* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
      min-height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 20px;
    }

    .container {
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      border-radius: 20px;
      padding: 40px;
      box-shadow: 0 25px 50px rgba(0, 0, 0, 0.2);
      width: 100%;
      max-width: 600px;
      animation: fadeIn 0.6s ease-out;
    }

    @keyframes fadeIn {
      from {
        opacity: 0;
        transform: translateY(30px);
      }
      to {
        opacity: 1;
        transform: translateY(0);
      }
    }

    h1 {
      text-align: center;
      color: #333;
      margin-bottom: 30px;
      font-size: 2.5rem;
      background: linear-gradient(135deg, #667eea, #764ba2);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .input-container {
      display: flex;
      gap: 15px;
      margin-bottom: 30px;
      flex-wrap: wrap;
    }

    #url-input {
      flex: 1;
      padding: 15px 20px;
      border: 2px solid #e0e0e0;
      border-radius: 12px;
      font-size: 16px;
      outline: none;
      transition: all 0.3s ease;
      min-width: 300px;
    }

    #url-input:focus {
      border-color: #667eea;
      box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
    }

    #shorten-btn {
      background: linear-gradient(135deg, #667eea, #764ba2);
      color: white;
      border: none;
      padding: 15px 30px;
      border-radius: 12px;
      font-size: 16px;
      font-weight: 600;
      cursor: pointer;
      transition: all 0.3s ease;
      white-space: nowrap;
    }

    #shorten-btn:hover {
      transform: translateY(-2px);
      box-shadow: 0 10px 25px rgba(102, 126, 234, 0.3);
    }

    #shorten-btn:active {
      transform: translateY(0);
    }

    #shorten-btn:disabled {
      opacity: 0.6;
      cursor: not-allowed;
      transform: none;
    }

    h2 {
      color: #333;
      margin-bottom: 20px;
      font-size: 1.5rem;
      border-bottom: 2px solid #f0f0f0;
      padding-bottom: 10px;
    }

    #url-list {
      list-style: none;
      max-height: 400px;
      overflow-y: auto;
    }

    #url-list::-webkit-scrollbar {
      width: 6px;
    }

    #url-list::-webkit-scrollbar-track {
      background: #f1f1f1;
      border-radius: 3px;
    }

    #url-list::-webkit-scrollbar-thumb {
      background: #c1c1c1;
      border-radius: 3px;
    }

    .url-item {
      background: #f8f9ff;
      border: 1px solid #e6e9ff;
      border-radius: 12px;
      padding: 20px;
      margin-bottom: 15px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      transition: all 0.3s ease;
      animation: slideIn 0.4s ease-out;
    }

    @keyframes slideIn {
      from {
        opacity: 0;
        transform: translateX(-20px);
      }
      to {
        opacity: 1;
        transform: translateX(0);
      }
    }

    .url-item:hover {
      transform: translateY(-2px);
      box-shadow: 0 8px 25px rgba(102, 126, 234, 0.15);
    }

    .url-content {
      flex: 1;
      min-width: 0;
    }

    .short-url {
      color: #667eea;
      text-decoration: none;
      font-weight: 600;
      font-size: 16px;
      display: block;
      margin-bottom: 5px;
      word-break: break-all;
    }

    .short-url:hover {
      text-decoration: underline;
    }

    .original-url {
      color: #666;
      font-size: 14px;
      word-break: break-all;
      opacity: 0.8;
    }

    .copy-btn {
      background: #4CAF50;
      color: white;
      border: none;
      padding: 10px 20px;
      border-radius: 8px;
      cursor: pointer;
      font-size: 14px;
      font-weight: 500;
      transition: all 0.3s ease;
      margin-left: 15px;
    }

    .copy-btn:hover {
      background: #45a049;
      transform: scale(1.05);
    }

    .empty-state {
      text-align: center;
      color: #666;
      font-style: italic;
      padding: 40px 20px;
      background: #f9f9f9;
      border-radius: 12px;
      border: 2px dashed #ddd;
    }

    .loading {
      text-align: center;
      color: #667eea;
      padding: 20px;
      font-size: 16px;
    }

    .error {
      background: #ffebee;
      color: #c62828;
      padding: 15px;
      border-radius: 8px;
      margin-bottom: 20px;
      border-left: 4px solid #c62828;
    }

    @media (max-width: 600px) {
      .container {
        padding: 20px;
        margin: 10px;
      }

      .input-container {
        flex-direction: column;
      }

      #url-input {
        min-width: auto;
      }

      .url-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 15px;
      }

      .copy-btn {
        margin-left: 0;
        align-self: stretch;
      }

      h1 {
        font-size: 2rem;
      }
    }