* {
  box-sizing: border-box;
}

:root {
  --background-color: steelblue;
  --clicked-color: salmon;
  --canvas-width: 300px;
  --canvas-height: 200px;
  --canvas-radius: 6px;
  --size-control-height: 32px;
  --base-x: 0px;
  --base-y: 0px;
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
}

#background {
  width: 100vw;
  height: 100vh;
  background: var(--background-color);
}

#background.is-flashing {
  animation: background-flash 1s linear;
}

@keyframes background-flash {
  from {
    background: var(--clicked-color);
  }

  to {
    background: var(--background-color);
  }
}

.canvas-item {
  position: fixed;
  left: 50%;
  top: 50%;
  width: var(--canvas-width);
  height: var(--canvas-height);
  transform: translate(
    -50%,
    -50%
  ) translate(
    calc(var(--base-x) + var(--x, 0px)),
    calc(var(--base-y) + var(--y, 0px))
  );
  z-index: 1;
  cursor: grab;
  pointer-events: auto;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}

.canvas-item.drag-area-includes-size-controls {
  height: calc(var(--canvas-height) + var(--size-control-height));
}

.canvas-item.is-dragging {
  cursor: grabbing;
}

.canvas-controls {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.55);
  border-radius: var(--canvas-radius) 0 var(--canvas-radius) var(--canvas-radius);
  opacity: 0;
  pointer-events: none;
  transition: opacity 160ms ease;
}

.canvas-item:hover .canvas-controls {
  opacity: 1;
  pointer-events: auto;
}

.canvas-item.drag-area-includes-size-controls .canvas-controls {
  inset: var(--size-control-height) 0 0 0;
}

.canvas-controls button {
  min-width: 44px;
  border: 0;
  padding: 8px 12px;
  background: transparent;
  color: white;
  font-size: 28px;
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
}

.canvas-item.is-playing .play-button,
.canvas-item.is-paused .pause-button {
  display: none;
}

.size-controls {
  position: absolute;
  top: 0;
  right: 0;
  display: flex;
  overflow: hidden;
  z-index: 2;
  background: rgba(0, 0, 0, 0.55);
  border-radius: 8px 8px 0 0;
  pointer-events: auto;
  transform: translateY(-100%);
}

.canvas-item.drag-area-includes-size-controls .size-controls {
  transform: none;
}

.size-controls button {
  width: 32px;
  height: var(--size-control-height);
  border: 0;
  padding: 0;
  background: transparent;
  color: white;
  font-size: 28px;
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
}

.tetrahedron-canvas {
  display: block;
  width: var(--canvas-width);
  height: var(--canvas-height);
  background: black;
  border-radius: var(--canvas-radius) 0 var(--canvas-radius) var(--canvas-radius);
}

.canvas-item.drag-area-includes-size-controls .tetrahedron-canvas {
  position: absolute;
  left: 0;
  bottom: 0;
}