Prototype impact header different image size

- modify the impact header on desktop to remove the specific sizing of the image to be square
- the best way to do this without breaking any existing images seems to be to remove the height specifications and rely on the image dimensions
- to allow for this we remove the vertical centering of the text on the left, and apply top padding instead
- this allows us to refactor the caption markup so it sits beneath the image (previously this had to be separate because the expanded details element would cause the text on the left to move with the changing height of the overall component)

Author: andysellick

app/assets/images/flexible-pages/example_desktop_1x_landscape.jpg

@@ -5,25 +5,6 @@ $gap: 30px;
   margin-bottom: 30px;
 }
 
-.app-c-impact-header__caption-wrapper {
-  max-width: 1020px;
-  margin: 0 auto;
-
-  @include govuk-media-query($from: desktop) {
-    display: flex;
-    gap: $gap;
-
-    &::before {
-      content: "";
-      display: block;
-      height: 1px;
-      width: 50%;
-      flex-shrink: 1;
-      max-width: 495px;
-    }
-  }
-}
-
 .app-c-impact-header__caption {
   padding: 15px;
 
@@ -33,8 +14,7 @@ $gap: 30px;
 
   @include govuk-media-query($from: desktop) {
     box-sizing: border-box;
-    width: 50%;
-    padding-left: 0;
+    padding: 30px 0;
   }
 }
 
@@ -47,17 +27,13 @@ $gap: 30px;
   @include govuk-media-query($from: desktop) {
     flex-direction: row;
     gap: $gap;
-    min-height: $box-size;
   }
 }
 
 .app-c-impact-header__detail {
   padding: 15px;
   flex-shrink: 1;
   flex-grow: 0;
-  display: flex;
-  flex-direction: column;
-  justify-content: center;
 
   @include govuk-media-query($from: tablet) {
     padding: 30px;
@@ -66,25 +42,25 @@ $gap: 30px;
   @include govuk-media-query($from: desktop) {
     box-sizing: border-box;
     width: 50%;
-    padding: 30px 0 30px 30px;
+    padding: 60px 0 30px 30px;
   }
 }
 
 .app-c-impact-header__image-wrapper {
   flex-shrink: 1;
   flex-grow: 0;
-  overflow: hidden;
-  display: flex;
-  align-items: center;
-  justify-content: flex-start;
-  aspect-ratio: 16 / 9;
   box-sizing: border-box;
 
   @include govuk-media-query($from: desktop) {
     width: 50%;
-    aspect-ratio: auto;
     max-width: $box-size;
-    align-self: flex-end;
+    align-self: flex-start;
+  }
+}
+
+.app-c-impact-header__image-thing {
+  @include govuk-media-query($from: desktop) {
+    overflow: hidden;
   }
 }
 
@@ -94,7 +70,6 @@ $gap: 30px;
   margin: 0 auto;
 
   @include govuk-media-query($from: desktop) {
-    max-height: $box-size;
     max-width: none;
   }
 }

app/assets/images/flexible-pages/example_desktop_2x_landscape.jpg

@@ -36,32 +36,40 @@
     } %>
   <% end %>
 
+  <% caption = capture do %>
+    <% if show_caption %>
+      <div class="app-c-impact-header__caption">
+        <%= render "govuk_publishing_components/components/details", {
+          title: "Image details",
+          theme: ("black" unless inverse),
+          inverse: inverse,
+          margin_bottom: 0,
+        } do %>
+          <%= image[:caption] %>
+        <% end %>
+      </div>
+    <% end %>
+  <% end %>
+
   <%= tag.div(**component_helper.all_attributes) do %>
     <% if image %>
       <div class="app-c-impact-header__container">
         <div class="app-c-impact-header__detail">
           <%= text %>
         </div>
 
-        <%= render "flexible_page/flexible_sections/shared/picture",
-          image: image,
-          style: "app-c-impact-header",
-          alt_text: "" %>
-      </div>
-      <% if show_caption %>
-        <div class="app-c-impact-header__caption-wrapper">
-          <div class="app-c-impact-header__caption">
-            <%= render "govuk_publishing_components/components/details", {
-              title: "Image details",
-              theme: ("black" unless inverse),
-              inverse: inverse,
-              margin_bottom: 0,
-            } do %>
-              <%= image[:caption] %>
+        <div class="app-c-impact-header__image-wrapper">
+          <div class="app-c-impact-header__image-thing">
+            <%= picture_tag(class: "") do %>
+              <%= tag.source srcset: srcset_string(:desktop, image), media: "(min-width: 769px)" %>
+              <%= tag.source srcset: srcset_string(:tablet, image), media: "(min-width: 641px) and (max-width: 768px)" %>
+              <%= tag.source srcset: srcset_string(:mobile, image), media: "(max-width: 640px)" %>
+              <%= image_tag(image[:sources][:desktop], class: "app-c-impact-header__image", alt: "") %>
             <% end %>
           </div>
+        <%= caption %>
         </div>
-      <% end %>
+      </div>
     <% else %>
       <div class="app-c-impact-header__grid">
         <div class="govuk-grid-row">

app/assets/stylesheets/components/_impact-header.scss

@@ -32,6 +32,20 @@ examples:
           tablet_2x: "/assets/frontend/flexible-pages/example_tablet_2x.jpg"
     context:
       full_width: true
+  with_smaller_image:
+    data:
+      heading: This is the title of the impact header
+      description: This is the description of the impact header, containing words that form a paragraph of text.
+      image:
+        sources:
+          desktop: "/assets/frontend/flexible-pages/example_desktop_1x_landscape.jpg"
+          desktop_2x: "/assets/frontend/flexible-pages/example_desktop_2x_landscape.jpg"
+          mobile: "/assets/frontend/flexible-pages/example_mobile_1x.jpg"
+          mobile_2x: "/assets/frontend/flexible-pages/example_mobile_2x.jpg"
+          tablet: "/assets/frontend/flexible-pages/example_tablet_1x.jpg"
+          tablet_2x: "/assets/frontend/flexible-pages/example_tablet_2x.jpg"
+    context:
+      full_width: true
   with_image_caption:
     data:
       heading: With image caption