/* 画面全体を縦方向のflexboxに */
html, body {
    height: 100%;
    margin: 0;
    font-family: sans-serif;
    background: #f7f7f7;
  }
  
  .wrapper {
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between; /* 上下にパーツを分ける */
    padding: 1em;
    box-sizing: border-box;
  }
  
  .main {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    justify-content: center; /* 中央寄せ */
    align-items: center;
    text-align: center;
  }
  
  #passphrase {
    font-size: 1.5em;
    margin-bottom: 0.5em;
    cursor: pointer;
    user-select: all;
  }
  
  #toast {
    font-size: 0.9em;
    color: green;
    margin-bottom: 1em;
  }
  
  .hidden {
    display: none;
  }
  
  /* オプションは画面下部に配置される */
  .options {
    padding: 1em;
    background: #f0f0f0;
    border-top: 1px solid #ccc;
    display: flex;
    flex-direction: column;
    gap: 0.5em;
  }
  
  /* PC の時は横並びにする */
  @media screen and (min-width: 768px) {
    .options {
      flex-direction: row;
      justify-content: center;
      align-items: center;
    }
  }