.kokuchi {
  width: 100%;
  max-width: 1024px;
  margin: 100px auto 2em;
  font-size: 16px;
}

@media screen and (max-width: 480px) {
  .kokuchi {
    margin: 100px auto 2em;
  }
}

.kokuchi h3 {
  font-size: 20px;
}

.kokuchi .gray_box {
  margin: 0 20px;
  padding: 1em;
  border: solid 1px #ccc;
}

.kokuchi .gray_box .win_box {
  display: none;
  margin: 1em;
  padding: 1em;
  background-color: #f0f0f0;
  font-size: 18px;
}