body {
  font-family: "Segoe UI", sans-serif;
  background: #f4f6f8;
  margin: 0;
  padding: 0;
  color: #333;
}
header {
  text-align: center;
  background: #0078d7;
  color: white;
  padding: 20px;
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 15px;
  padding: 20px;
}
.card {
  background: white;
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  text-align: center;
}
.status {
  margin-top: 10px;
  font-weight: bold;
}
.status.on { color: green; }
.status.off { color: red; }
