html, body {
  margin: 0;
  padding: 0;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
  position: fixed;
  top: 0;
  left: 0;
  background-color: #000;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

#app {
  width: 100vw;
  height: 100vh;
  position: absolute;
  top: 0;
  left: 0;
}

.a-canvas,
a-scene video {
  width: 100vw !important;
  height: 100vh !important;
  object-fit: cover !important;
  position: absolute !important;
  top: 0 !important;
  left: 0 !important;
}

/* Pantalla de Inicio (Modal) */
#start-screen {
  position: fixed;
  inset: 0;
  background: rgba(10, 10, 10, 0.92);
  backdrop-filter: blur(12px);
  z-index: 1000000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.start-card {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.15);
  padding: 32px 24px;
  border-radius: 24px;
  text-align: center;
  max-width: 360px;
  width: 100%;
  color: #fff;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
}

.start-card h1 {
  font-size: 22px;
  margin-bottom: 12px;
  font-weight: 600;
}

.start-card p {
  font-size: 14px;
  color: #a1a1aa;
  margin-bottom: 24px;
  line-height: 1.5;
}

#start-btn {
  background: #3b82f6;
  color: #fff;
  border: none;
  padding: 14px 28px;
  font-size: 16px;
  font-weight: 600;
  border-radius: 14px;
  width: 100%;
  cursor: pointer;
  transition: transform 0.2s ease, background 0.2s ease;
}

#start-btn:active {
  transform: scale(0.96);
  background: #2563eb;
}

/* UI Flotante */
#ui-overlay {
  position: fixed;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 99999;
  background: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(8px);
  color: #fff;
  padding: 12px 24px;
  border-radius: 20px;
  font-size: 14px;
  pointer-events: none;
  border: 1px solid rgba(255, 255, 255, 0.2);
  text-align: center;
}

#fullscreen-btn {
  position: fixed;
  top: 18px;
  right: 18px;
  z-index: 99999;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: #fff;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}