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

html {
  height: 100%;
}

body {
  min-height: 100%;
  background: #000;
}

.toggle-input {
  display: none;
}

.background-label {
  position: fixed;
  display: block;
  top: 0;
  left: 0;
  opacity: 0;
  transition: opacity 0.15s ease-in;
}

.bg {
  display: block;
  width: 100vw;
  height: 100vh;
  object-fit: contain;
}

#toggle-bg1:checked ~ label[for=toggle-bg2] {
  opacity: 1;
  z-index: 9999;
}

#toggle-bg2:checked ~ label[for=toggle-bg3] {
  opacity: 1;
  z-index: 9999;
}

#toggle-bg3:checked ~ label[for=toggle-bg1] {
  opacity: 1;
  z-index: 9999;
}