fix(tabs): container type should be auto-width by default

css/_tabs.scss

@@ -102,3 +102,22 @@
 @include exports('tabs-container-disabled-hover') {
   @include tabs-container-disabled-hover;
 }
+
+/// Container type: do not apply fixed 10rem width to nav links.
+/// Default tabs get width: 10rem at 42rem viewport from base Carbon styles
+/// (including :focus and :active); container tabs should size naturally.
+/// @access private
+/// @group components
+@mixin tabs-container-nav-link-width {
+  @media (min-width: 42rem) {
+    .#{$prefix}--tabs--container .#{$prefix}--tabs__nav-link,
+    .#{$prefix}--tabs--container .#{$prefix}--tabs__nav-link:focus,
+    .#{$prefix}--tabs--container .#{$prefix}--tabs__nav-link:active {
+      width: auto;
+    }
+  }
+}
+
+@include exports('tabs-container-nav-link-width') {
+  @include tabs-container-nav-link-width;
+}

docs/src/pages/components/Tabs.svx

@@ -104,7 +104,7 @@ Use the `icon` prop to render an icon next to the tab label. The icon is rendere
 
 ## Container type
 
-Use the container type for a more prominent tab interface.
+Use the container type for a more prominent tab interface. By default, container types have an auto-width.
 
 <Tabs type="container">
   <Tab label="Tab label 1" />
@@ -117,6 +117,21 @@ Use the container type for a more prominent tab interface.
   </svelte:fragment>
 </Tabs>
 
+## Container type (full width)
+
+Combine `type="container"` with `fullWidth` for container tabs that evenly span the full width of the container.
+
+<Tabs type="container" fullWidth>
+  <Tab label="Tab label 1" />
+  <Tab label="Tab label 2" />
+  <Tab label="Tab label 3" />
+  <svelte:fragment slot="content">
+    <TabContent>Content 1</TabContent>
+    <TabContent>Content 2</TabContent>
+    <TabContent>Content 3</TabContent>
+  </svelte:fragment>
+</Tabs>
+
 ## Container type (disabled)
 
 Container type tabs with disabled states. Set `disabled` to `true` on individual tabs to prevent interaction.