diff --git a/web/src/App.tsx b/web/src/App.tsx
index 843e624..749c9ba 100644
--- a/web/src/App.tsx
+++ b/web/src/App.tsx
@@ -1,4 +1,4 @@
-import { useEffect, useMemo, useRef, useState } from "preact/hooks";
+import { useEffect, useLayoutEffect, useMemo, useRef, useState } from "preact/hooks";
 import type { TargetedTouchEvent } from "preact";
 import {
   Check,
@@ -654,9 +654,10 @@ type ModelComboboxProps = {
   value: string;
   onChange: (value: string) => void;
   disabled?: boolean;
+  className?: string;
 };
 
-function ModelCombobox({ options, value, onChange, disabled = false }: ModelComboboxProps) {
+function ModelCombobox({ options, value, onChange, disabled = false, className }: ModelComboboxProps) {
   const [open, setOpen] = useState(false);
   const [draftValue, setDraftValue] = useState(value);
   const rootRef = useRef<HTMLDivElement>(null);
@@ -710,7 +711,12 @@ function ModelCombobox({ options, value, onChange, disabled = false }: ModelComb
 
   return (
     <div className="relative" ref={rootRef}>
-      <div className="flex h-10 min-w-56 items-center rounded-lg border border-violet-300/22 bg-background/72 px-3 text-sm shadow-[inset_0_1px_0_hsl(255_100%_92%_/_0.06)]">
+      <div
+        className={cn(
+          "flex h-10 min-w-56 items-center rounded-lg border border-violet-300/22 bg-background/72 px-3 text-sm shadow-[inset_0_1px_0_hsl(255_100%_92%_/_0.06)]",
+          className
+        )}
+      >
         <input
           ref={inputRef}
           value={draftValue}
@@ -1018,6 +1024,7 @@ export default function App() {
   const transcriptEndRef = useRef<HTMLDivElement>(null);
   const contextMenuRef = useRef<HTMLDivElement>(null);
   const renameChatInputRef = useRef<HTMLInputElement>(null);
+  const chatSettingsDialogRef = useRef<HTMLDialogElement>(null);
   const fileInputRef = useRef<HTMLInputElement>(null);
   const dragDepthRef = useRef(0);
   const pendingAttachmentsRef = useRef<ChatAttachment[]>([]);
@@ -1930,6 +1937,7 @@ export default function App() {
     if (!isAuthenticated) return;
 
     const handleKeyDown = (event: KeyboardEvent) => {
+      if (chatSettingsDialogRef.current?.open) return;
       const hasPrimaryModifier = event.metaKey || event.ctrlKey;
       if (!hasPrimaryModifier || event.altKey) return;
 
@@ -2331,16 +2339,16 @@ export default function App() {
     return () => window.clearTimeout(timer);
   }, [renameChatDialog]);
 
-  useEffect(() => {
+  useLayoutEffect(() => {
     if (!isChatSettingsOpen) return;
-    const handleKeyDown = (event: KeyboardEvent) => {
-      if (event.key !== "Escape" || isSavingChatSettings) return;
-      event.preventDefault();
-      setIsChatSettingsOpen(false);
+    const dialog = chatSettingsDialogRef.current;
+    const previouslyFocused = document.activeElement;
+    dialog?.showModal();
+    return () => {
+      dialog?.close();
+      if (previouslyFocused instanceof HTMLElement) previouslyFocused.focus({ preventScroll: true });
     };
-    window.addEventListener("keydown", handleKeyDown);
-    return () => window.removeEventListener("keydown", handleKeyDown);
-  }, [isChatSettingsOpen, isSavingChatSettings]);
+  }, [isChatSettingsOpen]);
 
