= form_with model: @offline, url: "/public/#{@contest.id}/offline" do |form|
  .row.mb-3
    .col
      .form-text.mb-1
        = t("puzzles.image_select")
      = form.file_field :start_image, accept: "image/*", class: "form-control"
      .form-text.error-message style="display: none;" id="image-error-message"
        = t("puzzles.form.file_too_big")
      javascript:
        function setMaxUploadSize() {
          const el = document.querySelector('input[type="file"]');
          el.onchange = function() {
            if(this.files[0].size > 2 * 1024 * 1024) {
              document.getElementById('image-error-message').style.display = 'block';
              this.value = "";
            } else {
              document.getElementById('image-error-message').style.display = 'none';
            }
          };
        }

        setMaxUploadSize();
  .row.mt-3
    .col
      = form.submit t("helpers.buttons.add"), class: "btn btn-primary"