* {
  box-sizing: border-box;
}

body {
  background: radial-gradient(circle at top, #1a1f3a, #0f1222 60%);
  color: white;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  height: 100vh;
  margin: 0;
  display: flex;
  justify-content: center;
  align-items: center;
}

#app {
  width: 100%;
  max-width: 480px;
  padding: 20px;
  text-align: center;
}

h1 {
  margin-bottom: 6px;
  font-size: 28px;
}

#status {
  margin-bottom: 14px;
  font-size: 14px;
  opacity: 0.85;
}

.videos {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 16px;
}

video {
  width: 100%;
  height: 240px;
  background: #000;
  border-radius: 14px;
  object-fit: cover;
  border: 1px solid rgba(255,255,255,0.08);
}

/* Placeholder visual cuando no hay stream */
video:empty::before {
  content: "Cámara no conectada";
  color: #888;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  font-size: 12px;
}

.controls {
  display: flex;
  gap: 12px;
  justify-content: center;
}

button {
  padding: 12px 20px;
  border-radius: 12px;
  border: none;
  cursor: pointer;
  font-weight: 600;
  font-size: 14px;
  transition: transform 0.1s ease, opacity 0.1s ease;
}

button:active {
  transform: scale(0.97);
}

button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

#btnStart {
  background: linear-gradient(135deg, #00e0b8, #00bfa6);
  color: #001d19;
}

#btnNext {
  background: linear-gradient(135deg, #ff4d6d, #ff2f5e);
  color: white;
}

/* Responsive para móviles chicos */
@media (max-width: 420px) {
  video {
    height: 180px;
  }

  h1 {
    font-size: 24px;
  }
}