Stepper

<%# Stepper is a BLOCK, not a component: neither shadcn nor Base UI
    ships one, so the pattern lives here as copy-in source - adapt the
    steps freely; nothing hides behind an API. The server owns step state:
    pass step: as a local, or let it ride ?step= - Back/Continue are plain
    links that re-render, and completed steps are links back. In a real
    flow, swap the query param for your wizard's own routes/model state
    and the final action for a form submit. %>
<% steps = ["Shipping", "Payment", "Review"] %>
<% step = (local_assigns[:step] || params[:step] || 2).to_i.clamp(1, steps.length) %>
<% panels = {
     1 => ["Shipping", "Step 1 of 3 - where this order lands.",
           "Address fields mount here; this panel is the step's content slot."],
     2 => ["Payment", "Step 2 of 3 - how this order gets paid.",
           "Card details are collected by the payment element that mounts here; this panel is the step's content slot."],
     3 => ["Review", "Step 3 of 3 - confirm and place the order.",
           "The order summary renders here - line items, shipping choice, and the charge that Place order will submit."]
   } %>
<% title, description, body = panels.fetch(step) %>
<div class="mx-auto max-w-2xl p-6">
  <nav aria-label="Progress">
    <ol class="flex items-center gap-3">
      <% steps.each_with_index do |label, index| %>
        <% number = index + 1 %>
        <% unless number == 1 %>
          <li aria-hidden="true" class="h-px min-w-8 flex-1 <%= number <= step ? "bg-primary" : "bg-border" %>"></li>
        <% end %>
        <% if number < step %>
          <%# Completed: filled indicator with a check, revisitable. %>
          <li class="flex items-center">
            <a href="?step=<%= number %>" class="flex items-center gap-3 rounded-md outline-none focus-visible:ring-2 focus-visible:ring-ring">
              <span class="flex size-8 items-center justify-center rounded-full bg-primary text-primary-foreground">
                <%= poetry_icon(name: :check, class: "size-4", label: "Completed") %>
              </span>
              <span class="text-sm font-medium"><%= label %></span>
            </a>
          </li>
        <% elsif number == step %>
          <%# Current: outlined in primary, named by aria-current. %>
          <li aria-current="step" class="flex items-center gap-3">
            <span class="flex size-8 items-center justify-center rounded-full border-2 border-primary text-sm font-semibold text-primary"><%= number %></span>
            <span class="text-sm font-medium"><%= label %></span>
          </li>
        <% else %>
          <%# Upcoming: muted and inert until reached. %>
          <li class="flex items-center gap-3">
            <span class="flex size-8 items-center justify-center rounded-full border border-border text-sm text-muted-foreground"><%= number %></span>
            <span class="text-sm text-muted-foreground"><%= label %></span>
          </li>
        <% end %>
      <% end %>
    </ol>
  </nav>

  <div class="mt-6">
    <%= poetry_card do |card| %>
      <% card.with_title { title } %>
      <% card.with_description { description } %>
      <div class="space-y-4 text-sm">
        <p><%= body %></p>
      </div>
      <% card.with_footer do %>
        <div class="flex w-full items-center justify-between">
          <% if step > 1 %>
            <%= poetry_button(tag: :a, href: "?step=#{step - 1}", variant: :outline) { "Back" } %>
          <% else %>
            <span></span>
          <% end %>
          <% if step < steps.length %>
            <%= poetry_button(tag: :a, href: "?step=#{step + 1}") { "Continue to #{steps[step].downcase}" } %>
          <% else %>
            <%# The terminal action: wire this to your submit. %>
            <%= poetry_button { "Place order" } %>
          <% end %>
        </div>
      <% end %>
    <% end %>
  </div>
</div>