:root {
  --primary: #2563eb;
  --dark: #0f172a;
  --bg: #f8fafc;
  --card: #ffffff;
}

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

body {
  font-family: 'Poppins', sans-serif;
  background: var(--bg);
  color: var(--dark);
  padding: 40px 20px;
}

h1 {
  text-align: center;
  font-size: 2.3rem;
  font-weight: 800;
  margin-bottom: 10px;
}

.subtitle {
  text-align: center;
  max-width: 600px;
  margin: 0 auto 50px auto;
  color: #64748b;
  font-size: 0.95rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
  max-width: 1100px;
  margin: auto;
}

.card {
  background: var(--card);
  border-radius: 16px;
  padding: 20px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.08);
  transition: 0.3s ease;
  border: 1px solid #e2e8f0;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 15px 35px rgba(0,0,0,0.12);
}

.card img {
  width: 100%;
  border-radius: 5px;
  margin-bottom: 15px;
}

.cert-info h3 {
  font-size: 1.1rem;
  margin-bottom: 5px;
}

.cert-info p {
  font-size: 0.85rem;
  color: #64748b;
  margin-bottom: 15px;
}

.btn-group {
  display: flex;
  gap: 10px;
}

button, .btn-link {
  flex: 1;
  padding: 10px;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  text-align: center;
  text-decoration: none;
  font-size: 0.85rem;
  transition: 0.2s;
}

.btn-download {
  background: var(--dark);
  color: white;
  border: none;
}

.btn-download:hover {
  background: black;
}

.btn-link {
  border: 2px solid #e2e8f0;
  color: var(--dark);
}

.btn-link:hover {
  background: #f1f5f9;
}

.about {
  margin-top: 80px;
  text-align: center;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.about h2 {
  font-size: 1.6rem;
  margin-bottom: 10px;
}

.about p {
  color: #64748b;
  font-size: 0.95rem;
  line-height: 1.6;
}


footer {
  margin-top: 80px;
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid #e2e8f0;
  font-size: 0.85rem;
  color: #64748b;
}


@media(max-width: 768px) {
  .grid {
    grid-template-columns: 1fr;
  }
}