body {
    font-family: Arial, sans-serif;
    background-color: #f5f5f5;
    color: #333;
    padding: 2rem;
}
h1 {
    color: #007acc;
}
.gruppen-spalten {
  display: flex;
  justify-content: center;
  gap: 40px;
  margin-top: 30px;
}
.gruppen-spalte {
  background: rgba(255,255,255,0.8);
  padding: 20px;
  border-radius: 8px;
  min-width: 180px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  text-align: center;
}
.gruppen-spalte h2 {
  margin-bottom: 16px;
}
.gruppen-button {
  display: block;
  margin: 10px 0;
  background: #1976d2;
  color: #fff;
  padding: 12px 0;
  border-radius: 6px;
  text-decoration: none;
  font-weight: bold;
  transition: background 0.2s;
}
.gruppen-button:hover {
  background: #1565c0;
  color: #ffd600;
}