background-image-for-specific-page.liquid

{% if request.path contains 'contact' %}
  <style>
    html, body,
    [id*='shopify-section']:not([id*='announcement']):not([id*='header']):not([id*='footer']) > [class*='background'] {
        background: url('replace-url') !important;
        background-size: cover !important;
        background-repeat: no-repeat !important;
    }
  </style>
{% endif %}