@media (max-width: 768px) {
  .site-header { position: relative; }
  .main-nav { display: none; }
  .main-nav.is-open {
    display: flex;
    flex-direction: column;
    gap: 0;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-background);
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 8px 16px -8px rgba(0, 0, 0, 0.1);
    z-index: 20;
  }
  .main-nav.is-open a {
    padding: 14px 16px;
    border-top: 1px solid var(--color-border);
    font-size: 15px;
  }
  .main-nav.is-open a.is-active { background: var(--color-surface); }
  .menu-button { display: block; min-width: 44px; min-height: 44px; }
  .hero { padding: 56px 0; }
  .hero h1 { font-size: 36px; }
  .hero p { font-size: 16px; }
  .tools-grid { grid-template-columns: 1fr; }
  .footer-content { grid-template-columns: 1fr 1fr; }
  .compressor-workspace { grid-template-columns: 1fr; }
  .compressor-preview { border-right: none; border-bottom: 1px solid var(--color-border); }
  .compressor-preview img { height: 220px; }
  .qr-canvas-wrap { min-height: 220px; }
  .text-tool-columns { grid-template-columns: 1fr; }
}
@media (max-width: 480px) {
  .footer-content { grid-template-columns: 1fr; }
  .compressor-dropzone { padding: 32px 16px; }
  .compressor-actions { flex-direction: column; align-items: stretch; }
  .compressor-actions .btn { width: 100%; }
  .resizer-dimensions { flex-direction: column; gap: 20px; }
  .qr-field-row { flex-direction: column; gap: 20px; }
  .pw-output-row { flex-direction: column; align-items: stretch; }
  .pw-output-row .btn { width: 100%; }
  .pdf-file-item { flex-wrap: wrap; }
  .pdf-file-actions { width: 100%; justify-content: flex-end; }
  .pdf-results-header { flex-direction: column; align-items: stretch; }
  .pdf-results-header .btn { width: 100%; }
  .pdf-page-grid { grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); }
  .text-tool-actions { flex-direction: column; align-items: stretch; }
  .text-tool-actions .btn { width: 100%; }
  .text-tool-limit-row { flex-direction: column; align-items: stretch; }
  .donut-section { flex-direction: column; text-align: center; }
  .donut { margin: 0 auto; }
  .donut-legend { width: 100%; }
  .emi-amort-header { flex-direction: column; align-items: stretch; }
  .emi-toggle-group .emi-toggle-btn { flex: 1; }
  .age-dob-group { flex-wrap: wrap; }
}