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

img {
  width: 100%;
}

@media screen and (min-width: 1404px) {
  .pc-only {
    display: block;
  }

  .sp-only {
    display: none;
  }

  html {
      font-size: 0.83vw;
  }

  .future-letter-container {
      position: relative;
  }

  .future-letter-iframe {
      position: absolute;
      width: 65.625rem;
      /* height: 114.6875rem; */
      height: 200rem;
      top: 21.4rem;
      left: 0;
      right: 0;
      margin: 0 auto;
      border: none;
  }
}

@media screen and (max-width: 1404px) {
  .pc-only {
    display: none;
  }

  .sp-only {
    display: block;
  }

  html {
    font-size: 2.13vw;
  }

  .future-letter-container {
      position: relative;
  }

  .future-letter-iframe {
      position: absolute;
      width: 37rem;
      /* height: 117rem; */
      height: 200rem;
      /* height: 1400rem; */
      top: 22.5rem;
      left: -0.4rem;
      right: 0;
      margin: 0 auto;
      border: none;
  }  
}