* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background-color: #143f6b;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

.piano {
  display: flex;
}

.key {
  height: calc(var(--width) * 4);
  width: var(--width);
}

.white {
  --width: min(10vw, 100px);
  background-color: white;
  border: 1px solid #333;
}

.white.active {
  background-color: #ccc;
}

.black {
  --width: min(6vw, 60px);
  background-color: black;
  margin-left: calc(var(--width) / -2);
  margin-right: calc(var(--width) / -2);
  z-index: 1;
}

.black.active {
  background-color: #333;
}

.footer {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  text-align: center;
  font-family: "Open Sans", sans-serif;
  color: #f5f5f5;
  background-color: black;
  padding: 10px 0px;
  font-size: min(2vw, 15px);
  position: fixed;
  left: 0px;
  bottom: 0px;
  width: 100%;
}