/* ===============================
   ESTILO LABORATORIO PURO
   =============================== */

body {
  margin: 0;
  background-color: #000000;
  color: #ffffff;
  font-family: Arial, Helvetica, sans-serif;
  text-align: center;
}

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

/* Ocultar elementos */
.hidden {
  display: none;
}

/* Instrucciones */
#instructions {
  font-size: 26px;
  max-width: 900px;
  line-height: 1.6;
}

#instructions ul {
  text-align: left;
  font-size: 24px;
}

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

/* Fijación central */
#fixation {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  font-size: 96px;
  font-weight: 600;
  z-index: 1;
}

/* ===============================
   ESTÍMULO AMARILLO DINÁMICO
   =============================== */

/* Base */
#stimulus {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  z-index: 2;
  background-color: yellow;
}

/* Tamaño (urgencia implícita) */
.size-small {
  width: 50px;
  height: 50px;
}

.size-medium {
  width: 80px;
  height: 80px;
}

.size-large {
  width: 110px;
  height: 110px;
}

/* Luminancia (saliencia visual) */
.lum-low {
  opacity: 0.45;
}

.lum-medium {
  opacity: 0.7;
}

.lum-high {
  opacity: 1.0;
}

/* Botones */
button {
  padding: 12px 20px;
  font-size: 18px;
  border-radius: 8px;
  border: none;
  cursor: pointer;
}