.container-header {
      background-color: #8dd6f7;
      background-image: none;
    }
.container-header .navbar-brand {
    color: #fa8e2e;
    margin-left: auto;
    margin-right: auto;
    font-size: 3rem;
}
.container-header .navbar-brand a {
    color: #fa8e2e;
    text-decoration: none;
    font-weight: 600;
}
.card {
  border: none;
  border-radius: 6px;
  overflow: visible; /* wichtig, damit das Fähnchen oben nicht abgeschnitten wird */
}

.card-header {
  background: linear-gradient(to bottom, #6d8fc4 0%, #35538a 100%);
  border: 1px solid #2c4570;
  border-radius: 6px 6px 0 0;
  padding: 10px 15px 10px 30px;
  overflow: visible;
}

.card-header h3,
.card-header .card-title {
  color: #fff;
}

/* Fähnchen / Ribbon-Icon oben links */
.card-header::before {
  content: "";
  position: absolute;
  top: -6px;
  left: 10px;
  width: 14px;
  height: 14px;
  background: #a9c3e0;
  border: 1px solid #2c4570;
  transform: rotate(45deg);
  z-index: 2;
}

.card-header::after {
  content: "";
  position: absolute;
  top: 4px;
  left: 12px;
  width: 10px;
  height: 8px;
  background: #6d8fc4;
  clip-path: polygon(0 0, 100% 0, 50% 100%);
  z-index: 3;
}