diff --git a/src/browser/components/ProjectSidebar.tsx b/src/browser/components/ProjectSidebar.tsx
index aea8484a7..46159c5d3 100644
--- a/src/browser/components/ProjectSidebar.tsx
+++ b/src/browser/components/ProjectSidebar.tsx
@@ -23,7 +23,7 @@ import { TooltipWrapper, Tooltip } from "./Tooltip";
 import SecretsModal from "./SecretsModal";
 import type { Secret } from "@/common/types/secrets";
 import { ForceDeleteModal } from "./ForceDeleteModal";
-import { WorkspaceListItem } from "./WorkspaceListItem";
+import { WorkspaceListItem, type WorkspaceSelection } from "./WorkspaceListItem";
 import { RenameProvider } from "@/browser/contexts/WorkspaceRenameContext";
 import { useProjectContext } from "@/browser/contexts/ProjectContext";
 import { ChevronRight, KeyRound } from "lucide-react";
@@ -194,6 +194,31 @@ const ProjectSidebarInner: React.FC<ProjectSidebarProps> = ({
     updateSecrets: onUpdateSecrets,
   } = useProjectContext();
 
+  // Mobile breakpoint for auto-closing sidebar
+  const MOBILE_BREAKPOINT = 768;
+
+  // Wrapper to close sidebar on mobile after workspace selection
+  const handleSelectWorkspace = useCallback(
+    (selection: WorkspaceSelection) => {
+      onSelectWorkspace(selection);
+      if (window.innerWidth <= MOBILE_BREAKPOINT && !collapsed) {
+        onToggleCollapsed();
+      }
+    },
+    [onSelectWorkspace, collapsed, onToggleCollapsed]
+  );
+
+  // Wrapper to close sidebar on mobile after adding workspace
+  const handleAddWorkspace = useCallback(
+    (projectPath: string) => {
+      onAddWorkspace(projectPath);
+      if (window.innerWidth <= MOBILE_BREAKPOINT && !collapsed) {
+        onToggleCollapsed();
+      }
+    },
+    [onAddWorkspace, collapsed, onToggleCollapsed]
+  );
+
   // Workspace-specific subscriptions moved to WorkspaceListItem component
 
   // Store as array in localStorage, convert to Set for usage
@@ -427,13 +452,13 @@ const ProjectSidebarInner: React.FC<ProjectSidebarProps> = ({
       // Create new workspace for the project of the selected workspace
       if (matchesKeybind(e, KEYBINDS.NEW_WORKSPACE) && selectedWorkspace) {
         e.preventDefault();
-        onAddWorkspace(selectedWorkspace.projectPath);
+        handleAddWorkspace(selectedWorkspace.projectPath);
       }
     };
 
     window.addEventListener("keydown", handleKeyDown);
     return () => window.removeEventListener("keydown", handleKeyDown);
-  }, [selectedWorkspace, onAddWorkspace]);
+  }, [selectedWorkspace, handleAddWorkspace]);
 
   return (
     <RenameProvider onRenameWorkspace={onRenameWorkspace}>
@@ -575,7 +600,7 @@ const ProjectSidebarInner: React.FC<ProjectSidebarProps> = ({
                           >
                             <div className="border-hover border-b px-3 py-2">
                               <button
-                                onClick={() => onAddWorkspace(projectPath)}
+                                onClick={() => handleAddWorkspace(projectPath)}
                                 data-project-path={projectPath}
                                 aria-label={`Add workspace to ${projectName}`}
                                 className="text-muted border-border-medium hover:bg-hover hover:border-border-darker hover:text-foreground w-full cursor-pointer rounded border border-dashed bg-transparent px-3 py-1.5 text-left text-[13px] transition-all duration-200"
@@ -602,7 +627,7 @@ const ProjectSidebarInner: React.FC<ProjectSidebarProps> = ({
                                   isSelected={selectedWorkspace?.workspaceId === metadata.id}
                                   isDeleting={deletingWorkspaceIds.has(metadata.id)}
                                   lastReadTimestamp={lastReadTimestamps[metadata.id] ?? 0}
-                                  onSelectWorkspace={onSelectWorkspace}
+                                  onSelectWorkspace={handleSelectWorkspace}
                                   onRemoveWorkspace={handleRemoveWorkspace}
                                   onToggleUnread={_onToggleUnread}
                                 />
diff --git a/src/browser/components/Settings/SettingsModal.tsx b/src/browser/components/Settings/SettingsModal.tsx
index fc91fa828..3a5a5eeea 100644
--- a/src/browser/components/Settings/SettingsModal.tsx
+++ b/src/browser/components/Settings/SettingsModal.tsx
@@ -63,22 +63,31 @@ export function SettingsModal() {
         aria-modal="true"
         aria-labelledby="settings-title"
         onClick={(e) => e.stopPropagation()}
-        className="bg-dark border-border flex h-[70vh] max-h-[600px] w-[90%] max-w-[800px] overflow-hidden rounded-lg border shadow-lg"
+        className="bg-dark border-border flex h-[80vh] max-h-[600px] w-[95%] max-w-[800px] flex-col overflow-hidden rounded-lg border shadow-lg md:h-[70vh] md:flex-row"
       >
-        {/* Sidebar */}
-        <div className="border-border-medium flex w-48 shrink-0 flex-col border-r">
-          <div className="border-border-medium flex h-12 items-center border-b px-4">
+        {/* Sidebar - horizontal tabs on mobile, vertical on desktop */}
+        <div className="border-border-medium flex shrink-0 flex-col border-b md:w-48 md:border-r md:border-b-0">
+          <div className="border-border-medium flex h-12 items-center justify-between border-b px-4 md:justify-start">
             <span id="settings-title" className="text-foreground text-sm font-semibold">
               Settings
             </span>
+            {/* Close button in header on mobile only */}
+            <button
+              type="button"
+              onClick={handleClose}
+              className="text-muted hover:text-foreground rounded p-1 transition-colors md:hidden"
+              aria-label="Close settings"
+            >
+              <X className="h-4 w-4" />
+            </button>
           </div>
-          <nav className="flex-1 overflow-y-auto p-2">
+          <nav className="flex overflow-x-auto p-2 md:flex-1 md:flex-col md:overflow-y-auto">
             {SECTIONS.map((section) => (
               <button
                 key={section.id}
                 type="button"
                 onClick={() => setActiveSection(section.id)}
-                className={`flex w-full items-center gap-2 rounded-md px-3 py-2 text-left text-sm transition-colors ${
+                className={`flex shrink-0 items-center gap-2 rounded-md px-3 py-2 text-left text-sm whitespace-nowrap transition-colors md:w-full ${
                   activeSection === section.id
                     ? "bg-accent/20 text-accent"
                     : "text-muted hover:bg-hover hover:text-foreground"
@@ -92,8 +101,8 @@ export function SettingsModal() {
         </div>
 
