app/views/people/_form.html.erb
<div class="row">
<%= form.input :name, wrapper_html: { class: 'col-md-5' } %>
<%= form.input :gender, collection: [:Male, :Female], wrapper_html: { class: 'col-md-3' } %>
<%= form.input :date_of_birth, as: :string, wrapper_html: { class: 'col-md-4' }, input_html: { class: 'datepicker' } %>
</div>
<div class="row">
<%= form.input :phone, wrapper_html: { class: 'col-md-6' } %>
<%= form.input :email, wrapper_html: { class: 'col-md-6' } %>
</div>
<div class="row">
<%= form.input :address, wrapper_html: { class: 'col-md-12' } %>
</div>