   useEffect(() => {
     if (!isQuickQuestionOpen) return;
@@ -3822,44 +3830,66 @@ export default function App() {
         </div>
       ) : null}
       {isChatSettingsOpen ? (
-        <div
-          className="fixed inset-0 z-[60] flex items-center justify-center bg-black/72 p-3 backdrop-blur-md md:p-6"
+        <dialog
+          ref={chatSettingsDialogRef}
+          aria-labelledby="chat-settings-title"
+          className="fixed inset-0 m-0 flex h-dvh max-h-none w-full max-w-none items-center justify-center overflow-hidden bg-transparent p-0 text-foreground backdrop:bg-black/70 backdrop:backdrop-blur-md md:p-6"
+          onCancel={(event) => {
+            event.preventDefault();
+            if (!isSavingChatSettings) setIsChatSettingsOpen(false);
+          }}
           onMouseDown={(event) => {
             if (event.target === event.currentTarget && !isSavingChatSettings) setIsChatSettingsOpen(false);
           }}
         >
           <form
-            role="dialog"
-            aria-modal="true"
-            aria-labelledby="chat-settings-title"
-            className="glass-panel flex max-h-[88vh] w-full max-w-2xl flex-col rounded-2xl border border-violet-300/24 p-4 shadow-2xl shadow-black/45 md:p-5"
+            className="glass-panel flex h-full min-h-0 w-full flex-col overflow-hidden md:h-auto md:max-h-full md:max-w-2xl md:rounded-2xl md:border md:border-violet-300/24"
             onSubmit={(event) => void handleChatSettingsSubmit(event)}
           >
-            <div className="mb-4 flex items-center justify-between gap-3">
+            <div className="chat-settings-header grid shrink-0 grid-cols-[minmax(0,1fr)_auto_minmax(0,1fr)] items-center gap-2 border-b border-violet-300/16 md:flex md:justify-between md:gap-3">
+              <Button
+                type="button"
+                variant="ghost"
+                className="h-11 justify-self-start px-2 text-violet-200 hover:bg-violet-400/10 hover:text-violet-100 md:hidden"
+                onClick={() => setIsChatSettingsOpen(false)}
+                disabled={isSavingChatSettings}
+              >
+                Cancel
+              </Button>
               <div className="min-w-0">
-                <h2 id="chat-settings-title" className="text-sm font-semibold text-violet-50">
+                <h2 id="chat-settings-title" className="text-base font-semibold text-violet-50 md:text-sm">
                   Chat settings
                 </h2>
-                <p className="mt-1 truncate text-xs text-muted-foreground">{chatSettingsTitleDraft.trim() || "New chat"}</p>
+                <p className="mt-1 hidden truncate text-xs text-muted-foreground md:block">{chatSettingsTitleDraft.trim() || "New chat"}</p>
               </div>
               <Button
                 type="button"
                 size="icon"
                 variant="ghost"
-                className="h-8 w-8"
+                className="hidden h-8 w-8 shrink-0 md:inline-flex"
                 onClick={() => setIsChatSettingsOpen(false)}
                 disabled={isSavingChatSettings}
                 aria-label="Close chat settings"
               >
                 <X className="h-4 w-4" />
               </Button>
+              <Button
+                type="submit"
+                variant="ghost"
+                className="h-11 justify-self-end gap-1.5 px-2 font-semibold text-violet-200 hover:bg-violet-400/10 hover:text-violet-100 md:hidden"
+                disabled={isSavingChatSettings}
+              >
+                {isSavingChatSettings ? <LoaderCircle className="h-4 w-4 animate-spin" /> : null}
+                Save
+              </Button>
             </div>
 
