* {
  margin: 0;
  padding: 0;
}

body {
  background: #212121;
  position: relative;
}
#ui {
  position: absolute;
  height: 10vh;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-evenly;
}
#addmass {
  width: 210px;
  display: flex;
  justify-content: space-between;
}

p {
  color: white;
  font-family: Arial;
}

canvas {
  position: absolute;
  top: 15vh;
  left: 5vw;
  display: block;
  background-color: #000000;
  border-radius: 20px;
}