* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Poppins', sans-serif;
  background-color: #f3f4f6;
  color: #333;
  line-height: 1.6;
}

header {
  text-align: center;
  padding: 2rem 1rem;
  background-color: #1e293b;
  color: #fff;
}

header h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

main.cert-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  padding: 2rem;
}

.cert-card {
  background-color: #fff;
  border-radius: 10px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
  overflow: hidden;
  transition: transform 0.3s ease;
}

.cert-card:hover {
  transform: translateY(-5px);
}

.cert-card img {
  width: 100%;
  height: auto;
  display: block;
}

.cert-info {
  padding: 1rem;
}

.cert-info h2 {
  font-size: 1.2rem;
  color: #1e293b;
}

.cert-info p {
  margin: 0.5rem 0;
  color: #555;
}

.cert-btn {
  display: inline-block;
  margin-top: 0.5rem;
  padding: 0.5rem 1rem;
  background-color: #1e40af;
  color: #fff;
  text-decoration: none;
  border-radius: 6px;
  font-size: 0.9rem;
  transition: background 0.3s;
}

.cert-btn:hover {
  background-color: #2563eb;
}

footer {
  text-align: center;
  padding: 1rem;
  background-color: #1e293b;
  color: #fff;
  font-size: 0.9rem;
}