-            <div className="min-h-0 flex-1 space-y-4 overflow-y-auto pr-1">
+            <div className="chat-settings-content min-h-0 flex-1 space-y-5 overflow-y-auto overscroll-contain md:space-y-4">
               <div>
-                <span className="mb-1.5 block text-xs font-semibold text-violet-100/72">Chat title</span>
+                <label for="chat-settings-chat-title" className="mb-1.5 block text-xs font-semibold text-violet-100/72">Chat title</label>
                 <div className="flex items-center gap-2">
                   <input
+                    id="chat-settings-chat-title"
                     value={chatSettingsTitleDraft}
                     onInput={(event) => {
                       setChatSettingsTitleDraft(event.currentTarget.value);
@@ -3867,7 +3897,7 @@ export default function App() {
                     }}
                     maxLength={120}
                     placeholder={draftKind === null && selectedItem?.kind === "chat" ? "Chat title" : "Optional title"}
-                    className="h-11 min-w-0 flex-1 rounded-lg border border-violet-300/22 bg-background/72 px-3 text-sm text-violet-50 outline-none shadow-[inset_0_1px_0_hsl(255_100%_92%_/_0.06)] placeholder:text-muted-foreground focus:border-violet-300/45 focus:ring-1 focus:ring-ring/70"
+                    className="h-11 min-w-0 flex-1 rounded-lg border border-violet-300/22 bg-background/70 px-3 text-base text-violet-50 outline-none shadow-[inset_0_1px_0_hsl(255_100%_92%_/_0.06)] placeholder:text-muted-foreground focus:border-violet-300/45 focus:ring-1 focus:ring-ring/70 md:text-sm"
                     disabled={isSavingChatSettings}
                   />
                   {chatSettingsChatId ? (
@@ -3895,7 +3925,7 @@ export default function App() {
                 <label className="block">
                   <span className="mb-1.5 block text-xs font-semibold text-violet-100/72">Provider</span>
                   <select
-                    className="h-10 w-full rounded-lg border border-violet-300/22 bg-background/72 px-3 text-sm text-violet-50 outline-none shadow-[inset_0_1px_0_hsl(255_100%_92%_/_0.06)] focus:border-violet-300/45 focus:ring-1 focus:ring-ring/70"
+                    className="h-11 w-full rounded-lg border border-violet-300/22 bg-background/70 px-3 text-base text-violet-50 outline-none shadow-[inset_0_1px_0_hsl(255_100%_92%_/_0.06)] focus:border-violet-300/45 focus:ring-1 focus:ring-ring/70 md:h-10 md:text-sm"
                     value={chatSettingsProviderDraft}
                     onChange={(event) => {
                       const nextProvider = event.currentTarget.value as Provider;
@@ -3917,6 +3947,7 @@ export default function App() {
                 <label className="block min-w-0">
                   <span className="mb-1.5 block text-xs font-semibold text-violet-100/72">Model</span>
                   <ModelCombobox
+                    className="h-11 min-w-0 bg-background/70 text-base md:h-10 md:text-sm"
                     options={chatSettingsProviderModelOptions}
                     value={chatSettingsModelDraft}
                     disabled={isSavingChatSettings}
@@ -3938,7 +3969,7 @@ export default function App() {
                     if (chatSettingsError) setChatSettingsError(null);
                   }}
                   placeholder="Add per-chat instructions"
-                  className="min-h-32 resize-y border-violet-300/24 bg-background/72 text-sm text-violet-50 placeholder:text-violet-200/45"
+                  className="min-h-32 resize-y border-violet-300/24 bg-background/70 text-base text-violet-50 placeholder:text-violet-200/45 md:text-sm"
                   disabled={isSavingChatSettings}
                 />
               </label>
@@ -3952,6 +3983,7 @@ export default function App() {
                         type="button"
                         size="sm"
                         variant="secondary"
+                        className="h-11 gap-1.5 md:h-8"
                         onClick={() => setChatSettingsEnabledToolsDraft(getDefaultEnabledTools(availableChatTools))}
                         disabled={isSavingChatSettings}
                       >
@@ -3962,6 +3994,7 @@ export default function App() {
                         type="button"
                         size="sm"
                         variant="secondary"
+                        className="h-11 gap-1.5 md:h-8"
                         onClick={() => setChatSettingsEnabledToolsDraft([])}
                         disabled={isSavingChatSettings}
                       >
@@ -3971,31 +4004,30 @@ export default function App() {
                     </div>
                   ) : null}
                 </div>
-                <div className="space-y-2">
+                <div className="grid gap-2 md:grid-cols-2">
                   {availableChatTools.length ? (
                     availableChatTools.map((tool) => {
                       const checked = chatSettingsEnabledToolsDraft.includes(tool.name);
                       return (
                         <label
                           key={tool.name}
-                          className="flex cursor-pointer items-start gap-3 rounded-lg border border-violet-300/18 bg-background/44 px-3 py-2.5 transition hover:border-violet-300/34 hover:bg-violet-400/8"
+                          title={tool.description}
+                          className="flex min-h-11 min-w-0 cursor-pointer items-center gap-3 rounded-lg border border-violet-300/18 bg-background/44 px-3 py-2.5 transition hover:border-violet-300/34 hover:bg-violet-400/8 focus-within:border-violet-300/45 focus-within:ring-1 focus-within:ring-ring/70"
                         >
                           <input
                             type="checkbox"
                             checked={checked}
                             onChange={() => toggleChatSettingsTool(tool.name)}
-                            className="mt-1 h-4 w-4 rounded border-violet-300/35 bg-background/80 accent-violet-400"
+                            className="h-4 w-4 shrink-0 rounded border-violet-300/35 bg-background/80 accent-violet-400"
+                            aria-description={tool.description}
                             disabled={isSavingChatSettings}
                           />
-                          <span className="min-w-0">
-                            <span className="block text-sm font-medium text-violet-50">{getToolLabel(tool.name)}</span>
-                            <span className="mt-0.5 block text-xs leading-5 text-muted-foreground">{tool.description}</span>
-                          </span>
+                          <span className="min-w-0 break-words text-sm font-medium text-violet-50">{getToolLabel(tool.name)}</span>
                         </label>
                       );
                     })
                   ) : (
-                    <p className="rounded-lg border border-violet-300/18 bg-background/44 px-3 py-2.5 text-sm text-muted-foreground">
+                    <p className="rounded-lg border border-violet-300/18 bg-background/44 px-3 py-2.5 text-sm text-muted-foreground md:col-span-2">
                       No chat tools are available.
                     </p>
                   )}
@@ -4003,8 +4035,8 @@ export default function App() {
               </section>
             </div>
 
