diff --git a/templates/artifacts/feed.html b/templates/artifacts/feed.html
index 5c37acb..c482a60 100644
--- a/templates/artifacts/feed.html
+++ b/templates/artifacts/feed.html
@@ -131,6 +131,15 @@
       if (!feed) return;
       let selectedView = "{{ selected_view }}";
 
+      // When a single source is selected, the row's source column is dropped
+      // (see .no-source-col), so the artifact sidebar needs ~7rem less width.
+      // The stored width is the "all sources" (wide) width; a selected source
+      // renders it minus this fixed offset. Dragging the splitter in either
+      // mode adjusts the stored width directly, so the width is settable in
+      // whichever mode you're in and the other mode tracks it by the offset.
+      const SOURCE_COL_WIDTH = 112; // 7rem, matches the dropped source column
+      const sourceSelected = Boolean(feed.dataset.selectedSource);
+
       const sizes = {
         days: Number(localStorage.getItem("daybook.daysWidth")) || 144,
         artifacts: Number(localStorage.getItem("daybook.artifactsWidth")) || 280,
@@ -138,7 +147,10 @@
 
       const applySizes = () => {
         feed.style.setProperty("--days-width", `${sizes.days}px`);
-        feed.style.setProperty("--artifacts-width", `${sizes.artifacts}px`);
+        const artifactsWidth = sourceSelected
+          ? Math.max(150, sizes.artifacts - SOURCE_COL_WIDTH)
+          : sizes.artifacts;
+        feed.style.setProperty("--artifacts-width", `${artifactsWidth}px`);
       };
 
       applySizes();