#keyboard {
  height: 8rem;
  overflow: auto;
  cursor: pointer;
  display: flex;
  justify-content: space-around;
  border-radius: 0;
}

#keyboard ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  justify-content: center;
}

#keyboard ul li {
  width: 4rem;
  height: 6.854rem;
  display: flex;
  align-items: flex-end;
  text-transform: uppercase;
  padding-left: 0.4rem;
  padding-bottom: 0.236rem;
  border-bottom-right-radius: 10px;
  border-bottom-left-radius: 10px;
  box-sizing: border-box;
  background-color: var(--white-keys-color);
  color: var(--font-keys-color);
  text-shadow: 0 1px 0 #000000;
  border: 0.1rem solid #3c3c3c;
  box-shadow: inset 0 0.2rem 0.2rem rgba(255, 255, 255, 0.7),
    0 0.236rem 0.618rem rgba(0, 0, 0, 0.5);
  background: linear-gradient(
    to bottom,
    var(--white-keys-color) 0%,
    #e6e6e6 100%
  );
}

#keyboard ul li::after {
  content: "";
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 0.2rem;
  background: rgba(255, 255, 255, 0.6);
  box-shadow: inset 0 0.1rem 0.1rem rgba(0, 0, 0, 0.1);
  border-top-left-radius: 10px;
  border-top-right-radius: 10px;
}

#keyboard ul li.active {
  text-shadow: 0 1px 0 #ffffff;
  transform: perspective(100px) translateZ(-2px);
}

#keyboard ul li.accidental {
  position: relative;
  margin-left: -2rem;
  margin-right: -2rem;
  height: 4.236rem;
  background-color: var(--black-keys-color);
  text-shadow: 0 1px 0 #000000;
  border: 0.1rem solid #606060;
  box-shadow: inset 0 0.2rem 0.2rem rgba(255, 255, 255, 0.5),
    0 0.236rem 0.618rem rgba(0, 0, 0, 0.5);
  background: linear-gradient(
    to bottom,
    var(--black-keys-color) 0%,
    #1a1a1a 100%
  );
  z-index: 1;
}

#keyboard ul li.accidental::after {
  content: "";
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 0.2rem;
  box-shadow: inset 0 0.1rem 0.1rem rgba(255, 255, 255, 0.1);
  border-top-left-radius: 10px;
  border-top-right-radius: 10px;
}

#keyboard ul li.accidental.active {
  text-shadow: 0 1px 0 #4d4d4d;
  transform: perspective(1000px) rotateY(10deg);
}

#keyboard ul li:last-child {
  margin-right: 0;
}