The flow toolbar beside a panel sheds by the lane it sits in: below 440px the fit control, the separators and Run's caption, below 336px the console. Below 988px wide the sidebar folds while a panel is open, without touching the saved preference, and comes back when it closes; the view is aimed again once the sidebar has moved

frontend/src/components/Common/Dock.tsx

@@ -56,9 +56,12 @@ export function Dock({
 }
 
 /** Groups the dock's buttons; a phone wraps instead. */
-export function DockSeparator() {
+export function DockSeparator({ className }: { className?: string }) {
   return (
-    <Separator orientation="vertical" className="mx-0.5 !h-5 hidden md:block" />
+    <Separator
+      orientation="vertical"
+      className={cn("mx-0.5 !h-5 hidden md:block", className)}
+    />
   )
 }
 

frontend/src/components/Flow/FlowDock.tsx

@@ -53,6 +53,11 @@ export const FIT_VIEW_PANEL = {
   padding: { top: "10%", bottom: "10%", left: "10%", right: "432px" } as const,
 }
 
+/** Hidden in a lane narrower than the whole bar: the phone's cuts. */
+const SHED = "md:@max-[27.5rem]:hidden"
+/** Hidden in a lane narrower than that shorter bar. */
+const SHED_MORE = "md:@max-[21rem]:hidden"
+
 /**
  * The action bar, floating bottom-centre. Run is the one brand-secondary
  * affordance on this view; everything else stays quiet.
@@ -64,6 +69,11 @@ export const FIT_VIEW_PANEL = {
  * On a phone it is a bar across the bottom edge, which drops the fit control
  * and the caption on Run to leave the row room; otherwise it floats and wraps
  * rather than overflows. See DESIGN-GUIDELINES.md → Responsive.
+ *
+ * Beside a panel it is measured against the lane it sits in, not the screen.
+ * A lane too narrow for the editing bar (the issues badge and discard showing)
+ * sheds what a phone sheds, then the console. Below that the editor folds the
+ * sidebar away while the panel is open (`CRAMPED` in FlowEditor).
  */
 export function FlowDock({
   flow,
@@ -120,13 +130,14 @@ export function FlowDock({
     // half-pixel centring translate or its backdrop filter inside the other —
     // which is what Firefox was drawing the console's text through. It also
     // gives the two panels a row to share, instead of one landing on the other.
+    // The column spans the canvas lane, which is what `SHED` measures.
     <div
       className={cn(
-        "pointer-events-none absolute inset-x-0 bottom-0 z-10 flex flex-col items-center md:inset-x-auto md:bottom-4 md:left-1/2 md:w-max md:max-w-[calc(100vw-2rem)] md:-translate-x-1/2",
+        "@container pointer-events-none absolute inset-x-0 bottom-0 z-10 flex flex-col items-center md:bottom-4",
         className,
       )}
     >
-      <div className="mb-3 flex max-w-[calc(100vw-2rem)] flex-wrap items-end justify-center gap-3">
+      <div className="mb-3 flex max-w-[calc(100vw-2rem)] flex-wrap items-end justify-center gap-3 md:w-max">
         <IssuesPanel
           open={issuesOpen}
           issues={issues}
@@ -153,7 +164,7 @@ export function FlowDock({
           <TooltipContent>Add a node (⌘P)</TooltipContent>
         </Tooltip>
 
-        <DockSeparator />
+        <DockSeparator className={SHED} />
 
         {/* A phone pinches to zoom and the graph fits itself, so this would only
           be taking room the rest of the bar needs. */}
@@ -162,7 +173,10 @@ export function FlowDock({
             <Button
               variant="ghost"
               size="icon-touch"
-              className="hidden text-muted-foreground md:inline-flex"
+              className={cn(
+                "hidden text-muted-foreground md:inline-flex",
+                SHED,
+              )}
               onClick={() => fitView({ ...FIT_VIEW, duration: 300 })}
               aria-label="Fit the flow to the screen"
             >
@@ -174,7 +188,7 @@ export function FlowDock({
 
         {issues.length > 0 ? (
           <>
-            <DockSeparator />
+            <DockSeparator className={SHED} />
             <Button
               variant="ghost"
               size="sm-touch"
@@ -197,9 +211,13 @@ export function FlowDock({
           </>
         ) : null}
 
-        <DockSeparator />
+        <DockSeparator className={SHED} />
 
-        <LogsTrigger open={logs.open} onOpenChange={logs.onOpenChange} />
+        <LogsTrigger
+          open={logs.open}
+          onOpenChange={logs.onOpenChange}
+          className={SHED_MORE}
+        />
 
         <Tooltip>
           <TooltipTrigger asChild>
@@ -261,7 +279,7 @@ export function FlowDock({
                 ) : (
                   <Play className="size-4" />
                 )}
-                <span className="hidden md:inline">Run</span>
+                <span className={cn("hidden md:inline", SHED)}>Run</span>
               </Button>
             </span>
           </TooltipTrigger>
@@ -270,7 +288,7 @@ export function FlowDock({
           </TooltipContent>
         </Tooltip>
 
