body {
  font-family: 'Segoe UI', sans-serif;
  background: #f6f8fa;
  color: #333;
  margin: 0;
  padding: 0;
}

header {
  text-align: center;
  padding: 40px 20px;
  background: #0366d6;
  color: white;
}

h1 {
  margin-bottom: 10px;
}

main {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 20px;
  padding: 40px;
}

.file-card {
  background: white;
  border-radius: 8px;
  padding: 20px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.1);
  width: 280px;
  text-align: center;
  transition: transform 0.2s;
}

.file-card:hover {
  transform: scale(1.03);
}

.btn {
  display: inline-block;
  margin-top: 10px;
  background: #2ea44f;
  color: white;
  text-decoration: none;
  padding: 10px 20px;
  border-radius: 6px;
  transition: background 0.2s;
}

.btn:hover {
  background: #2c974b;
}

footer {
  text-align: center;
  padding: 20px;
  background: #e1e4e8;
  font-size: 14px;
  color: #555;
}