body {
  margin:0;
  font-family: Arial;
  background:#000;
  color:#fff;
  text-align:center;
}

.hero {
  padding:100px 20px;
}

.btn {
  display:inline-block;
  padding:15px 30px;
  margin:10px;
  border-radius:12px;
  text-decoration:none;
  font-weight:bold;
  transition:0.3s;
}

.main {
  background:#fff;
  color:#000;
  animation: pulse 2s infinite;
}

.ghost {
  border:1px solid #fff;
  color:#fff;
}

@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

.card {
  margin:40px auto;
  max-width:600px;
  padding:20px;
  border:1px solid #333;
  border-radius:16px;
}

.grid {
  display:grid;
  gap:10px;
  padding:20px;
}

.item {
  border:1px solid #333;
  padding:15px;
  border-radius:10px;
}

.center {
  margin:50px;
}