.form-grid, .result-columns { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; }
      .result-row { display: flex; justify-content: space-between; gap: 1rem; padding: .65rem 0; border-bottom: 1px solid var(--border-color, #ddd); }
      .status-box, .calculation-note { padding: 1rem; border-radius: .5rem; background: var(--surface-alt, #f5f7fa); }
      .error { color: #a01830; min-height: 1.5rem; }
      @media (max-width: 700px) { .form-grid, .result-columns { grid-template-columns: 1fr; } }