:root {
    --primary-color: #0953a7;
    --secondary-color: #30d284;
    --text-color: #3d556f;
    --background: #f9f9f9;
    --card-bg: #ffffff;
    --border-radius: 12px;
    --error-color: #e32d3b;
  }

  * {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }

  body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    color: var(--text-color);
    background: var(--background);
    line-height: 1.6;
  }

  #heatpump-configurator {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
  }

  .configurator-header {
    text-align: center;
    margin-bottom: 30px;
  }

  .configurator-header h1 {
    font-size: 28px;
    color: var(--primary-color);
    margin-bottom: 10px;
  }

  .configurator-header p {
    font-size: 16px;
    color: var(--text-color);
  }

  .progress-container {
    margin-bottom: 30px;
  }

  .progress-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
  }

  .progress-text {
    font-size: 14px;
    font-weight: 600;
    color: var(--primary-color);
  }

  .progress-bar {
    width: 100%;
    height: 8px;
    background: #e0e0e0;
    border-radius: 4px;
    overflow: hidden;
  }

  .progress-fill {
    height: 100%;
    background: var(--secondary-color);
    transition: width 0.3s ease;
  }

  .step-container {
    display: none;
    animation: fadeIn 0.3s ease;
  }

  .step-container.active {
    display: block;
  }

  @keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
  }

  .step-title {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 25px;
    text-align: center;
    color: var(--primary-color);
  }

  .options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 15px;
    margin-bottom: 30px;
  }

  .option-card {
    background: var(--card-bg);
    border: 2px solid #e0e0e0;
    border-radius: var(--border-radius);
    padding: 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    min-height: 140px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
  }

  .option-card:hover {
    border-color: var(--secondary-color);
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
  }

.option-card.selected {
    border-color: var(--secondary-color);
    background: #f0fdf4; /* Hintergrund, um es deutlicher zu machen */
    /* Optional: Ein leichter Schatten */
    box-shadow: 0 0 0 3px rgba(48, 210, 132, 0.4); 
}

  .option-card .icon {
    font-size: 40px;
    margin-bottom: 10px;
  }

  .option-card .label {
    font-size: 15px;
    font-weight: 500;
  }

  .form-group {
    margin-bottom: 20px;
  }

  .form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    font-size: 14px;
  }

  .form-group label.required::after {
    content: " *";
    color: var(--error-color);
  }

  .form-group input,
  .form-group textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 15px;
    transition: border-color 0.3s ease;
  }

  .form-group input:focus,
  .form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
  }

  .form-group.error input {
    border-color: var(--error-color);
  }

  .error-message {
    color: var(--error-color);
    font-size: 13px;
    margin-top: 5px;
  }

  .form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
  }

  .checkbox-group {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    margin-top: 20px;
  }

  .checkbox-group input[type="checkbox"] {
    width: auto;
    margin-top: 4px;
  }

  .checkbox-group label {
    font-size: 13px;
    line-height: 1.5;
  }

  .step-navigation {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 12px;
    margin-top: 30px;
    flex-wrap: wrap;
  }

  .nav-arrow {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: #f0f0f0;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    transition: all 0.3s ease;
    color: var(--text-color);
  }

  .nav-arrow:hover:not(:disabled):not(.hidden) {
    background: var(--primary-color);
    color: white;
    transform: scale(1.1);
  }

  .nav-arrow:disabled {
    opacity: 0.3;
    cursor: not-allowed;
  }

  .nav-arrow.hidden {
    visibility: hidden;
    pointer-events: none;
  }

  .step-dots {
    display: flex;
    gap: 8px;
  }

  .step-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: #d9d9d9;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
  }

  .step-dot:hover:not(.disabled) {
    background: #b0b0b0;
    transform: scale(1.2);
  }

  .step-dot.completed {
    background: var(--secondary-color);
  }

  .step-dot.active {
    background: var(--primary-color);
    transform: scale(1.3);
  }

  .step-dot.disabled {
    cursor: not-allowed;
    opacity: 0.4;
  }

  .navigation-buttons {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-top: 30px;
  }

  .btn {
    padding: 14px 30px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
  }

  .btn-primary {
    background: var(--primary-color);
    color: white;
    min-width: 200px;
  }

  .btn-primary:hover {
    background: #073d7a;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(9, 83, 167, 0.3);
  }

  .btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
  }

  .success-screen {
    text-align: center;
    padding: 40px 20px;
  }

  .success-screen .icon {
    font-size: 80px;
    color: var(--secondary-color);
    margin-bottom: 20px;
  }

  .success-screen h2 {
    font-size: 26px;
    color: var(--primary-color);
    margin-bottom: 15px;
  }

  .success-screen p {
    font-size: 16px;
    color: var(--text-color);
    line-height: 1.8;
  }

  @media (max-width: 600px) {
    .options-grid { grid-template-columns: repeat(2, 1fr); }
    .form-row { grid-template-columns: 1fr; }
    .configurator-header h1 { font-size: 24px; }
    .navigation-buttons {
      position: sticky;
      bottom: 0;
      background: var(--background);
      padding: 15px 0;
      margin: 0 -20px;
      padding-left: 20px;
      padding-right: 20px;
      box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
    }
  }