style(host-detail): centre host title, move delete button to bottom-right

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

style/rust-ipam.css

@@ -1043,6 +1043,24 @@ td.col-actions {
   gap: var(--size-xs);
 }
 
+/* Detail page header: back button then centred title */
+.detail-page-header {
+  flex-direction: column;
+  align-items: center;
+  gap: var(--size-xs);
+}
+
+/* Self-align the back button to the left while the title stays centred */
+.detail-page-header .back-btn {
+  align-self: flex-start;
+}
+
+.detail-page-title {
+  text-align: center;
+  width: 100%;
+  margin: 0;
+}
+
 .back-btn {
   display: inline-flex;
   align-items: center;
@@ -1182,3 +1200,10 @@ td.col-actions {
   width: 200px;
   flex-shrink: 0;
 }
+
+/* Delete button anchored to the bottom-right of the detail page */
+.danger-zone {
+  display: flex;
+  justify-content: flex-end;
+  margin-top: var(--size-lg);
+}