body {
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #FFFFFF;
    font-family: Arial, sans-serif;
    transition: background-color 1s ease;
  }
  
  .container {
    text-align: center;
  }
  
  h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
  }
  
  p {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
  }
  
  button {
    font-size: 1.2rem;
    padding: 10px 20px;
    background-color: #333;
    color: #fff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
    margin-top: 10px;
  }
  
  button:hover {
    background-color: #555;
  }
  
  .color-info {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: 20px;
  }
  
  #color-code, #rgb-code {
    font-size: 1.5rem;
    font-weight: bold;
    margin-top: 10px;
  }
  
  .copy-btn, .fav-btn {
    margin-top: 10px;
    padding: 5px 10px;
    font-size: 1rem;
  }
  
  h2 {
    font-size: 1.8rem;
    margin-top: 30px;
  }
  
  .color-history, .favorite-colors, .complementary-color {
    display: flex;
    gap: 10px;
    margin-top: 20px;
  }
  
  .color-history-item, .favorite-color-item, .complementary-color {
    width: 40px;
    height: 40px;
    cursor: pointer;
    border-radius: 5px;
    border: 2px solid #333;
  }