:root {
  --border-radius: 12px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;

  --foreground-rgb: 255, 255, 255;
  --background-rgb: 10, 10, 10;
  --shadow-rgb: 20, 20, 20;
  --callout-rgb: 238, 240, 241;
  --callout-border-rgb: 172, 175, 176;
  --card-rgb: 180, 185, 188;
  --card-border-rgb: 131, 134, 135;
}

* {
  margin: 0;
  padding: 0;
}

body {
  color: rgb(var(--foreground-rgb));
  background: rgb(var(--background-rgb));
}

main {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.centre {
  margin: 40vh 0;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.centre #begin {
  background-color: rgb(var(--card-rgb));
  border: 1px solid rgb(var(--card-border-rgb));
  border-radius: var(--border-radius);
  padding: 1rem 1.2rem;
  transition: background 200ms, border 200ms;
  width: 75%;
}

.centre #beginOff {
  visibility: none;
  opacity: 0;
  transition: visibility 0.5s, opacity 0.5s linear;
  background: rgb(var(--card-rgb));
  border: 1px solid rgb(var(--card-border-rgb));
  border-radius: var(--border-radius);
  padding: 1rem 1.2rem;
  width: 75%;
}

.headphonesOff {
  visibility: visible;
  opacity: 0;
  transition: display 2s, opacity 2s linear;
  display: inherit;
  flex-direction: inherit;
  align-items: center;
}

.headphonesOn {
  visibility: visible;
  opacity: 1;
  transition: opacity 2s linear;
  display: inherit;
  flex-direction: inherit;
  align-items: center;
}

#headphonesImage {
  height: 100px;
  width: 100px;
  margin-bottom: 10px;
}

footer {
  position: fixed;
  width: 100%;
  bottom: 5dvh;
  display: flex;
  justify-content: space-evenly;
  align-items: center;
}

footer section {
  justify-self: center;
}

#credits {
  text-align: right;
}

#creditsOff {
  visibility: none;
  opacity: 0;
  transition: visibility 0.3s, opacity 0.3s linear;
}

.controlButtonOff {
  visibility: none;
  opacity: 0;
}

.controlButtonOn {
  visibility: visible;
  opacity: 1;
  transition: opacity 2s linear;
  border-radius: var(--border-radius);
  background: none;
  border: none;
  cursor: pointer;
  height: 60px;
  width: 60px;
  justify-content: center;
  align-items: center;
}

.controlButtonOn:hover {
  background-color: rgb(var(--shadow-rgb));
}

.controlImage {
  height: 40px;
  width: 40px;
}

.arrowButton {
  background-color: rgb(var(--background-rgb));
  border: 1px solid rgb(var(--background-rgb));
  border-radius: var(--border-radius);
  padding: 1rem 1.2rem;
  cursor: pointer;
}

.arrowButton:hover {
  border: 1px solid rgb(var(--shadow-rgb));
  background-color: rgb(var(--shadow-rgb));
}

.arrowImage {
  width: 75px;
}

.navigationOff {
  display: none;
}

.navigationOn {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  justify-content: center;
  width: 30dvw;
  position: fixed;
  bottom: 12.5dvh;
}

/* Enable hover only on non-touch devices */
@media (hover: hover) and (pointer: fine) {
  .centre #button:hover {
    background: rgba(var(--card-rgb), 0.7);
    border: 1px solid rgba(var(--card-border-rgb), 0.7);
  }
}

@media (prefers-reduced-motion) {
  .centre #button:hover {
    transform: none;
  }
}