.card-container {
  margin: 20px 0;
  padding: 15px;
  border: 1px solid #ddd;
  border-radius: 8px;
}

/* Base layout - works everywhere */
.progressive-cards {
  list-style: none;
  padding: 0;
  margin: 0;
}

.progressive-cards li {
  margin-bottom: 15px;
  padding: 15px;
  background: #f8f9fa;
  border: 1px solid #dee2e6;
  border-radius: 6px;
}

/* Enhanced with Flexbox */
@supports (display: flex) {
  .progressive-cards {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
  }
  
  .progressive-cards li {
    flex: 1 1 calc(50% - 7.5px);
    margin-bottom: 0;
  }
}

/* Even better with Grid */
@supports (display: grid) {
  .progressive-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 15px;
  }
  
  .progressive-cards li {
    flex: none;
  }
}

.feature-indicator {
  display: inline-block;
  padding: 4px 8px;
  font-size: 12px;
  border-radius: 4px;
  background: #007bff;
  color: white;
  margin-left: 10px;
}