style.css

body {
  margin: 0;
  overscroll-behavior: none; /* Disable Chrome two fingers back/forward swipe */
  user-select: none;  /* Prevent accidental selection while dragging mouse */
  
  background-color: black;
  color: white;
}

.center {
  display: flex;
  justify-content: center;
}

.speed {
  position: absolute;
  padding: 4px;
  font: 18px Arial, sans-serif;
}

#title {
  position: absolute;
  top: 50%;
  transform: translate( 0%, -50% );
  font: 28px Arial, sans-serif;
}

#instructions {
  position: absolute;
  display: inline;
  bottom: 4px;
  font: 10px Arial, sans-serif;
}

.key {
  display: inline-block;
  min-width: 15px;
  border: 3px outset gray;
  background: gray;
  color: white;
  font-family: monospace;
  text-align: center;
}

.action {
  padding: 0px 20px 0px 10px;
}