table {
  border-collapse: separate; /* Wichtig! */
  border-spacing: 0;
  border: 3px solid #ccc; /* Rahmenfarbe */
  border-radius: 30px; /* Abrundung */
  overflow: hidden; /* Verhindert Überlappen des Hintergrunds */
}

/* Ecken oben links/rechts */
table tr:first-child th:first-child { border-top-left-radius: 30px; }
table tr:first-child th:last-child { border-top-right-radius: 30px; }

/* Ecken unten links/rechts */
table tr:last-child td:first-child { border-bottom-left-radius: 30px; }
table tr:last-child td:last-child { border-bottom-right-radius: 30px; }