body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f9f9f9;
}
header {
  background-color: #1a73e8;
  color: white;
  padding: 20px;
  text-align: center;
}
nav {
  margin-top: 10px;
}
nav a {
  color: white;
  margin: 0 15px;
  text-decoration: none;
  font-weight: bold;
}
main {
  padding: 40px 20px;
  text-align: center;
}
.plan-card {
  display: inline-block;
  background: white;
  border-radius: 10px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  padding: 20px;
  margin: 20px;
  width: 200px;
}
.plan-card button {
  background-color: #1a73e8;
  color: white;
  border: none;
  padding: 10px 20px;
  border-radius: 6px;
  cursor: pointer;
}
footer {
  background-color: #333;
  color: white;
  text-align: center;
  padding: 15px;
}

@media (max-width: 768px) {
  nav a {
    display: block;
    margin: 10px 0;
  }

  main {
    padding: 20px;
  }

  .plan-card {
    width: 90%;
    margin: 10px auto;
    display: block;
  }
}

@media (max-width: 480px) {
  header h1 {
    font-size: 24px;
  }

  .plan-card {
    padding: 15px;
  }

  .plan-card h3 {
    font-size: 18px;
  }

  .plan-card p {
    font-size: 16px;
  }

  .plan-card button {
    width: 100%;
    font-size: 16px;
  }
}