body:not(:has(main)) {
  background-color: black;
  color: white;
}

.nightmare {
  font-size: 60pt;
  font-family: Garamond, serif;
  color: silver;
  text-shadow: 4px 0 4px gray;
  filter: shadow(color=gray, direction=90);
}

.nightmare2 {
  font-size: 60pt;
  font-family: Garamond, serif;
  color: #777777;
  text-shadow: 0 -4px 4px #333333;
  filter: shadow(color=#333333, direction=360);
}

ul.chapter {
  font-size: 24px;
  font-weight: bold;
  list-style: none;
  padding: 0;
}

.page {
  font-size: 48px;
  font-family:
    ＭＳ 明朝,
    serif;
}

.space {
  margin-top: 48px;
  margin-bottom: 48px;
}

table.ending {
  font-size: 24px;
}

pre#story {
  font-size: 16px;
  margin-top: 48px;
  margin-bottom: 64px;
}

div#bgm {
  margin-top: 16px;
  margin-bottom: 16px;
}

div#bgmplay {
  margin-top: 16px;
  margin-bottom: 16px;
}