body {
  background-color: var(--color-background);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  align-items: stretch;
  gap: 5vh;
  height: 100%;
  font-family: Arial, sans-serif;
  margin: 7.5vh 7.5vw;
}

.tools-container {
  width: 100%;
  display: flex;
  flex-direction: row;
  justify-content: space-evenly;
  gap: 2vh;
}

.calm-zone {
  height: 15vh;

  background-image: url("../icons/notes-line.png");
  background-size: contain;
  background-position: left;
  background-repeat: round;
}

.piano-container {
  width: 100%;
  height: 45vh;

  display: flex;
  flex-direction: row;
  justify-content: space-between;
  align-items: stretch;
  gap: 2.5vw;

  padding: 2vh;
  box-sizing: border-box;
}

button img {
  width: 65%;
  position: relative;
  z-index: 2;
}

.key-text {
  display: block;
  font-size: 2rem;
  color: var(--color-text);
}

.key-image {
  display: none;
  width: 80%;
  position: relative;
  z-index: 2;
}

.btn-sound {
  cursor: pointer;
  position: relative;
  overflow: hidden;

  width: var(--btn-round-size);
  height: var(--btn-round-size);
  border-radius: var(--btn-round-radius);
  background-color: var(--color-btn);
  border: none;
}

.activated .svg-round-border-animation .running-ring {
  stroke-dasharray: none;
  stroke-dashoffset: 0;
}

.piano-key {
  flex: 1;
  height: 100%;

  background-color: var(--color-btn);
  border: 1px solid var(--color-border);

  color: var(--color-text);

  /* Center content */
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

/* Assign different colors to each key */
.piano-key:nth-child(1) {
  background-color: #ff9999;
}
.piano-key:nth-child(2) {
  background-color: #ffcc99;
}
.piano-key:nth-child(3) {
  background-color: #ffff99;
}
.piano-key:nth-child(4) {
  background-color: #ccff99;
}
.piano-key:nth-child(5) {
  background-color: #99ffcc;
}
.piano-key:nth-child(6) {
  background-color: #99ccff;
}
.piano-key:nth-child(7) {
  background-color: #cc99ff;
}
.piano-key:nth-child(8) {
  background-color: #ff99cc;
}