body {
    margin: 0;
    font-family: 'Open Sans', sans-serif;
    background: linear-gradient(to bottom, #e0f0ff, #ffffff);
    color: #003366;
  }

  header {
    text-align: center;
    padding: 2rem 1rem;
    background: #007BFF;
    color: white;
    font-family: 'Mountains of Christmas', cursive;
    font-size: 2.5rem;
    letter-spacing: 1px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
  }

  .countdown {
    text-align: center;
    padding: 1.5rem;
    font-size: 1.5rem;
  }

  #timer {
    font-size: 2rem;
    font-weight: bold;
    color: #0056b3;
    margin-top: 0.5rem;
  }

  .card {
    margin: 1.5rem auto;
    max-width: 800px;
    background: white;
    border-radius: 15px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.05);
    overflow: hidden;
    border: 2px solid #cce6ff;
  }

  .card-header {
    cursor: pointer;
    background: #e6f0ff;
    padding: 1rem 1.2rem;
    font-size: 1.2rem;
    font-weight: bold;
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: background 0.3s;
  }

  .card-header:hover {
    background: #d9ecff;
  }

  .card-content {
    max-height: 0;
    overflow: hidden;
    padding: 0 1.2rem;
    background: #f9fcff;
    transition: max-height 0.4s ease, padding 0.4s ease;
  }

  .card-content.open {
    padding: 1.2rem;
  }

  .card-content.open p, 
  .card-content.open ul, 
  .card-content.open h3, 
  .card-content.open h4 {
    margin-top: 0;
  }

  .rotate {
    transform: rotate(90deg);
    transition: transform 0.3s ease;
  }

  .card-header.open .rotate {
    transform: rotate(270deg);
  }

  footer {
    text-align: center;
    padding: 1rem;
    font-size: 0.9rem;
    color: #666;
  }

  @media (max-width: 600px) {
    header { font-size: 2rem; }
    #timer { font-size: 1.5rem; }
    .card-header { font-size: 1rem; }
  }

  /* For better readability of long sections */
  .card-content h3, .card-content h4 {
    margin-top: 1rem;
    color: #004080;
  }

  .card-content ul {
    margin: 0.5rem 0 1rem 1.5rem;
  }

  .card-content strong {
    color: #003366;
  }