-        <DockSeparator />
+        <DockSeparator className={SHED} />
 
         <Tooltip>
           <TooltipTrigger asChild>

frontend/src/components/Flow/FlowEditor.tsx

@@ -51,6 +51,7 @@ import {
   DialogTitle,
 } from "@/components/ui/dialog"
 import { FluksioLoader } from "@/components/ui/fluksio-loader"
+import { useSidebar } from "@/components/ui/sidebar"
 import useAuth from "@/hooks/useAuth"
 import useCustomToast from "@/hooks/useCustomToast"
 import { useIsMobile } from "@/hooks/useMobile"
@@ -190,6 +191,13 @@ type History = {
 const HISTORY_LIMIT = 50
 const TYPING_WINDOW = 500
 
+/**
+ * Where the dock beside a panel is short of room even with all it sheds
+ * (`FlowDock`): 285px of bar and a margin, the 16rem sidebar and the 27rem
+ * panel. The sidebar folds away while a panel is open here.
+ */
+const CRAMPED = "(min-width: 48rem) and (max-width: 61.75rem)"
+
 /** Nodes copied here, and the code of the ones carrying their own. */
 type NodeClipboard = {
   nodes: NodeDef_Input[]
@@ -867,6 +875,22 @@ function FlowEditorInner({
   // the lanes the bars sit in: publishing is most wanted right after editing.
   const panelOpen = Boolean(selected) || flowPanelOpen
 
+  const [cramped, setCramped] = useState(
+    () => window.matchMedia(CRAMPED).matches,
+  )
+  useEffect(() => {
+    const query = window.matchMedia(CRAMPED)
+    const onChange = () => setCramped(query.matches)
+    query.addEventListener("change", onChange)
+    return () => query.removeEventListener("change", onChange)
+  }, [])
+  const { holdCollapsed } = useSidebar()
+  useEffect(() => {
+    if (!panelOpen || !cramped) return
+    holdCollapsed(true)
+    return () => holdCollapsed(false)
+  }, [panelOpen, cramped, holdCollapsed])
+
   // One effect owns the viewport, so nothing fights over it. Selecting a node
   // brings that node into the lane the panel leaves; every other change to the
   // graph — new wiring, a new endpoint, a panel opening — re-fits the whole flow
@@ -879,6 +903,19 @@ function FlowEditorInner({
   // somewhere the user was already looking, so those stay animated.
   const fitted = useRef(false)
   const centred = useRef<string | null>(null)
+  // The sidebar folding or unfolding resizes the canvas under the view, the
+  // hold above included, so the view is aimed again once it has settled.
+  const [laneMoved, setLaneMoved] = useState(0)
+  useEffect(() => {
+    const onEnd = (event: TransitionEvent) => {
+      const slot = (event.target as HTMLElement).dataset?.slot
+      if (slot !== "sidebar-gap" || event.propertyName !== "width") return
+      centred.current = null
+      setLaneMoved((n) => n + 1)
+    }
+    window.addEventListener("transitionend", onEnd)
+    return () => window.removeEventListener("transitionend", onEnd)
+  }, [])
   // biome-ignore lint/correctness/useExhaustiveDependencies: refit when the shape or the panel changes, not on every render.
   useEffect(() => {
     // Recorded as centred only once the fit below has run: arriving from
@@ -927,6 +964,7 @@ function FlowEditorInner({
     editorExpanded,
     isMobile,
     fitView,
+    laneMoved,
   ])
 
   const runMutation = useMutation({

frontend/src/components/Flow/LogsPanel.tsx

@@ -51,14 +51,19 @@ export type LogsFilter = {
 export function LogsTrigger({
   open,
   onOpenChange,
-}: Pick<LogsFilter, "open" | "onOpenChange">) {
+  className,
+}: Pick<LogsFilter, "open" | "onOpenChange"> & { className?: string }) {
   return (
     <Tooltip>
       <TooltipTrigger asChild>
         <Button
           variant="ghost"
           size="icon-touch"
-          className={cn("text-muted-foreground", open && "text-primary")}
+          className={cn(
+            "text-muted-foreground",
+            open && "text-primary",
+            className,
+          )}
           onClick={() => onOpenChange(!open)}
           aria-pressed={open}
           aria-label="Logs"

frontend/src/components/ui/sidebar.tsx

@@ -34,6 +34,8 @@ type SidebarContextProps = {
   state: "expanded" | "collapsed"
   open: boolean
   setOpen: (open: boolean) => void
+  /** Folds the sidebar away while held, without touching the saved state. */
+  holdCollapsed: (held: boolean) => void
   openMobile: boolean
   setOpenMobile: (open: boolean) => void
   isMobile: boolean
@@ -82,10 +84,14 @@ function SidebarProvider({
   // This is the internal state of the sidebar.
   // We use openProp and setOpenProp for control from outside the component.
   const [_open, _setOpen] = React.useState(getInitialOpen)
-  const open = openProp ?? _open
+  // A screen short of room holds the sidebar folded. Letting go brings back
+  // whatever was saved, and a toggle meanwhile is the user's and wins.
+  const [held, holdCollapsed] = React.useState(false)
+  const open = (openProp ?? _open) && !held
   const setOpen = React.useCallback(
     (value: boolean | ((value: boolean) => boolean)) => {
       const openState = typeof value === "function" ? value(open) : value
+      holdCollapsed(false)
       if (setOpenProp) {
         setOpenProp(openState)
       } else {
@@ -128,6 +134,7 @@ function SidebarProvider({
       state,
       open,
       setOpen,
+      holdCollapsed,
       isMobile,
       openMobile,
       setOpenMobile,