html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

.foresta {
  position: relative;
  width: 100%;
  height: 100vh;
  background-color: #e2f4d1;
  overflow: hidden;
}
/* Albero */
.albero {
  position: absolute;
  width: 50px;
  height: 70px;
  background-color: #2e8b57;
  border-radius: 25px 25px 0 0;
  border: 2px solid #14532d;
  z-index: 2; /* SOPRA le persone */
}

/* Persona */
.persona {
  position: absolute;
  width: 20px;
  height: 20px;
  background-color: orange;
  border-radius: 50%;
  pointer-events: none;
  z-index: 1; /* SOTTO gli alberi */
  transition: top 3s linear, left 3s linear;
}

/* Roccia */
.roccia {
  position: absolute;
  width: 40px;
  height: 25px;
  background-color: #888;
  border-radius: 50%;
  border: 2px solid #555;
  z-index: 0;
}