         {/* Content */}
-        <div className="flex flex-1 flex-col overflow-hidden">
-          <div className="border-border-medium flex h-12 items-center justify-between border-b px-6">
+        <div className="flex min-h-0 flex-1 flex-col overflow-hidden">
+          <div className="border-border-medium hidden h-12 items-center justify-between border-b px-6 md:flex">
             <span className="text-foreground text-sm font-medium">{currentSection.label}</span>
             <button
               type="button"
@@ -104,7 +113,7 @@ export function SettingsModal() {
               <X className="h-4 w-4" />
             </button>
           </div>
-          <div className="flex-1 overflow-y-auto p-6">
+          <div className="flex-1 overflow-y-auto p-4 md:p-6">
             <SectionComponent />
           </div>
         </div>
diff --git a/src/browser/components/Settings/sections/ModelRow.tsx b/src/browser/components/Settings/sections/ModelRow.tsx
index 69d057bec..418b8a6de 100644
--- a/src/browser/components/Settings/sections/ModelRow.tsx
+++ b/src/browser/components/Settings/sections/ModelRow.tsx
@@ -26,12 +26,12 @@ export interface ModelRowProps {
 
 export function ModelRow(props: ModelRowProps) {
   return (
-    <div className="border-border-medium bg-background-secondary flex items-center justify-between rounded-md border px-3 py-1.5">
-      <div className="flex min-w-0 flex-1 items-center gap-2">
+    <div className="border-border-medium bg-background-secondary flex items-center justify-between gap-2 rounded-md border px-2 py-1.5 md:px-3">
+      <div className="flex min-w-0 flex-1 items-center gap-1.5 md:gap-2">
         <ProviderWithIcon
           provider={props.provider}
           displayName
-          className="text-muted w-20 shrink-0 text-xs"
+          className="text-muted w-16 shrink-0 text-xs md:w-20"
         />
         {props.isEditing ? (
           <div className="flex min-w-0 flex-1 items-center gap-1">
diff --git a/src/browser/components/Settings/sections/ModelsSection.tsx b/src/browser/components/Settings/sections/ModelsSection.tsx
index 705c0359b..3d1f8d525 100644
--- a/src/browser/components/Settings/sections/ModelsSection.tsx
+++ b/src/browser/components/Settings/sections/ModelsSection.tsx
@@ -160,11 +160,11 @@ export function ModelsSection() {
 
         {/* Add new model form */}
         <div className="border-border-medium bg-background-secondary rounded-md border p-2">
-          <div className="flex gap-1.5">
+          <div className="flex flex-wrap gap-1.5">
             <select
               value={newModel.provider}
               onChange={(e) => setNewModel((prev) => ({ ...prev, provider: e.target.value }))}
-              className="bg-modal-bg border-border-medium focus:border-accent rounded border px-2 py-1 text-xs focus:outline-none"
+              className="bg-modal-bg border-border-medium focus:border-accent shrink-0 rounded border px-2 py-1 text-xs focus:outline-none"
             >
               <option value="">Provider</option>
               {SUPPORTED_PROVIDERS.map((p) => (
@@ -178,7 +178,7 @@ export function ModelsSection() {
               value={newModel.modelId}
               onChange={(e) => setNewModel((prev) => ({ ...prev, modelId: e.target.value }))}
               placeholder="model-id"
-              className="bg-modal-bg border-border-medium focus:border-accent flex-1 rounded border px-2 py-1 font-mono text-xs focus:outline-none"
+              className="bg-modal-bg border-border-medium focus:border-accent min-w-0 flex-1 rounded border px-2 py-1 font-mono text-xs focus:outline-none"
               onKeyDown={(e) => {
                 if (e.key === "Enter") void handleAddModel();
               }}
@@ -187,7 +187,7 @@ export function ModelsSection() {
               type="button"
               onClick={handleAddModel}
               disabled={!newModel.provider || !newModel.modelId.trim()}
-              className="bg-accent hover:bg-accent-dark disabled:bg-border-medium flex items-center gap-1 rounded px-2 py-1 text-xs text-white transition-colors disabled:cursor-not-allowed"
+              className="bg-accent hover:bg-accent-dark disabled:bg-border-medium flex shrink-0 items-center gap-1 rounded px-2 py-1 text-xs text-white transition-colors disabled:cursor-not-allowed"
             >
               <Plus className="h-3.5 w-3.5" />
               Add