-            {chatSettingsError ? <p className="mt-3 text-sm text-rose-300">{chatSettingsError}</p> : null}
-            <div className="mt-4 flex justify-end gap-2">
+            {chatSettingsError ? <p role="alert" className="chat-settings-error shrink-0 break-words border-t border-violet-300/16 text-sm text-rose-300">{chatSettingsError}</p> : null}
+            <div className="hidden shrink-0 justify-end gap-2 border-t border-violet-300/16 p-5 md:flex">
               <Button type="button" variant="secondary" onClick={() => setIsChatSettingsOpen(false)} disabled={isSavingChatSettings}>
                 Cancel
               </Button>
@@ -4014,7 +4046,7 @@ export default function App() {
               </Button>
             </div>
           </form>
-        </div>
+        </dialog>
       ) : null}
       {renameChatDialog ? (
         <div
diff --git a/web/src/index.css b/web/src/index.css
index 005e3e8..26c77da 100644
--- a/web/src/index.css
+++ b/web/src/index.css
@@ -113,7 +113,41 @@ textarea {
     max(0.75rem, var(--safe-area-left));
 }
 
+.chat-settings-header {
+  padding:
+    calc(0.5rem + var(--safe-area-top))
+    max(0.75rem, var(--safe-area-right))
+    0.5rem
+    max(0.75rem, var(--safe-area-left));
+}
+
+.chat-settings-content {
+  padding:
+    1rem
+    max(1rem, var(--safe-area-right))
+    max(1.5rem, var(--safe-area-bottom))
+    max(1rem, var(--safe-area-left));
+  scroll-padding-block: 1rem;
+}
+
+.chat-settings-error {
+  padding:
+    0.75rem
+    max(1rem, var(--safe-area-right))
+    max(0.75rem, var(--safe-area-bottom))
+    max(1rem, var(--safe-area-left));
+}
+
 @media (min-width: 768px) {
+  .chat-settings-header,
+  .chat-settings-content {
+    padding: 1.25rem;
+  }
+
+  .chat-settings-error {
+    padding: 0.75rem 1.25rem;
+  }
+
   .app-safe-frame {
     padding:
       max(0.5rem, var(--safe-area-top))