* {
  position: relative;
}

body {
  background-color: #3c3c3c;
  overflow: hidden;
  text-align: center;
  font-family: sans-serif;
}

body,
html {
  height: 100%;
  width: 100%;
  margin: 0;
  padding: 0;
}
h1 {
  color: #ccc;
  text-align: center;
}

.main {
  width: 100%;
  display: flex;
  justify-content: center;
  flex-direction: column;
  align-items: center;
}
.demo {
  visibility: hidden;
  width: 400px;
  height: 250px;
  background: #1d1d1d;
  overflow: hidden;
}

.slime {
  width: 80px;
  height: 50px;
  background-image: url("https://assets.codepen.io/32887/slime.svg");
  background-size: cover;
  position: absolute;
  /* background-color:red; */
  top: 100px;
  transform: translateX(-100%);
}

.buttonNav {
  padding: 20px;
}

button {
  margin-right: 10px;
  padding: 10px;
}