style.css

* {
  box-sizing: border-box;
}

:root {
  --background: pink;
  --button: #aa9999;
  --button-split: #99888f;
  --active: #ff8833;
}

html {
  height: 100%;
  width: 100%;
}

body {
  font-family: "DejaVu Sans", "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--background);
  width: 100%;
  height: 100%;
  margin: 0;
  touch-action: pan-x pan-y pinch-zoom;
  filter: hue-rotate(0deg);
}

.container {
  background-color: var(--background);
  margin: auto;
  padding: 0px 10px;
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
}

.controls {
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  background: var(--background);
  position: absolute;
  display: flex;
  justify-content: space-between;
  align-items: stretch;
}

.chords {
  user-select: none;
  touch-action: none;
  background: rgba(0, 0, 0, 0.1);
  padding: 20px;
  display: flex;
  flex-direction: row;
  justify-content: center;
}

.chord-column {
  display: flex;
  flex-direction: column;
  justify-content: end;
}

.middle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

.bass {
  user-select: none;
  touch-action: none;
  background: rgba(0, 0, 0, 0.1);
  padding: 20px 40px;
  display: flex;
  flex-direction: row;
  align-items: flex-end;
  justify-content: center;
}

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

.button {
  height: 80px;
  width: 80px;
  border-radius: 20px;
  margin: 1px;
  background: var(--button);
  font-size: 36px;
  color: white;
  letter-spacing: -1px;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.fullscreen-button-area {
  position: absolute;
  top: 20px;
  right: 4px;
  z-index: 5;
  display: flex;
  flex-direction: column;
}

*:fullscreen .fullscreen-button-area,
.fullscreen-button-area:fullscreen {
  display: none;
}

.fullscreen-button-area button {
  min-width: 100px;
  min-height: 50px;
}

.fullscreen-button-area button.fullscreen-button {
  min-height: 100px;
  font-size: 110%;
}

.refresh-link {
  user-select: none;
  position: absolute;
  top: 4px;
  right: 4px;
  z-index: 5;
}

input[type="range"][orient="vertical"] {
  writing-mode: bt-lr;
  /* IE */
  -webkit-appearance: slider-vertical;
  /* WebKit */
  width: 12px;
  height: 80%;
  padding: 0 5px;
}

#settings {
  position: absolute;
  top: 4px;
  left: 4px;
  z-index: 5;
}

/* Make the settings non-tabbable when hidden */
#settings:not(:checked) ~ a,
#settings:not(:checked) ~ select,
#settings:not(:checked) ~ input {
  display: none;
}

label {
  user-select: none;
}

label[for="settings"] {
  position: absolute;
  top: 4px;
  left: 30px;
  z-index: 5;
}

#settings:checked ~ .controls {
  pointer-events: none;
  opacity: 0.2;
}

#split-keys:checked ~ .controls .button.bass-button {
  background: linear-gradient(
    to bottom,
    var(--button) 65%,
    var(--button-split) 65%
  );
}

#horizontal-chords:checked ~ .controls .chords {
  flex-direction: column;
}

#horizontal-chords:checked ~ .controls .chord-column {
  flex-direction: row;
}