= form_for memo do |f|
  .box-body
    .row
      .col-sm-6.form-group
        = f.label :description
        = f.text_area :description, rows: 20, class: "form-control markdown-editor", data: { target: ".description-preview" }
      .col-sm-6.form-group
        %label Preview
        .markdown-block.description-preview
          = memo.description_html
  .box-footer
    = f.button "Update", class: "btn btn-primary"

= form_for memo do |f|
  .box-body
    .row
      .col-sm-6.form-group
        = f.label :description
        = f.text_area :description, rows: 20, class: "form-control markdown-editor", data: { target: ".description-preview" }, tabindex: 1
      .col-sm-6.form-group
        %label Preview
        .markdown-block.description-preview
          = memo.description_html
  .box-footer
    = f.button "Update", class: "btn btn-primary", tabindex: 2

Set submit button tabindex after textarea
Set submit button tabindex after textarea
