.keyboard {
  position: fixed;
  left: 0;
  bottom: 0;
  width: 100%;
  padding: 5px 0;
  background-color: #004134;
  box-shadow: 0 0 50px rgba(0,0,0,0.5);
  user-select: none;
  transition: bottom 0.4s;
}

.keyboard-hidden {
  bottom: -100%;
}

.keyboard-line {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
}

.keyboard-key {
  position: relative;
  border-radius: 4px;
  border: none;
  background-color: rgba(255,255,255,0.2);
  color: #ffffff;
  font-size: 1.4rem;
  font-weight: bold;
  outline: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

.keyboard-key:active {
  background-color: rgba(255,255,255,0.12);
}

.keyboard-key-activatable::after {
  content: '';
  position: absolute;
  top: 8px;
  right: 8px;
  width: 8px;
  height: 8px;
  background-color: rgba(0,0,0,0.4);
  border-radius: 50%;
}

.keyboard-key-active::after {
  background-color: #00FF00;
}