10px;
  }
  
  li.completed {
    text-decoration: line-through;
    color: #888;
  }