<style>
    body {
      margin: 0;
      padding: 0;
      display: flex;
      justify-content: center;
      align-items: center;
      min-height: 100vh;
      background-color: #0033a0; /* 深藍色背景 */
      font-family: "微軟正黑體", Arial, sans-serif;
    }
    
    .signup-button {
      position: relative;
      padding: 15px 40px;
      font-size: 20px;
      font-weight: bold;
      color: #ffffff;
      background-color: transparent;
      border: 2px solid #00ffcc;
      border-radius: 4px;
      cursor: pointer;
      overflow: hidden;
      box-shadow: 0 0 15px rgba(0, 255, 204, 0.5);
      transition: all 0.3s ease;
      animation: float 2s ease-in-out infinite;
      letter-spacing: 2px;
      text-shadow: 0 0 5px rgba(0, 255, 204, 0.7);
    }
    
    .signup-button:hover {
      background-color: rgba(0, 255, 204, 0.2);
      box-shadow: 0 0 20px rgba(0, 255, 204, 0.8);
      transform: translateY(-2px);
    }
    
    .signup-button:active {
      transform: translateY(1px);
    }
    
    @keyframes float {
      0% {
        transform: translateY(0px);
      }
      50% {
        transform: translateY(-10px);
      }
      100% {
        transform: translateY(0px);
      }
    }
    
    /* 添加網絡背景效果 */
    .background {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: 
        radial-gradient(circle at 10% 20%, rgba(0, 255, 204, 0.1) 1px, transparent 1px),
        radial-gradient(circle at 50% 70%, rgba(0, 255, 204, 0.1) 1px, transparent 1px),
        radial-gradient(circle at 90% 40%, rgba(0, 255, 204, 0.1) 1px, transparent 1px);
      background-size: 50px 50px;
      z-index: -1;
    }
  </style>