body {
    font-family: Arial, sans-serif;
    background: linear-gradient(135deg, #0f172a, #1e293b);
    color: white;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
  }
  h1 {
    color: #22d3ee;
  }
  .container {
    background: rgba(255, 255, 255, 0.1);
    padding: 20px;
    border-radius: 12px;
    width: 100%;
    max-width: 400px;
  }
  input {
    width: 70%;
    padding: 10px;
    border-radius: 8px;
    border: none;
    margin-right: 10px;
  }
  button {
    padding: 10px 14px;
    border: none;
    border-radius: 8px;
    background: #22d3ee;
    color: #0f172a;
    cursor: pointer;
  }
  ul {
    list-style: none;
    padding: 0;
    margin-top: 20px;
  }
  li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255, 255, 255, 0.1);
    padding: 10px;
    margin-bottom: 8px;
    border-radius: 8px;
  }
  li.done {
    text-decoration: line-through;
    color: #94a3b8;
  }