body {
      font-family: 'Segoe UI', sans-serif;
      background: #f0f4f8;
      margin: 0;
      padding: 0;
      display: flex;
      flex-direction: column;
      min-height: 100vh;
    }
    header {
      background: #1e88e5;
      color: white;
      padding: 20px;
      text-align: center;
      font-size: 24px;
    }
    .container {
      padding: 20px;
      max-width: 800px;
      margin: auto;
      flex: 1;
    }
    .card-list {
      display: flex;
      flex-wrap: wrap;
      gap: 20px;
    }
    .card {
      background: #fff;
      border-radius: 12px;
      box-shadow: 0 4px 8px rgba(0,0,0,0.1);
      padding: 20px;
      width: 260px;
      position: relative;
      transition: transform 0.2s;
    }
    .card:hover {
      transform: scale(1.03);
    }
    .card p {
      margin: 8px 0;
    }
    .card-icons {
      position: absolute;
      bottom: 10px;
      right: 10px;
      display: flex;
      gap: 10px;
    }
    .card-icons i {
      cursor: pointer;
      color: #666;
      transition: color 0.2s;
    }
    .card-icons i:hover {
      color: #1e88e5;
    }
    button {
      background: #1e88e5;
      color: white;
      border: none;
      padding: 12px 20px;
      border-radius: 8px;
      cursor: pointer;
      margin-top: 20px;
      font-weight: bold;
      transition: background 0.3s;
    }
    button:hover {
      background: #1565c0;
    }
    .add-form {
      margin-top: 30px;
      background: #ffffff;
      padding: 30px;
      border-radius: 16px;
      box-shadow: 0 8px 20px rgba(0,0,0,0.1);
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .add-form h3 {
      text-align: center;
      margin-bottom: 16px;
      color: #1e88e5;
    }
    .add-form input, .add-form select {
      padding: 12px;
      border: 2px solid #ccc;
      border-radius: 8px;
      font-size: 16px;
      transition: border 0.2s;
    }
    .add-form input:focus, .add-form select:focus {
      outline: none;
      border-color: #1e88e5;
    }
    .modal {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(0, 0, 0, 0.5);
      justify-content: center;
      align-items: center;
      z-index: 1000;
    }
    .modal-content {
      background: white;
      padding: 30px;
      border-radius: 12px;
      width: 320px;
      box-shadow: 0 5px 15px rgba(0,0,0,0.3);
      text-align: left;
      position: relative;
    }
    .modal-content h3 {
      margin-top: 0;
      text-align: center;
    }
    .modal-content p {
      margin: 10px 0;
    }
    .copy-btn {
      color: #1e88e5;
      cursor: pointer;
      margin-left: 8px;
      font-size: 14px;
      transition: color 0.2s;
    }
    .copy-btn:hover {
      color: #0d47a1;
    }
    .close-btn {
      background: #e53935;
      color: white;
      border: none;
      padding: 10px 20px;
      margin-top: 20px;
      border-radius: 8px;
      cursor: pointer;
      display: block;
      margin-left: auto;
      margin-right: auto;
    }
    .error-msg {
      color: red;
      margin-top: 10px;
      display: none;
    }

    footer {
      background-color: #1e88e5;
      color: white;
      padding: 16px 20px;
      font-size: 14px;
      border-top: 2px solid #1565c0;
    }
    .footer-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      max-width: 1000px;
      margin: auto;
    }
    .footer-content p {
      margin: 0;
      text-align: center;
      flex: 1;
    }
    .footer-icons {
      display: flex;
      gap: 15px;
    }
    .footer-icons a {
      color: white;
      font-size: 18px;
      transition: color 0.3s;
    }
    .footer-icons a:hover {
      color: #bbdefb;
    }

    @media (max-width: 768px) {
      header {
        font-size: 20px;
        padding: 16px;
      }
      .container {
        padding: 10px;
      }
      .card {
        width: 100%;
        padding: 16px;
      }
      .add-form {
        padding: 20px;
      }
      button {
        padding: 10px 16px;
      }
      .add-form input, .add-form select {
        font-size: 14px;
      }
    }
    @media (max-width: 480px) {
      .modal-content {
        padding: 20px;
      }
      .add-form h3 {
        font-size: 18px;
      }
      .card-icons {
        position: static;
        justify-content: end;
        margin-top: 10px;
      }
    }