    /* CSSスタイル */
    body {
      background-color: #1c1c1c;
      color: #fff;
      font-family: Arial, sans-serif;
    }

    .container {
      max-width: 400px;
      margin: 0 auto;
      padding: 20px;
    }

    .form-group {
      margin-bottom: 20px;
    }

    input[type="text"],
    input[type="email"] {
      width: 100%;
      padding: 8px;
      border: none;
      border-radius: 4px;
      background-color: #333;
      color: #fff;
    }

    input[type="submit"] {
      padding: 10px 20px;
      border: none;
      border-radius: 4px;
      background-color: #7289da;
      color: #fff;
      cursor: pointer;
    }

    .error-box {
      display: none;
      position: fixed;
      top: 20px;
      left: 50%;
      transform: translateX(-50%);
      max-width: 400px;
      padding: 10px;
      background-color: #ff0000;
      color: #fff;
      text-align: center;
      animation: errorAnimation 2s ease-in-out;
    }

    .loader-container {
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      background-color: #000;
      z-index: 9999;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .loader {
      width: 50px;
      height: 50px;
      border: 3px solid #fff;
      border-radius: 50%;
      border-top-color: transparent;
      animation: spin 1s linear infinite;
    }

    /* 追加のCSSスタイル */
    .embed {
      border: 1px solid #7289da;
      border-radius: 4px;
      background-color: #36393f;
      padding: 10px;
      margin-top: 20px;
    }

    .embed-title {
      color: #fff;
      font-weight: bold;
    }

    .embed-field {
      color: #b9bbbe;
      margin-top: 10px;
    }

    .embed-field-name {
      font-weight: bold;
      margin-right: 5px;
    }

    .embed-field-value {
      margin-left: 5px;
    }

    @keyframes errorAnimation {
      0% {
        opacity: 0;
      }
      10% {
        opacity: 1;
      }
      90% {
        opacity: 1;
      }
      100% {
        opacity: 0;
      }
    }

    @keyframes spin {
      0% {
        transform: rotate(0deg);
      }
      100% {
        transform: rotate(360deg);
      }
    }