*{
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body{
  width: 100vw;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

#canvas{
  width: 100vw;
  height: 100vh;
  border: 4px solid blue;
  background-image: url('assets/background.png');
  background-repeat: no-repeat;
  background-size: cover;
  overflow: hidden;
}

#menu{
  position: absolute;
  width: 100vw;
  height: 100vh;
}
.btn{
  margin-bottom: 10px;
  background-color: black;
  color: white;
  position: relative;
  display: block;
  height: 30px;
  width: 100px;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  cursor: pointer;
}