styles.css

body {
    font-family: Roboto;
    background: #0F2027;  /* fallback for old browsers */
    background: -webkit-linear-gradient(to right, #2C5364, #203A43, #0F2027);  /* Chrome 10-25, Safari 5.1-6 */
    background: linear-gradient(to right, #2C5364, #203A43, #0F2027); /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */
}

h1 {
    background: #2980b9;
    color: white;
    margin: 0;
    padding: 10px 20px;
    text-transform: uppercase;
    font-size: 24px;
    font-weight: normal;
}

ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

li {
    background: #fff;
    height: 40px;
    line-height: 40px;
    color: #666;
}

/* style every other <li> */
li:nth-child(2n) {
    background: #f7f7f7;
}

li:hover span {
    width: 40px;
    opacity: 1.0;
}

.fa-arrow-down, .fa-arrow-up {
    float: right;
}

span {
    background: #e74c3c;
    height: 40px;
    margin-right: 20px;
    text-align: center;
    color: white;
    width: 0;
    display: inline-block;
    transition: 0.2s linear;
    opacity: 0;
}

span:nth-child(2) {
    background: #298383;
}

.completed {
    color: gray;
    text-decoration: line-through;
}



/* The Modal (background) */
.modal {
    display: none; /* Hidden by default */
    position: fixed; /* Stay in place */
    z-index: 1; /* Sit on top */
    padding-top: 100px; /* Location of the box */
    left: 0;
    top: 0;
    width: 100%; /* Full width */
    height: 100%; /* Full height */
    overflow: auto; /* Enable scroll if needed */
    background-color: rgb(0,0,0); /* Fallback color */
    background-color: rgba(0,0,0,0.4); /* Black w/ opacity */
  }
  
  /* Modal Content */
  .modal-content {
    background-color: #fefefe;
    margin: auto;
    padding: 20px;
    border: 1px solid #888;
    width: 40%;
  }

  .modal-content span {
      opacity: 1;
  }

  .modal-content p {
    display: flex;
    flex-direction: column;
  }

  .modal-content p input {
    margin-bottom: 5px;
  }
  
  .modal-heading {
      background-color: #888;
      margin: 0;
      color: white;
      padding: 1.5em;
  }
  
  /* The Close Button */
  .close {
    color: white;
    float: right;
    font-size: 28px;
    font-weight: bold;
  }
  
  .close:hover,
  .close:focus {
    color: #000;
    text-decoration: none;
    cursor: pointer;
  }