html, body {
      height: 100%;
      width: 100%;
      margin: 0;
      padding: 0;
      overflow: hidden;
    }
    body {
      height: 100vh;
      width: 100vw;
      position: relative;
      font-family: monospace;
      background: #111;
      margin: 0;
      padding: 0;
    }
    #ascii-bg {
      position: fixed;
      top: 0; left: 0;
      width: 100vw;
      height: 100vh;
      color: #666;
      font-size: 12px;
      line-height: 12px;
      white-space: pre;
      z-index: 0;
      pointer-events: none;
      user-select: none;
      margin: 0;
      padding: 0;
    }
    .center-content {
      position: fixed;
      top: 0; left: 0;
      width: 100vw;
      height: 100vh;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      z-index: 1;
      text-align: center;
      margin: 0;
      padding: 0;
    }
    .codex-title {
      font-size: 2.5rem;
      color: #fff;
      margin-bottom: 2rem;
      letter-spacing: 2px;
      text-shadow: 0 0 8px #222;
        font-weight: bold;
        box-shadow: 0 0 12px #2224;
    }
    .signin-btn {
      padding: 1rem 2rem;
      font-size: 1.1rem;
      border-radius: 2rem;
      border: none;
      background: #fff;
      color: #222;
      cursor: pointer;
      box-shadow: 0 2px 8px #2224;
      transition: background 0.2s;
      text-decoration: none;
    }
    .signin-btn:hover {
      background: #000000;
      color: #fff;
      box-shadow: #fff 0 0 12px;
    }