body {
  margin: 0;
  background: black;
  color: white;
  font-family: Arial, sans-serif;
  text-align: center;
}

#container{
  width: 100vw;
  height: 100vh;
  display:flex;
  flex-direction:column;
  justify-content:center;
  align-items:center;
  gap: 20px;
}

.hidden{ display:none; }

#instructions{
  font-size: 26px;
  max-width: 900px;
  line-height: 1.5;
}
#instructions ul{
  text-align:left;
  font-size: 24px;
}

/* Pantalla de tarea */
#task{
  position: relative;
  width: 100vw;
  height: 100vh;
}

#fixation{
  position:absolute;
  left:50%;
  top:50%;
  transform: translate(-50%,-50%);
  font-size: 90px;
  z-index: 1;
}

#stimulus{
  position:absolute;
  left:50%;
  top:50%;
  transform: translate(-50%,-50%);
  font-size: 140px;
  font-weight: 700;
  z-index: 2;
}

button{
  padding: 12px 18px;
  font-size: 18px;
  border-radius: 10px;
  border:none;
  cursor:pointer;
}