body {
  position: relative;
}

main {
  padding: 20px;
  margin-top: 20px;
  background-color: #aaaaaa99;
}

footer {
  margin-top: 20px;
}

summary {
  cursor: pointer;
}

.center {
  text-align: center;
}

.heart {
  color: red;
}

.bg {
  opacity: 0.5;
  position: absolute;
  top: 0;
  left: 0;
  z-index: -1;
  height: 100vh;
  width: 100vw;
  background-image: url('https://storage.lolicon.in/img/93760908_p0.jpg');
  background-position: center top;
  background-repeat: no-repeat;
  background-size: cover;
  background-origin: padding-box;
  background-clip: padding-box;
  object-fit: cover;
}