app/views/_flash.html.erb
<% if alert %>
<div class="alert alert-danger d-flex align-items-center" role="alert">
<i class="fa-solid fa-triangle-exclamation"></i> <%= alert %>
</div>
<% elsif notice %>
<div class="alert alert-success d-flex align-items-center" role="alert">
<i class="fa-solid fa-circle-exclamation"></i> <%= notice %>
</div>
<% end %>