[css-grid] grid area as element

I love the idea of grid areas to place items. They reduce the need for layout wrapper elements that have no semantic meaning. However, I still require wrapper elements for nested layouts, e.g. a dynamic flex layout inside a grid cell.

I would love to be able to target a grid area and use and style it just like a wrapper element. I don't know if this is feasible at all, but this would (in most cases) completely eliminate the need for any layout wrapper elements.

As an example markup:

<div class="grid">
  <div class="header">...</div>
  <div class="menu">...</div>
  <div class="footer">...</div>
  <div class="content">...</div>
  <div class="content">...</div>
  <div class="content">...</div>
  <div class="content">...</div>
</div>

The css:

.grid {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-rows: auto 1fr auto;
  grid-template-areas:
    'header  content'
    'menu    content'
    'footer  content';
}

.grid:grid-area(content) {
  display: flex;
  flex-wrap: wrap;
  outline: 1px solid black;
}

.header {
  grid-area: header;
}

.menu {
  grid-area: menu;
}

.content {
  grid-area: content;
}

.footer {
  grid-area: footer;
}

As a result, the DOM structure is completely flattened and only contains actual content. The css completely controls the layout, including the nested dynamic flow of the .content items.

Using the (suggested) accessor :grid-area, the items within this area are placed using a flex flow and wrapped when needed. It would then also be possible to style the area even further as shown with the black border.

Again, I do not know if this is even technically possible with the current implementation of grid, but, to me, this looks like the missing link to combine the power of grid and flexbox.

[edit: updated css suggested selector to :grid-area]

Start by reading the CSS Grid and flexbox behavior described in the issue, focusing on the proposed :grid-area accessor and how it would target an area rather than an element. Determine whether the requested nested flex layout and area styling are technically feasible, then document a concrete specification direction and its expected behavior.